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Published Aug "1.2801 


THE 


PHILOSOPHICAL MAGAZINE: 


COMPREHENDING , 
THE VARIOUS BRANCHES OF SCIENCE, 
THE LIBERAL AND FINE ARTS, 
AGRICULTURE, MANUFACTURES, 


AND 


COMMERCE. 


Seg ee 


BY ALEXANDER TILLOCH, 
BEMBER OF THE LONDON PHILOSOPHICAL soctETyY, &c. 


ee ee 


t 


‘¢ Nec aranearum fane textus ideo melior, quia ex fe fila gignunt. Nec nofter 
vilior quia ex alienis libamus ut apes.” Just. Lies. Afonit. Polit. lib. i. eap. 1. 


LONDON: 
PRINTED BY J. DAVIS, CHANCERY-LANE, 

For Atexanper Tittocn; and fold by Mefirs. Ricnarpson, 
Cornhill; Capretz and Davies, Strand; Desrert, Piccadilly ; 
Murray and Hicutey, No. 32, Fleet-ttreet ; Symonns, 
Paternofter-Row ; Brit, No. 148, Oxford-ftreet ; 
Verwnor and Hoop, Poultry; Harpine, No. 36, 

St. James’s-ftreet; Westiey, No.1 59, Strand; 

J. Remnant, High-ftreet, Bloomfbury ; 

W. Remnant, Hamburgh; and 
W. Gixipsrt, Dublin, 


CONTENTS 
on TaE 


FIFTH VOLUME. 


OBSERVATIONS on Animal Eleétricity, and particularly 
_ that called Spentaneous. By J.J.HEMMER. Pagel, 140 
On the Method of Dijiilling as prattifed by the Natives at 
Chatra in Ramgur, and other Parts of India. By ARCHi- 
BALD Kerr, E/g. Sea See e yeuiie Tae 
On the Method abet at Fez. and Tetuan to prepare thofe 
Goat Skins called Morocco. ByC, A.BRoUssONET 14 
Recipe for deflroying Caterpillars on Goofeberry Bufbes 16 
On the Gradual Changes in Temperature and Soil which take 
place in different Climates, with an Enquiry into the Caufe 
of thofe Changes. By the Abbi MANN . | =. 18 
Agenda, or a Colleétion of Obfervations and Refearches, the 
Refults of which may ferve as the Foundation for a Theory 

of the Earth. By M. DE SAUSSURE 245 135, 217 
On the Effeéts produced on different Kinds of Stones by the 
Vapour of the Fluor Acid. By M. Kortum, of Warfaw 29 
An Eafy and Cheap Method of preparing Sal Aératus, (Car- 
bonat of Pot-afb.) By E. A. HOLYOKE, M. D. of Salem, 
Maffachujitts - pais aid - ey 36 
Communication from Capel Lofft, E/g. refpetting the late 
Meteor and Comet RET ase - . 38 
Defeription of a Blaft-Furnace for fmelting Iron from the Ore, 
with that Part of the Blowing-Machine immediately con~ 
netted with it. By Mr. Davin MusueEt, of the Clyde 

_ Tron-Works. Communicated by the Author | = 40 
Extra&é of a firft Memoir to ferve as a Natural, Chemical, 
and Medical Hiflory of Human Urine; with fome new 
Faéis on its Analyfis and Spontaneous Alteration, By C. 
Fourcroy and VAUQUELIN Be as 43 
Extraét from the Report refpettin Experiments made at the 
Polytechnic School in the Years V. and VI. on the Combuf- 
_tion of the Diamond. By C. GuyToNn 4555, 174 
Account of the Proceffes ufed by Mr, SHELDRAKE to fepa-, 
rate the Mucilage from Linjced Oil, and to diffolve Copal 
in Spirit of Turpentine and in Alcebal - on ae 
Ag Proce/s 


iv CONTENTS. 


Proce/s for producing the Lights in Stained Drawings. By Mr. 
Francis NicHOLsoN; of Rippon, Yorkfbire Page 67 

An Account of Mr: Brown’s Travels Erne Egypt and 
Syria, &e. - 69, 192 

Defcription of the Paliortim ‘hane, “ or Lake ‘Pala, in the 
Valley of Noto im Stcily. ByM.Dotomiru - 47 
Obfervations on the Nature of the Fog of 1783. By M. Dr 
LAMawon, aT of the "Acaitemy of adie: 
Paris - 

Report ow the Conmveninn: of Soft & on into Caft Steel, by means 
of the Diamond. Read in the French National Inftitute, 
Tbermidor 26, Year 7. By C: Guyton - 89 

Communications * fr om Dr. THORNTON, Phyfician to the 
“General Difpenfaty, &e. &c. &c. relative s Pneumatic 
‘Medicine 4; 196, 291 

Obfervations on the ae o. Ae oF the Ataipere fxs 
the Abbe Mann 105 

On the Nature and eae of Hi Sun iy Fixed Stars. 
By WiLtiaAM HerscueE., LL.D. F.R.S. 114, 222 

On the Production of Caft Iron, and the Operations of the 
Blaft-Furnace, By Mr. Davivn Musuet, of the Clyde 
Tron-Works. - Communicated by the Author ~ 124 

Objervations on Pot-af/b ; bemg an Inquiry how far the mif- 
chievous Eiffeéis of Septic Acid are reflrained by Pot-a/b 
and other Malin particularly in refpeét to the Effects of 
Septite of Pot-a/b (Nitre or Saltpetre) upon Animal Flefh - 
intended to be eaten, and upon the Human Stomach; ina 
Letter from Dr, Mitchill to Dr. Prieftley, dated Plandome, 
~ May 4,1799. Communicated by Dr. MiTCHILL 146 

Defcription of a Mercurial Gazometer conftruéted by Mr. 
W.H. Purys jun. . Communicated by the Author 154. 

A Communication réfpeding the ie Saas 4 of sige Ink. 
By Mr, DrsonMESUx jun. 157 

An Inquiry concerning the Weight aa, to pba By 
BenzJAMin Count Rumeorb, F.R.S.M. RIA. &c. 


Read before the Royal Society May 2, 1799 - 162 
A Letter, to the Editor, containing vier Objeétions to the 
Mitchillian Theory of Peflilential “Fluids - 188 


Defcription of Mr. Howann’s Amproved Air-Furnace 190 

On different Sorts of Lime ufed in Agriculture. By SMITH- 
son TENNANT, Ej/g. VRS. - - 209. 

Extra& of a Memoir, and E:xperiments on the Nutrition of 
Plants. By M. RarFn, Affe vo? in the Office of. Commerce 
at Cope nbag ren 738 

On the Affaying of Iron Ones oo Tron- he: by Fufon. By 

» Mr. Davip Musuet, of the Clyde Iron-Works 3 


5 i 


CONTENTS. ¥ 


On the real Origin of that Refin known under the Name of 
Sandarac, and-that of Gum Arabic. By M.ScHOUSBOE 
Page 239 

On the Peftilential Difeafes which, at different times, ap- 
peared in the Athenian, Carthaginian and Roman Armies, 
in the Neighbourhood of eee @. By thé late ok. Sr 
Smitru, Phy/ician 

Obfervations on the Art of Scouring di iforent Kinds of Stuff 
By C. CHaPrTaL 26% 

Defcription of some Biuprduements died abe by Mr. JAMES 
Burns, of Gla/zow, applicable to Fire-Grates, Stoves, 
&c. by which Rooms and Halls of every De/cription may 
be heated more fpeedily and effectually, and with a fmaller 
Wafle of Fuel, than by the’Methods now in Ufe - .264 

On the Chemical A&ion of di ifferent Metals on each other at 
the common hi sah of the oer By C. Faz- 
BRONI - 268 

On the Art of Hardening Capes By P. i HseEwtM = 271 

Experiments on the Nature and Properties of the Pietra Ae 
gaja, Lapis fungifer. By P. A. GADD - 

On the Volcanic Tfland thrown up in the Ne awe 0. 
Iceland. By eg Von HOWSASEN, of the Danifh 
Navy - - - 280 

te cass on fome ‘peailian Matters dah from Animal 
Subfbances treated with the Nitric Acid. By C. WEL~ 
TER ~ 286 

Refleétions on the Gakhiy of Earthen Wate. and the Refults 
of the Analyfis of fome Earths and common Kinds of 
Earthen-Ware. By C. VAUQUELIN 288 

A Communication from GEORGE PEARSON, M. D. F.R.S. 

&c. Phyfician to St. George’s Hofpital, &c. concerning 

Eruptions refembling the Small-Pox, which itive ap~ 


pear in the Inoculated Vaccine Difeafe = 13 
Obfervations refpecting the Earthquake which pay place im 
Peru in the year 1797. By M. CAVANILLES 318 


Experiments to determine the Quantity of Tanning Principle 
and Gallic Acid contained in the Bark of various Trees. 


By Georce Bieein, E/q. 321 
Extra& of a Memoir on the Grecian Method of dyeing Cotton 
Yarn Red. By C, FELIX 325 
An Account of “th Wild Hoge in Spaniph Agere wis 


D. FeLix AzARA 339 
An Account of the Pearl Fiery i in the Gulph of Manar, in 
March and April 1797. By Hunry J. Le Beck, E/g. 
335 


Account 


i CONTENTS. 

Account of a new Method of Bleaching Cotton. By os 
-CuapraL, Member of the National Infitute Page 35% 
On the Method of preparing Inks that will withfland the 
Agiion of the Oxygenated Muriatic Acid. By A. Bosse, 
of Hamburgh - - - - 353 
- Sketch of the Hifiory of Mining in Devon and Cornwall. By 
Mr. Joun Tayior jun. Miner, Taviflock.  Communi- 
cated by the Author. - - - 357 
On the relative Proportions of Coals and Iron-Stones wfed at 
the Blaft-Furnace, and of their proper Application to Ufe. 
By Mr. Davip Musuert, of the Clyde Iron-Works. 
Communicated by the Author - - 366 
A new Theory, pointing out the Situation of the Magnetic 
' Poles, and a Method of difcovering the Lorigitude. By 
P.R. Nucent, E/q. formerly Surveyor-General of Lands 
for the Ifland of Cape Breton. Communicated by the Author 
378 
Defeription of a Portable Machine for loading and unloading 

Goods. By Mr. Georce Davis, of Windfor, Berks 


392 
Defcription of a cheap and efficacious Ventilator for preferving 
Corn on Ship-board. By Tuomas SoutH, E/q. 393 


Intelligence and Mifcellaneous Articles 95, 197, 296, 402 


THE 


THE 


PHILOSOPHICAL MAGAZINE. 


OCTOBER 1790. 


I. Obfervations on Animal EleGricity, and particularly that 
called Spontaneous. By J.J. HEMMER*. 


Unorr Animal Ele&ricity I underftand that kind ob- 
ferved in animals, from whatever caufe it may arife. When 
‘this electricity is excited in animals, neither by the peculiar 
movement of their own bodies, nor by friétion, or the appli- 
cation of any other body, it is called Spontaneous Animal 
EleGricity. We are taught by many inftances, both an- 
cient and modern, that men, as well as other animals, have 
exhibited evident figns of ele&tricity; although the ancients, 
who mention thefe inftances, did not know to what the 
phenomenon was to be afcribed. It may not be improper, 
therefore, to quote here fome of the moft remarkable of them. 
I, We are told by Virgil, that the hair of Afcanius emitted 
a harmlefs kind of flame t. 
Ecce levis fummo de vertice vifus Iuli 
Fundere lumen apex, ta€tuque innoxia molli 
Lambere flamma comas, et circum tempora pafci. 


Nos pavidi trepidare metu, crinemque flagrantem 
Excutere, et fanétos reftinguere fontibus ignes. 


* From the Tran/atlions of ibe Eleétoral Academy of Sciences at. Maz 
beim, Vol. VI. 
* ZEncid, Lib. II. v. 582. 
Vou. V. B Tl. We 


b) Odfervations on Animal Ele&ricity. 

If. We are informed by Dionyfius and other writers, that 
fire ftreamed forth from the hair of Servius Tullius, the 
Roman king, during fleep, when he was about feven years 
of age *, 

. IIL. Pliny alfo fpeaks of light often fhining around the 
heads of men:—Hominum guoque capita vefpertinis boris 
flella magno prefagio circumfulgent t. 

IV. We are told of a Carmelite monk, who was always 
attended with this phenomenon, that, as oft as he ftroked 
his hair backwards, it emitted {parks {. 

V. A woman at Caumont exhibited a phenomenon of the 
like kind, as her hair, when combed in the dark, always 
emitted fire §. 

VI. Father J. Faber fpeaks of a young woman from whofe 
head {parks of fire always fell when fhe combed her hair |]. 

VII. Francifeus Guidus produced bright flames from his 
body when he rubbed his arm with his hand as he lay in 
bed 4. 

VIII. Ezekiel de Caftro **, a phyfician of Verona, relates 
the following circumf{tance refpecting Caffandra Buri, a lady 
of the fame place :—As often as fhe touched her body, even 

“ina flight manner, with a linen cloth, it emitted fparks in 
great abundance, which could be perceived by every perfon 
ftanding near her, and which were attended with a confider- 
able noife. Her maids were often deceived by this pheno- 
menon, and believed that they had, through carecleffnefs, 
dropped fome coals between the fheets, as fhe always caufed 
her bed to be warmed in winter, at which time the {parks 
were moft abundant and ftrongeft. 

IX. Anthony Cianfi, a bookfeller at Pifa, when he pulled 
off a narrow fhirt, and a piece of cloth which he wore on his 
breaft, emitted {parks from his back and arms, with a crack- 


* Antig. Rom. Lib, IV, 

+ Hift. Nat, Lib. IL. cap. xxxvii. 

+ Cardaous, Lib. VILI. de rerum variet. cap. xliii. 

§ Scaliger. Exer. 374. 

}j In his Palladium Chymicum, 

q Bartholinus de luce animalium, Lugd. Bat. 1647, p. 12% 
** In his book De iene lambentes 


“ 


Obfervations on Animal Elefricity. 3 


Iing noife, to the great terror of his whole family. Fortu- 
nius Licetus was a witnefs of this phenomenon *. 

X. “ Among us,” fays Gefner, ‘* where heated ehatinens 
are ufual, it aften happens that many perfons, when they 
have warmed themfelves at a ftove, and then pull off their 
fhirt in a cold bed-chamber, or move or fhake it after it is 
pulled off, obferve crackling flames to burft from it ¢.”” 

_ XI. Bartholinus fays, that a rope-dancer at Turin, ac- 
cording to the teftimony of a refpeCtable man, Caffiano a 
Paro emitted a like phenomenon of light from his body f. 

XII. The fame author fays, that oe proceed from the 
fkins of cats, and particularly from the back; which can be 
clearly perceived by ftroking the hair backwards even with 
the leaft preflure, and Eipecially after they have been warmed 
at the fire §. 

XIII. Scaliger fpeaks of a white Calabrian horfe, which, 
when combed in the dark, emitted {parks of fire |j. 

XIV. Ezekiel de Caftro fays{, of another horfe of the 
_ fame kind, that real {parks were obferved when his neck was 
ftroked upwards with the hand or a currycomb, 

XV. Simpfon treats of the light emitted by the bodies of 
animals when rubbed; and quotes inftances of fuch pheno- 
mena on combing the hair of a woman, curry ing a horfe, 
and. ftroking a cat with the hand **, 

XVI. The following circumftance refpe@ting himfelf was 
told by Vaudania to the celebrated Beccaria :—** For ten or 
twelve days paft, fince the cold fet in, I wear, between two 
fhirts, a piece of beaver’s fkin. Always when I pull off my 
upper fhirt at night, I obferve that it adheres, in fome de- 
gree, to the piece of fkin; and when I draw my fhirt from 
it, I fee {parks which have a ftriking refemblance to thofe of 
electricity. Scarcely do I begin to pull off the piece of fkin 


* Licetus de cauffis monftyorum, Lib. II. cap, xxviii. 
+ Lib. de lunariis, 

+ De luce animali, p. 123. 

§ Ibid, p. 189. 

|| Exercitat. 174, 

qj Liber de igne Jamb, 

** Diff. Phyf, de fermentatione, 1676, 


B2 when 


4 Obfervations on Antmal Eleétricity. 
when I find that it adheres, and with ftill greater force, to 
the under-fhirt. On taking it out I obferve, when I hold it 
in the right hand, that the frill of my fhirt moves up from 
my body towards it. If I remove the piece of fkin to a 
greater diftance, and draw it from the frill, the latter moves 
again towards my body. If I bring the piece of fkin nearer, 
the fhirt moves again towards it. This ofcillation of my 
fhirt between my body and the piece of fkin continues al- 
ternately, till it is gradually leffened, and at length ceafes.”’ 
XVII. About twelve years ago the following cireumftance 
was communicated to our Academy, in writing, from Ber- 
digheim :—On the 12th of February a young woman having 
put on an aired fhift, which was exceedingly narrow and fat 
very clofe to her body, heard, on laying hold of it, a crack- 
ling noife like what oftimes proceeds from the flame of a 
candle, and obferved fparks to iffue from all thofe places 
which fhe touched with her hands. Being aftonifhed at this 
phenomenon, fhe called to another girl, who flept in the 
next apartment, to come to her affiftance, as her fhift, which 
fhe in the mean time pulled off, was on fire. They both 
now fhook the fhift in order to extinguifh the fparks; but 
the more they moved it, the effects were ftronger: on ex- 
amining the fhift, however, no traces of fire could be difco- 
vered. The firfl maid then put on another fhift, which fhe 
took from her box; but as foon as fhe touched it, the fame 
crackling noife and appearance of {parks took place. She 
then put on her dirty fmock, which fhe had before pulled off, 
and returned to'bed,. on which the phenomenon difappeared. 
Some perfons to whom the circumftance was afterwards re- 
lated, were defirous to know whether the fame phenomena 
would again appear if the maid put on another clean fhift. 
She did fo the following night; and as often as the {mock 
was touched by her or any other perfon, a crackling noife 
was heard, and fparks were emitted every time the finger 
was brought near it. The {peftators now defired her to put 
on anaes clean fmock, which belonged to another maid: 
on approaching the hand a like naile was heard, and the 
appearance of fire was obferved; but no {parks iffued from 
her body, even though touched, when fhe had the fhift on. . 
An 


Objervations on Animal Eleétricity, $ 


An experiment was then made to try whether the fame phe- 
nomena. would occur if another woman put on the girl’s 
fhift; but nothing of the kind was obferved either by the 
perfon who had put it on, or by thofe who touched it; but 
the phenomena were repeated when it touched the maid 
on whom they had been firft obferved. Every time after this 
period that the fame perfon put on a clean fmock, the fame 
effects were produced; but they difappeared after the fhift 
had been worn fome days. On the 1ft of February the 
whole phenomenon ceafed, and after that time never re- 
turned. 

XVIII. M. Flad junior, member of our Society, having 
been in a confumptive ftate about eight years ago, obferved, 
for a long time, as often as he pulled off or drew on his 
ftockings, that {parks proceeded from his feet in abundance. 
Having afterwards recovered his ftrength in fome meafure, 
the {parks difappeared; but they returned when his ftrength 
again began to decreafe, and continued till his diforder put 
an end to his exiftence. 

XIX. As often as M. Hertel, chaplain to the Elector, 
draws his hand over his breaft, which is covered with hair, 
abundance of {parks are feen in the dark. 

XX. I was told by Count von Kagenek, that it often 
happened to him, that when he drew a filk handkerchief. 
between his fingers, while ftanding near a ftove, long lumi- 
nous ftripes were here and there obferved. 

XXI. Iwas told alfo by a lady named Von Fraife, that very 
often, when fhe rubbed her hands or arms even weakly with 
a linen cloth, lying in bed, abundance of {parks iffued from. 
them. 

XXII. M. Von Schlemmer, of Deux-Ponts, relates of a 
lady named Von Koch, that fhe often obferves, when the 
gets up carly, ‘that a ribbon, with which fhe binds up her 
hair during the night, adheres io her fingers when fhe pulls 
it off, and moves with velocity towards other neighbouring 
bodies. Having, by my defire, applied to the ribbon a piece 
of fealing wax, which had been rubbed, it was always re- 
pelled by it. 

NII, Tam acquainted with another lady, whofe hair, 

when 


& Odfervations on Animal Eleéricity. 


when conibed in the dark, always has a luminous appear- 
ance, as I have fometimes obferved myfelf. 

- XXIV. I have a white horfe, from the body of which, 
particularly im the winter-time, the comb brings forth abun- 
dance of fparks. T have likewife a white dog, from the back 
ef which, when I draw my hand over it, m @ warm room, 
from the tail to the head, {parks iffue with a {napping noife, 
and which feem fo troublefome to the animal, that he en- 
deavours to run away, I have fometimes charged a jar with 
thenr. 

XXV. I have often produced the fame phenomenon on 
an afhi-grey, firong, lively cat. 

XXVI. We are acquainted with three kinds of fifh which, 
when touched, give a fhock almoft like that occafioned by a 
charged jar, viz. the cramp-ray, Raia torpedo L.; the elec- 
trical eel, Gymnotus eleétricus L.; and the Szlurus elefiricus L. 
The more modern philofophers have convinced themfelves, 
by repeated experiments, that the effects of tlre fhock given 
by thefe animals are of an eletric nature, though to me it 
2ppears probable that they depend, in part, on another caufe. 

The animal electricity which I have announced in thefe 
mumerous infiances is of the coarfer kind, and may be eafily 
obferved by every one; but there is another kind, of a more 
delicate nature, which does not fpontaneoufly manifeft itfelf, 
but mutt be concentrated and called forth by art. This 
finer electricity I find firf{ mentioned in a letter of M. de 
Sauffure to the editor of the Jovrnal de Phyfique at Paris. 
The experiments which this celebrated philofopher made, 
partly on himfelf and’ partly on others, by means of Volta’s 
electrometer and condenfer, are given there only in extracts ; 
but the confequences he deduces from them are as follows: 

' In order to produce this eleétricity, bedily motion is ne- 
ecfary. The electricity thence produced arifes from the fric- 
tion of the body avain& the clothes; for as often as he made 
the experiment naked, he found no electricity. In order 
that electricity may‘be produced by the friction of the body 
againft the clothes, the latter nmft poffefs the natural warmth 
of the body; for when he had on clothes that were cold, he 
could never percetye the leaf trace of electricity: no elec- 

tricity 


On the Method of Difiilling in fome Parts of India. 9 


tricity appears alfo when the body is in a flate of perfpira- 
tion. There are perfons who, in this manner, never emit 
eleGtricity. The electricity which fhews itfelf in the human 
body is pofitive, and fometimes negative. The caufe of this 
variation he was not:able to difcover. 

[ To be concluded in next Number. ] 


II. On the Method of Difiilling as pra€tifed by the Natives 
at Chatra in Ramgur, and other Parts of India, By 
ARCHIBALD Keir, E/g.* 


Ap body of the ftill they ufe is a common, large, un- 
glazed, earthen water-jar, nearly globular, of about twenty- 
five inches diameter at the wideft part of it, and twenty-two 
inches deep to the neck, which neck rifes two inches more, 
and is eleven inches wide in the opening. Such, at leaft, 
was the fize of the one I meafured ; which they filled about 
a half with fomented Mahwah flowers, that fwam in the 
liquor to be diftilled. 

The jar they placed in a furnace, not the moft artificial, 
thongh feemingly not ill adapted to give a great heat with 
but very little fuel. This they made by digging a round 
hole in the ground, about twenty inches wide, and full three 
feet deep; cutting an opening in the front, flopmg down to 
the bottom, on the fides perpendicular, of about nine inches 
wide and fifteen long, reckoning from the circle where 
the jar was to come, to ferve to throw in the wood at, and™ 
for a paflaze to the air. On the fide too they cut another 
{mall opening of about four inches by three; the jar, when 
placed, forming one fide cf it, to ferve as a chimney for the 
{moke to go out at. The bottom of the earth was rounded 
up like a cup. Having then placed the jar in this, as far as 
it would go down, they covered it above, all round, with 
clay, except at the two openings, till within about a fifth of 
its height; when their furnace was completed. mah hg 

In this way I reckon there was a full third of the furfice 


af ‘| * Fromthe Afiatic Refearches. ae 


* 


of 


8 On the Method of Difiilling ut Chatre | 


of the body of the ftill, or jar, expofed to the flame, whett 
the fire came to be lighted; and its bottom, not reaching to 


within two feet of where the fuel was, left a capacious hollow 


between them, whence the wood, ‘that was fhort ‘and dry, 
when lighted, being moftly converted into flame, -and cir- 
culating on fo great a furface of ‘the ftill, gave a much 
ftronger heat than could elfe have been produced from fo 
very little fuel / a confideration well worth the attention of a 
manufacturer, in our country more efpecially, where firing 
is fo dear. There indeed, and particularly as coal is ufed, it 
would be better, no doubt, to have a erate; and that the air 
fhould enter from below. As to the benefit refulting from 
the body of the ftill being of earthen-ware, I am not quite 
fo clear in it. Yet, as lighter fubftances are well known to 
tran{mit heat more gradually and flowly than the more folid, 
fuch as metals, may not earthen veffels, on this account, be 
lefs apt to burn their contents, fo as to communicate an em- 
pyreumatic tafte and fmell to the liquor that is diftilled, fo 
often, and fo juftly complained of with us? At any rate, 
in this country, where pots are made fo cheap, I fhould 
think them greatly preferable, as at leaft much lefs expenfive 
than thofe which the gentlemen engaged in this manufac- 
ture moft commonly employ: though of this they are beft 
able to judge. 

Having thus made their furnace, wid placed the body of 
the ftill in it, as above defcribed, they then luted on, with 
moiftened clay, to its neck, at the opening, what they here 
call an adkur; forming with it, at once, a cover for the body 
of the ftill, with a fuitable perforation in it to let the vapour 
rife through, and the under-part of the alembick. The adkur 
was made with two earthen pans, having round holes in 
their middles of about four inches diameter; and, their bot- 
toms being turned oppofite the one to the other, they were 
cemented together with clay; forming a neck of jun@ion 
thus of about three inches, with the fmall rifine on the 
upper pan. The Jowermoft of thefe was more fhallow, and 
about eleven inches wide, fo as to cover exaGtly the opening 
at the neck of the jar, to which they luted it on with clay. 
The upper and oppefite of thefe was about four inches deep, 

9 and 


and other Parts of adi, 9 


and eee inches wide, with a ledge round its perforation 
in the middle, rifing, as is already faid, from the i inner fide 
of the neck, of about half. an inch high, by’ which a gutter 
.was formed to colle¢t «the Boadentod’ Cane as it fell down; 
and from this there was a hole in the pan to let it run of 
by; to which hole they occafionally luted on a fmall hollow 
bamboo, of about two feet and a half in length, to convey it 
to the receiver below. The upper pan had Ala another hole 
In it, of about an inch fquare, at near a quarter of its cir- 
cumference from the one below juft {poken of, that ferved to 
Jet off the water employed in cooling; as fhall be mentioned 
prefently. 
_ Their adkur being thus fitted to the jar, they completed 
the alembic by taking a copper pot, fuch as we ufe in our 
kitchens, of about five inches deep, eight wide at the mouth, 
and ten at the bottom, which was rather flattith; and turn- 
ing its mouth downward, over the opening in the adkur, 
luted it down on the infide of the jar with clay. 

For their cooler they raifed a feat, clofe upon, and at the 
back part of the futnace, about a foot higher than the bottom 
of the copper pot. On this they placed a two or three gallon 
pot, with a round hcle, of about half an inch, in the fide of its 
and to this hole, before they lighted their fire, they luted on 
a fhort tube of a hke bore; pace the pot, and direéting its 
fpout, fo as that, when filled with water, it threw a conftant 
and uniform fiream of it from about a foot high, or near the 
centre of the bottom of the copper pot, where it was diffufed, 
pretty porep ctely. over its whole furface; and the water 
falling down into the upper part of the pan of the adkur, it 
thence was conveyed, through the fquare hole already men- 
tioned, by a trough luted on to it for that purpofe, to a cool- 
ing teceiver a few feet from the furnace; from which they 
took it up again, to fupply the upper pot as occafion required. 

As their ftock of water, however, in this fort of circula- 
tion, was much {maller than it feemingly ought to have been, 
being fearcely more than fix or eight gallons, it too foon be- 
came hot; yet, in f{pite of this difadvantage, that fo eafily 
might hate been remedied, and the fhortnefs of the con- 
ducting tube, which had nothing but the common air to 
» ¥OL, V. Cc cool 


cool it, there ran a ftream of liquor from the. ftill, and but 
very little vapour rifing from it, beyond any thing I had ever 
feen from ftills of a much larger fize, fitted ‘with a worm and 
cooler. In about three Lone time, indeed, from their light- 
ing of the fire, they drew off full gree bottles of tpinit; 
which is more by a great deal, I believe, than could have 
been done in our way from a {till of twice the dimenfions. 

The conveniences of a worm and cooler, which are no 
{mall expence either, I have myfelf often experienced; and 
if thefe could be avoided in fo fimple a way that might eafily 
be improved, the hints that are here offered may be of fome 
ufe. The thin metal head is certainly well adapted, I think, 
to tranfmit the heat to the water, which is conftantly re- 
new ed; and which, if cold, as it ought to be, muft abforb 
the faftett poflible: whereas, in our way, the water being 
confined in a tub, that, from the nature of its porous fub- 
ftance, in a great degree, rather retains than lets the heats 
pafs away, it foon accumulates in it, and becomes very hot ; 
and, though renewed pretty often, never anfwers the purpofe 
of cooling the vapour in the worm fo expeditioufly and ef- 
feftually as is done by their more fimple and lefs expenfive 
apparatus. In this country, more efpecially, where labour 
and earthen-wares are fo cheap, for as many rupees, and 
lefs, twenty furnaces, with ftills, and every thing belonging 
to them, independent of the copper pots, might very well 
be erected, that would yicld above a hundred gallons of {pi- 
rits a-day; allowing each flill to be worked only twice. So. 
very cheap indeed is arrack here, to the great comfort of my 
miners, and of many thoughtlefs people befide, that for one 
fingle peyfw (not two farthings fterling) they can get a whole 

cutcha-[ecr of it in the ba/ar, or above a full Englifh pint, 
and enough to make them completely intoxicated ; objects 
often cantal to be feen. 

Of the fuperior excellence of metal in giving out heat from 
itfelf, and from: vapour contained in it, we have a very clear 
proof in what is daily performed on the cylinder of the fteam- 
engine : for, cold water bemg thrown on it when loaded, the 
containcd vapour is conftantly condenfed; whence, on a 
vacuum being thus formed, and the weight of the atmo- 


{phere 


10 On the Method of Difiilling at Chatra oe 
| 


and other Parts of India. Ib 


fphere acting on the furface of the pifton attached to the arm 
of the balance, it is made to defeend, and to raife the other 
arm that is fixed to the pump; while this, being fomewhat 
heavier, immediately finks again, which carries up the pif- 
ton, while the cylinder is again filled; and thus, by alter- 
nately cooling and filling it, is the machine kept in motion ; 
the power exerted in raifing the pump-arm being always in 
proportion to the diaweter of the cylinder, or to the furface 
of the pifton, which is cxaétly fitted to it, and on which the 
preffure acts. 

The contrivance, too, of having the under part of the 
alembic, where the condenfed vapour is collected, or upper 
part of what they call the adkwr, of earthen-ware, of fo great 
a-thicknefs, and of courfe at fo great a diftance from the heat 
in the body of the fiill, is well imagined to keep the fpirits 
the cooleft poffible, when colleSted, and running off. 

By thus cooling and condenfing the vapour, likewife, fo 
fuddenly as it rifes, there is, in a great meafure, a conftant 
yacuum made, or as much as poffible can be; but, that both 
fleam rifes fafter, and that water boils with much lefs heat 
when the preflure is taken away from its furface, is an axiom 
in chemiftry too well known to need any iluftration ; it 
boiling in vacuum when the heat is only uinety or ninety- 
five by Farenheit’s thermometer; whereas in the open air, 
under the preflure of the atmofphere, it requires no lefs than 
that of two hundred and twelve, ere it can be brought to the 
boiling point. 

I muf further obferve, that the fuperior excellence of con- 
denfing the vapour fo effeCtually and {peedily in the alembic 
to our method of doing it in a worm and cooler, is greatly 
on the fide of the former; both from the reafons I have al- 
ready adduced, and becaufe of the {mall fiream of vapour 
that can be only forced into the worm, where it is condenfed 
gradually as it defcends ; but, above all, from the nature of 
yapour itfelf, with refpect to the heat contained in it, which 
of late has been proved, by the very ingenious Doctor Black, 
to be greater by far than, before his difcoveries, was ima- 

ined. For vapour he has fhewn to be in the fate of a new 
“fluid, where water is diffolved by heat; with the aififiance, 
9 Cz perhaps, 


— On the Method of Dijfiilling at Chatra 


perhaps, if I may be allowed a conjeéture, of the air which 
it contains; and all fluids, as he has clearly demonftrated, 
on their becoming fuch, abforb a certain quantity of heat, 
which becomes what he very properly calls latent heat; it 
being heat not appearing either to the fenfes or to the ther- 
mometer while they remain in that liquid ftate, but fhowing 
itfelf immediately by its effects on whatever is near It; upon 
their changing their form from fluid to folid, as on water 
becoming ice, or metals fixing, and the like. In the folu- 
tion of falts, alfo, there is an ablerMign of heat, as we daily 
experience in the ooling of our liquors by diffolving falt- 
petre in water; and this he has found to be the cae with 
water itfelf, and other-fluids, when paffing into a ftate of 
vapour by boiling. . From the moft accurate and judicious 
experiments, indeed, he infers, and with the greateit appear- 
ance of truth, that the heat thus concealed in vapour raifed 
by boiling, from any given bulk of water, would be fully 
fufficient, if colle&ted in a piece of iron of the like fize, to 
make it perfe&tly red hot. What then mutt be the effect of 
fo much heat communicated in our way of diftilling to the 
worm, and to the water in the tub, will be fufficiently evi- 
dent, from what has been faid, to prove, I think, that we 
have hitherto employed a worfe and more defeétive method 
than we might have done with refpeét to ccoling at leaft, 
both in the making of fpirits, and in other diftillations of the 
like kind, where a PGnitar mode is adopted. 

The poor ignorant‘Indian, indeed, while he with wonder 
furveys the vaft apparatus of European difiillers, in their 
immenfe large ftills, worms, tubs, and expenfive furnaces, 
and finds that fpirits thus made by them are more valued, 
and fel] much dearer than his own, may very naturally con- 
clude, and will have his competitors joim with him in opi- 
nion; that this muft alone furely be owing to their better 
and more judicious manner of diftilling with all thofe inge- 
nious and expenfive contrivances, which he can no ways 
emulate: but in this, it would appear, they are both equally 
mittaken ; imputing the effeGts, which need not be contro- 
troverted, perhaps, to a caufe from which they by no means 
proceed ; the fuperiority of their fpirits not at all arifing from 

the 


and other Parts of India. "yg 
the fuperior excellence of thefe ftills and furnaces, nor from 
their better mode of conducting the diftillation in any re- 
fpect; but chiefly rather from es greater fkill and care in 
the right choice and proper management of the materials 
they Papier in fermentation; and, above all, as I appre- 
hend, from the vaft convenience ‘they have in cafks, by 
which, and from their abilities in point of ftock, they are 
enabled, and do in fact, in general, keep their {pirits for a 
certain time, whence they are mellowed, and improved fur- 
prifingly both in tafte and falubrity. 

All I need further add with refpe& to diftillation, and on 
the fuperior advantages in the mode of conducting it here, to 
that we have been in ufe to, employ, for the raifing of {pirits, 
fimple waters, and the like, is only to obferve, I have no fort 
of doubt but that the intelligent chemical operators at home, 


if ever they fhould get a hint_of it, will make no mauner of 


feruple to ufe it alfo, and to improve upon it greatly by a 
few ingenious contrivances, which their knowledge and ex- 
perience will fo eafily fuggeft. The principles on which it 
feems founded, indeed, binecrally with regard to their way 
of cooling, are fo ftriking and juft, that in many other di- 
fiillations befides, thofe of fpirits and waters, they may be 
employed, I apprehend, with very great profit and advan~ 
tage. I fhall now, however, confine myfelf to mention only 
the benefit that may refult from a like procefs in the raifing 
of the finer aromatics, while the heat contrived, as in our 
way, befides impeding the diftillation, muft, from its long 
action on fuch fubtile bodies, probably injure them greatly 
in the effential quality on which their excellence depends ; 
and upon this very account Iam apt to imagine that the 
greater quantity obtained, and the fuperior quality of the oil 
of rofes made in this country, to that made from roles with 
us, is owing chiefly, if not entirely, to their better and more 
judicious manner of extracting it here. For with us, the 
ftill, being made of metal, may, in the firft inflance, impart 
too great and too fudden a degree of heat; and next, the 
oil continuing fo long in the vapour, and that much com- 
prefled, may, in fo delicate a fubjecét, not only entirely 
almofi unite it with the water, fo as to render the fepara- 

tion 


14 On the Method employed at Fex and Tetuan 


tion impracticable, but may at the fame-time alter its 
effence fo completely, as that it can no longer appear in 
the ftate it otherwife might have been found in, had the 
operation been better conduéted, or in the way they do 
here. A very few trials, however, would much better cer- 
tify this than all I can pofibly fay on the fubjeét, or, in 
fact, than all the reafoning 1 in the world. Therefore, as to 
my own particular opinion of the flavour and quality of the 
’ rofes at home being equal, if not fuperior, to that of thofe in 
this country, I may be entirely filent; the rules and reafon~ 
ing in chemiftry, though ferving gr die to enlarge and in- 
prove our underitanding, being what of themfelves can never 
be depended upon till confirmed by faéts and experiments ; 
where many things often turn out very different from what, 

from our beft and moft plaufible arguments, we had fie 
greateft reafon to expect. Or, if it fhould be found to be 
really true, what I have often heard afferted, by thofe how- 
ever who had it only from others, but not of their own par- 
ticular knowledge, that, in diftilling their oil of rofes at the 
places where they make it the beft, they ufe alfo with their 
rofes, fandal wood, and fome other aromatics, no rofes what- 
foever, it is plain, could ever of themfelves be made to afford 
a like oil, nor without fuch an addition as they employ. A 
circumftance, by the bye, that might poffibly eafily be cer- 
tified by fome one of the many ingenious corre{pondents of 
the Society who may happen to refide where it is made; and 
a knowledge of the real truth of it would certainly be of ufe. 


HI. On the Method employed at Fex and Tetuan to prepare 
thofe Goat Skins called Morocco. By C. A, Brow $sO- 
NET =, 


f RE fkins, after being flayed from the animals by ftrip- 
ping them off entire, are-immerfed in water for three days: 
they are then expofed to the air, and, when dry, the hair is 
taken off, but imperfe&tly. They are then dipped in flacked 
‘time, and {prinkled over with powdered lime to detach the 


* From the Bulletin des Sciences, No, 23. 


7 fmaller 


to prepare Morocco Leather, . 45 


fmaller hairs; after which they are wafhed in running water, 
and rinfed with care. After remaining a night in the water, 
they are dried in the open air. Thirty parts of thefe tkins 
are then placed in two quintals of bran, (each part confifts 
of fix fkins, and the quintal is 150 pounds.) They are fuf- 
fered to continue in this ftace, tuming them every day, till 
they have acquired a great degree of pliability. They are af- 
terwards wafhed again in running water, and trod upon with 
the feet; then thrown into a fecond bath made with white 
figs, about a quintal and a quarter of which are employed 
for thirty parts of {kins. The figs render the water fapona- 
ceous. They are left in this bath four or five days, during 
which they are often turned; and, while immerfed in the 
water, they are for three days befprinkled with finely pounded 
rock-falt. The water is then drained off, and, being again 
befprinkled with falt, they are placed in a heap in a flat vef- 
fel, where they imbibe the falt completely. The water they 
contain is wrung out by twifting them; and they then be- 
come exceedingly pliable, and fit for receiving the colour. 

If deftined to be red, half a pound of cochineal and three 
ounces of alum are employed for ten parts of fkins. They 
are then put into pits, where tan-beds are formed of about 
fifty pounds for each fkin; which is turned in fuch a man- 
mer that the grain is infide, and that the fkin may be filled 
with the tanning water. At the end of eight days they are 
turned infide out, and are ftill filled with the tanning water, 
in which they are left for fix days; care being taken to flir 
them, They,are then rinfed in running water; {eraped with 
an iron inftrument; cut up along the belly; and foftened 
with a litile oil. They are dried in the fun, and then cooled 
in the fhade: after which they are gently befprinkled with 
water, and the edges are paired off with three different in- 
ftruments of iron. When the red is too dark, a decoétion of 
a plant called razoul al achbi, a kind of annual mefembrian- 
themuim, is employed ‘to weaken it. This liquid is applied 
warm, by pouring a {poonful over each fkin, 

If the morocco is intended to be yellow, the fkins are pre- 
pared as for the red, but not falted till they. are put into the 
fig-bath ; and for five dozen of fkins, twenty-five pounds of 

tan 


16 Recipe for de Piyang Caterpillars. 


tan only are employed. They are dyed with the palvened 
bark of the pomegranate tree and alum. 

The falfe red dye is communicated to fkins with Brazil 
wood and alum. Inftead of Brazil wood, fouab, a kind of 
galium or rubia (madder), brought in large quantities ree 
Morocco, is often employed. 


IV. Recipe for deftroying Caterpillars on Goofeberry Bujhts”, 


A RECEIPT for this purpofe was offered to be commu- 
nicated to the Society by William Henderfon, of Baldridge 
Burn near Dunfermline, on the 6th of February 1795, for 
a fuitable reward. The propofal was referred to a Sub-Com- 
mittee, of which Dr. Monro, Profefflor of Anatomy in the 
Univerfity of Edinburgh, was chairman, who, after making 
trial of the receipt, gave in their report on the rft of July 1796. 
The receipt for the preparation, and the manner of ufing it, 
was in the following words :— 

Take one Scots pint of tobacco liquor f, which the ma- 
nufacturers of tobacco generally fell for deftroying bugs, and 
mix therewith about one ounce of alum; ant! when the alum 
is fufficiently diffolved, put this mixture into a plate, or other 
veffel, wide and long enough to admit of a brufh, like a 
weaver’s brufh, being dipped into it; and as early in the 
feafon as you can perceive the leaves of the bufhes to be in 
the leaft eaten, or the eggs upon the leaves, (which gene- 
tally happens about the end of May,) and which will be 
found in great numbers on the veins of the leaves on their 
under fide; you are then to take the preparation, or liquor, 
and after dipping the brufh into it, and holding the brufh 


* From Prize Effays and Tranfadtions of the Highland Society of Scot- 


land, Vol. I. 

+ Tobacco liquor is the fuperfluous moifture expreffed from ro!] tobacco 
in the operation of prefling it, and is, in fact, only a {trong infefion of 
tobacco in well or {pring water, which may be made, where it cannot be 
purchafed, by infufing any kind of tobacco in water till all the ftrength 
be extraéted. Perhaps the fulphat of iron (copperas), employed in dyeing 
the roll tobacco, contributes a little to the eficaey of the liquor: a little of 
it may therefore be added to the infufion. Enir, 

towards 


. 
| 
: 


Recipe for defireying Caterpillars. .- 17 
towards the under fide of the buth, which is to be raifed and 
Aupported by the hands of another perfon ;. and by drawing 
your hand gently over the hairs of the brufh, the abave li- 
quid is fprinkled and falls in fmall drops on the leaves: the 
confequence of which is, if the eggs are there, they never 
come forward; and if they have already generated worms, 
in a minute or two after the liquor touches them, they either 
die, or ficken fo as to. fall off the buth, at Jeaft they do fo upon 
giving it a little fhake. If, upon their thus falling off, they 
fhall not appear: to-be completely dead,, the buth fhould be 
held up, and either a little boiling water from a watering- 
pan thrown on them, or a bruife given them by a fpade or 
fhovel, or the earth where they lie turned over with a hoe, 
This preparation does not in the leaft injure the bufhes, 

The liquor here meant is generally not in the fame ftate it 
is extragted from the.tobacco, but is mixed by the tobacco 
ananufacturers with cold water, in the praportion of four or 
five pints of water to one of the original juice or effence. 
Therefore, any perfon; who may purchafe the juice itfelf, 
unmixed, muft mix it with water, in the abaye proportion, 
and the quantity of alum mutt be about an ounce for each 
Scots pint of the mixture. nes 

Dr. Monro’s report was in the following words :—I ob- 
ferved, along with Mr. Hamilton and Mr. Gordon,, (two 
other gentlemen of the committee,) and two gardeners wha 
were prefent, that fuch caterpillars as were wetted by the 
liquor Mr. Henderfon employs, , were killed in a very few 
minutes, and the experiment has been repeated by my own 
gardener with the fame effect. I have likewife found, that 
it kills a kind of green fly, which is yery hurtful to the 
leaves of plum-trees and other fruit-trees. . Jt has been 
very generally known, that the {moke and the juice of to- 
bacco weré pernicious to different. kinds of infects and 
worms; but it has not, fo far as I know, been employed in 
Mr. Henderfon’s manner; and as this has the advantage of 
not hurting the leaves, nor the fruit, I confider it as an uleful 
and material improvement, well entitled to a moderate 
premium. (Signed) Avux. Monro, M.D. 


Vou. V. D V. On 


58 On the biipey of ia igi ‘and Sout 
bits w, 10 3 brewed 


Vv. On. the gradual Changes in “Temperature and Soil With 
| take. place in different, Climates, with an Enquiry into the 
_, Caufe of thofe Changes. By the Abbe MANN. 


ai » [Gqngluded from Page 347 of the lait Volume. a 
II. Py Caufes of the gradual Alterations i in Soil’ and the 
Ree emporiature of ibe. Climate, pai: 


tre 4 


tee 


at HAVE no doubt that’ a great diester of different: Abie 
may ‘have contributed, ‘each its patt, more or lefs, to pro- 
duce thofe HEAR Hy Hiee are the object of the prefent re- 
fearch. Some Of thein are only accidental, and have taken 
place i in different countries at very &revent’ periods, while 
in others fome of them have not taken place at all. Among 
thefe are the draining of lakes and morafles, the extirpating 
of forefts, and the calli vation of land, All thefe cireum= 
flances, no doubt, ‘rendér the tempera: tire of climate milder. 
I found, however, one’ caufe, of a kind altogether different, 
which appears to me general and uniform in producing the 
above changes. “After what I have before faid, and in an- 
other place , it may be readily conjectured that I here fpeak 
of an union of the two diftiné principles, moifture and 
heat. Their niutual difengagement, and the increafe of the 
one above the other, afford, if I am not miftaken, a key t 
a true theory of the earth, 

~All the ancient writers who fpeak of the countries of Eu- 
rope beyond the latitude of 50° north, reprefent them as 
filled with Jakes and moraffes, and covered with immente 
forefts, almoft as America I$ at prefent. It is a certain fact, 
that the climate of North America is different from that of 
Europe by about ten degrees of pee eet ; oy the dif- 
trifts of North America lymg under 40° of nofth latitude 
are as cold and moift as the countries of Europe which lie 
in the latitude of 50°. New England lies between the 41ft 
and 46th deerees of latitude; yet it is obferved that the cli- 
mate there, in regard to heat and cold, is equal to that of 


* Sce my Muynoir on the Ancient State of Flanders in Memoires dé 


V Acad. de Bruxelies, Vol, 1. p. 6772 
the 


: 
| 
} 


aubich take, plage i in di ifferent Climates. 19 


‘the diftri@s of England between the latitude of 50 and 56. 
Tt is well known that the people of America are more Ba 
more extirpating the forefts, draining the marfhes, and cul- 
‘tivating the land; and that the etaate there is found to be- 
come perceptibly milder. Fora thoufand or two thoufand 
years paft the people in all the northern parts of Eutope 
haye been in the fame manner employed in the improve- 
ment of the foil. Thefe caufes, however accidental they 
may be, and however much dependant on human indutry, 
muft certainly have contributed their part to render the cli- 
mate milder, not only in the countries where they took place, 
but even in the neighbouring countries, expofed to the ef- 
feéts of their atmofphere. 
It is almoft needlefs to obferve, that the great riumber of 
Jakes and moraffes, which, according to the accounts of an- 
cient authors, exifted in ier time in the fouthern parts of 
Europe, muft have rendered the air of, thefe countries ex- 
ceedingly cold and moift as well as unhealthful, fince it Jef= 
fened its elaflicity, and filled it with thick vapours ; which 
correfponds with the defcription they have given us of them. 
The countries of Europe have not for a long time been feen 
coyered in that manner with lakes and morafles, if we ex- 
cept Sweden and Norway; though the places where fuch 
marthes formerly exifted, both in “England and on the Con-< 
tinent; in Gaul, Germany, and the European Sarmatia, 
may be ftill clearly obferved. It is certain that human in- 
duftry, i in the courfe of ages, has in part contributed to pro- 
duce this change, as a great many epochs are known when 
the draining of lakes and moraffes was undertaken ; but I 
have no souht that gradual finking of. the furface of the fea, 
which occafions a Ate and pradual efflux, that could be 
produced only by thefe means, may have contributed its 
part alfo. But, from whatever caufe thefe changes may have 
proceeded, it is certain that. they have contributed to leffen 

the moifture and cold of all the countries of Europe. 
_ We know that in the time of Julius Cfar, and even 
long after, almoft all Germany and Sarmatia were covered 
with immenfe foretts. The Hercynean foreft was fixty days 
journey in length, It began in Belgie Gaul near the fey 
D2 and 


36 On the Changes of Temperature and Soit 


and extended through Germany and Poland. England wad 
proportionally lefs abundant in forefts. Now it may be 
readily comprehended what extraordinary cold, what moift 
and unhealthful air muft have prevailed in the climate of 
thefe extenfive countries, as all the mountains and plains 
were covered with fuch immenfe woods, and as each valley 
almoft contained a lake or a marfh; and what wonderfut 
changes i in the temperature of thefe lands muft have been 
effected by the extirpation of thefe extenfive forefts, and by 
draining off the fiagnant waters. Large woods prevent the © 
heanis of the fun front penetrating to, and warming the foil 
they impede alfo the free diffufion of the internal heat, as 
the fallen leaves and branches which rot on the. ground form 
a moift crn{t through which the internal and external heat 
can with difficulty force a paffage. In the laft place, they 
concentrate the cold and moift vapours, render them putrid, 
and corrupt the whole atmofphere. This has been always 
obferved in North America, as we are affured by Dr. Wil- 
fiamfon; and the confequences are bilious and intermittent 
fevers in fummer and autumn, and inflammatory fevers in 
winter. He afferts, that the opener and drier the land bes 
comes, the more it is remarked that thefe fatal difeafes de- 
cereale, This muft have been the cafe formerly in Europe 
under the like circumftances, and the like caufes muft have 
contributed to render its climate milder and more falubrious. 
The Celts and Sarmatians, who were the firft inhabitants 
of all the European countries lying to the north of Italy and 
Greece, like all the barbarous nations under different names 
which defecnded from them, and which over-ran the Roman 
empire in the fifth and fixth centuries, defpifed agriculture, 
and cultivated no more land than was fufficient to fupply the 
wants of the current year. They lived chiefly either on what 
they caught tr hunting, or the flefh of: their domeftic ani« 
mals, of whieh they reared a great many; as they confidered, 
though very unjultly, thefe employments as much nobler 
than the cultivation of land. Now it is certain that the cul" 
ture of the earth, which breaks its furface, puts it in moves 
ment, keeps it in a flate of continual tendernefs, and makes 
it!capahle of imbibing the rays of the fun In fammer, and of 
affording 


which take place in different Climates. at 
#fording a paflage to the internal heat in winter; and by 
thefe means contributes to preferve a continual equilibrium 
of the principle of heat in the earth and the atmofphere. 
“The contrary takes place in all uncultivated countries, efpe-« 
sially when they are moift, and covered with wood. 

It can no longer be doubted that the gradual draining of 
the ftagnant water in all Celto-Scythia and European Sar- 
matia, with the extirpation of their large forefts, and the ge- 
néral cultivation’of the fields of thefe countries, muft have 
had an influence alfo on the atmofphere of Greece and Italy. 
Thofe cutting north-winds which converted every thing into 
ice, and of which the Greeks and the Romans complain fo 
much, have, in a great meafure, ceafed fince the principal 
caufes which produced them no longer exift. As long as 
Germany, Pannonia, Dacia, Mcefia and Thrace remained 
uncultivated and covered with immenfe forefts, their atmo- 
{phere was exceedingly cold, thick and heavy, and had a 
continual in@uence on that of Italy and Greece, in which, 
becaufe they were open and warm countries, the atmofphere 
was confequently far lighter. The exertions of this fluid to 
recover its equilibrium were the caufe of the cutting north 
winds, of which the Greeks and the Romans complained fo 
much. But after thofe centuries, when the whole of Celto- 
Scythia and Sarmatia became opener and better cultivated, 
their atmofpheres muft have come nearer to an equilibrium 
with that of Greece and Italy, and confequently thefe ftreams 
of air from the north muft have decreafed in the fame pro- 
portion. This muft have contributed to moderate the cli- 
mate of Greece and of Italy, and to render it much milder 
than it was about 1800 or 2000 years ago; and to fuch a 
degree, that, had there been no other caufe, we could no 
longer wonder at, or entertain any doubt of, the effects of the’ 
cold which the ancients remarked in their time, and which 
‘are not obferved at prefent. 
~ It is well known that the winds which traverfe the im- 
menfe cold regions of the Continent are always colder and 
More penetrating than thofe which blow from the fea, 
‘America extends a great way towards the north; and its 
Femote difiriéts, on account of the ice, fnow, and continual 


“* 


fogs 


7 


22 On the Changes of Temperature and Sait 


fogs which. prevail therey haye never been. explored, and 
therefore remain unknown. This immenfe country cer- 


tainly extends nearer the north pole than the Continent of . 


Europe and Afia, the boundaries of which ate pretty well 
known. This, without doubt, may be reckoned among the 
‘oaufes which render North America much colder than’ Eu- 
rope under the fame degrees of latitude, as I have already 
remarked. Hence it happens that the immenfe Continent 
of America, the farther it extends towards the north, is more 
filled with lakes and marfhes, which muft confequently add 
to the feverity of thetwinds that fiveep their furface. , 
It will perhaps be faid, that it appears to follow, from my 
pofitions, that the more the cold of winter decreafes, from 
the above cqufes, the heat of fummer ought to increafe in 
the fame proportion. In my opinion it can be proved by 
many monuments, hiftorical as well as phyfical, that the 
fum-total of the mean fummer heat is greater than it was 
formerly, and that it continually incre: Foss though this takes 
place imperceptibly, and cam be obferved only aie periods 
ef confiderable Jength, and by comparing the reipective de- 
grees of dutant epochs. On the other hand, in regard to 
the degree of the intenfity of that penetrating, concentrated, 
and {iifling heat which is experienced even in Lapland, I 
mut fay, that this kind of héat-i is lefened by all thofe caufes 
before enumerated which leffen the cald of winter. -I by na 
means afcribe contrary effets to the fame caufe. Weare 
taught by general experience, that the thinner, purer, and 
more ela(tic the air is, the lefs, in the fame proportion, is 
the intenfity of the fummer heat; and, on the contrary, the 
thicker the atmofphere is, and the more it is filled with {tag 
nant and concentrated vapours, the heat is more intenfe and 
the more ftifling. For this reafon it is always cooler on the 
fummits of high mountains, while a fiifling and infupport- 
able heat prevails ; in the neighbouring plains, efpecially when 
they are furrounded by Tat This is always obferved in 
the favannahs of America. Dr. Williamfon was convinced, 
by experiments and obfervation, of the truth of my affertions 
in regard to North America; and he remarks, that when 
this extenfive coumtry becomes entirely open, when, sits 
g woods 


oo 


: 
: 


which take place in diffrent Climates. a3 


woods are cut down and its plains cultivated, the feverity of 
the winter cold will not only decreafe, but the fiifling uns 
thealthful heat of the fummer will be moderated. The quan- 
tity of the’{now, ice, and moifture is already evidently lef- 
fened ; and many plants, which could not be cultivated there 
formerly, now thrive and fuceced. 

I now come to the laft and principal caufe of thefe changes, 
which aéts in a general and uniform manner in preducing 
thefe effects, as all the others are merely accidental, and de- 
end on human induftry, I here mala to fay, that the 
principle of heat, increafed continually in the courfe of time, 
fo as to overcome the oppofite principles of motiture and cold, 
rénders, by thefe means, the earth drier and fuller of ftones, - 
and confequently increafes the fum of the degree of heat. 
Without this principle, in my opinion, we can never find 
fufficient ‘grounds for the wonderful changes which have 
taken nee in the nature of the foil of all ee Jands which 
border on the Mediterranean fea, which formed the ancient 
empire of Rome from Syria to India, and which at. prefent 
have all become uncommonly fruitful, dry and ftony, as I 


have already remarked. The mere neglect of agriculture 


could never have produced thefe effets, and muft have been 
attended rather with-effects of a contrary nature *, 
‘VI. Agenda, 


* The author here fubjoins the different paffages of ancient authors al- 
luded to in the courfe of this paper; but as thefe would occupy too much 
room, we muft content ourfelves with giving only the references, whict 
will no doubt be acceptable to our learned.readers, who may be defirous 
of profecuting this fubject farther :—Herodotus (469 years before the birth 
of Chrift), Lib. LV. cap. 28, 29; M. Terentius Varro (72 years before 
9. C.), De re ruftica, Lib. I, cap.73 C. Jul. Cafar (52 years before 
§.C.), De bello Gallico, Lib. 1V. cap. 153 Virgil (50 years before J. C.), 
Georgie. Lib. IIT. v. 349-383; Georgic. LV. v. 125,135; Diodorus 
Siculus, (45 years before J,.C-), Biblioth. Hitt. Lib. V. cap..25; Ovid 
(to-years before J. C.), Trift. Lib. 111. Eleg. 1V.v. 48, 49. 513 Eleg. X; 


| Strabo (26 years after J. C.), Geograph, edir. Bafil, 1539, Lib. 1!. 


p. 67, 68. 107. 119, Lib. VIL. p. 297; Pomponius Mela (40 years after 
§.C.), De fitu orbis, Lib. Il. cap. 1. De S ythia Evropeea; cap. 2, De 
Dheacia; Lib. U1. cap ILL. De Germania; Columella (43 years after 
J.C), De re ruttica, edit. Sephani 1543, in prafen. 7,8. Lib. J. cap. a. 
p. tt, 125 L. Ann, Sencca (55 years after J. C.), De providentia, cap. 4. 
edit. Ludy. Bat, Tom. i. p. 7113 Petronius Arbiter (60 years after J.C.) 

Satya 


rw * 


Cue J 


= 


VI. Agenda, or a Collection of Objervations and Refearchaty 
the Refults of which mey ferve as the Foundation for & 
Theory of the Earth. By M. Dz SAUSSUBE, > 


[Continued from page 359 of the Jat Volume. ] 


CHAP. XXI. 
RefaroBig to be made in regard to the Loadfione, 


Wey, 


, : ) 

a; Tue theory of the loadftone ought to form a part of 
the theory of the earth, becaufe the phenomena which de- 
pend on it belong to the whole globe; and becaufe Halley, 
and after him other philofophers, have endeavoured to ex- 
plain the different phenomena of the magnet by fuppofing 
the earth to be hollow, and that it contains in its cavity one 
or more magnetic globes. 

2. In confidering the load{tone it ought firft to be exa- 
mined whether, in order to explain its phenomena, we 
ought, like Defcartes, to fuppofe a clofe fluid moving ina 
vortex around the magnet, and entering at one of its Bales 
and iffuing at the other; or, as M. /Epinus, a difcrete fluid, 
fufceptible of rarefaction and condenfation, which is rarefied 
in one of the poles and condenfed in the other; or, laflly, 


Satyr. p. 103 Pliny the elder (74 years after J.C.), Hitt. Nat. edit. Bafif 
1525, fol. Lib, LV. cap. 12.p. 6c; Papinius Statius (85 years after J.C.), 
Sylv. Lib. V. p.83. edit. Am/?, 16245; Tacitus (97 years afier J-C,), De 
moribus Germanorum, cap-2. 4.5; Pliny the younger (99 years after 
J. C.), in Panegyr.cap.12; Plutarch (101 years after J.C.); De fuviis, 
Tom. II. p. 1156. edit, Frankf. 1620, p. 949; L. A. Florus (102 years 
after J. C.), Lib. IV. cap. 12. edit, E/xev. 1610, p. 440; Appianus (130 
years after J], C.), Excerpta ex ejus Celticis a Valefio, p, 1220; Paufanias 
(174 years after J.C.), Arcad. cap. xvii. p, 634. edit. Leip 1696, fol.; 
Dio Caffius (238 years after J.C.), Hift. Lib, XLIX, p. 413. edite 
Hazov. 1606, fol.; Herodian (229 years after J. C.), Hift. edit. Uxron, 
Gr. & Lat. 1699.8- Lib. I. p. 12. Lib. VI. p. 2213 Juftin (250 years after 
J.C.), Hiftor, T. I. cap. ii. p. 25. edit. E/x. 1664; Ammianus Marcel- 
Jinus (370 years after J. C.), Lib, XIX. cap.113 Jorvandes (25 years 
after J. C.), De rebus Geticis, cap. liv. p. 693. edit. Am/ff. 16553 Xiphi- 
Jinus (1083 years after J.C.), in Epir. Dionis Caffii, Libs LAVIIL, 


p- 774) and Lib. LXXI. Ps SO4. 
as 


eee as 


7 


Hints for thé Formation of a Theory of the Earth. = 25 


as M. Prevoilt *, two fluids, fufceptible of being combined 

- ywith, each other in fuch a manner that one of them alone is 

accumulated around the north pole of a magnet, while the 

other is accumulated around the fouth pole; and that all the 

. Magnetic phenomena may be explained by the eleétive at- 

tractions which thefe fluids exercife either upon each other 
or on iron t, 

3. It muft then be examined, whether the direGtion of the 
magnetic needle, and its inclination, depend on the fituation 
of a Jarge magnet enclofed in the bowels of the earth, as 
Halley fuppofes ; or on the action of one of thefe two mag- 
netic fluids towards one of the poles, and, perhaps, of the 
other fluid towards the oppofite pole, as M. Prevoft fuppofes. 

4. If we admit the hypothefis of a large magnet fulpended 
within the cavity of the earth, fhall we fuppofe, as the in- 
yentor of this hypothefis, that this magnet has four poles ? 
Or, fhall we endeavour to explain the whole, as that great 
geometer Euler has done, by a magnet having only two 
poles? Or, laftly, fhall we fuppofe, as Mr. Churchman, an 
American philofopher, has lately done, that the earth con- 
tains two magnetic poles, one at the north and the other at 


* De Vorigine des forces magnétiques, 8. Geneve 17838. 

4+ The celebrated Coulomb admits alfo two fluids, which compofe the 
magnetic fluid, and which exercife their aétion in the inverie ratio of the 
{quare of the diftance: but, in the theory of phenomena conncéied with 
the aétion of the globe, this philofopher fets out from certain faéts imme- 
diately given by obfervation; one of which it would be of importance to 
yerify in different points of the globe. This faét is, that the forces which 

 attra&t one of the poles of a magnetic needle freely fufpended towards the 
north, are equal to thofe which attraét the oppofire pole towards the fourth. 
Coulomb concludes that this equality exifts, becaufe a needle, weighed two 
different times, before and after it was magnetifed, was found exactly of 
the fame weight. 

C. Borda has found, by obfervations made firft at Breft, Cadiz, Tene- 
riffe, Goree on the coalt of Africa, and afterwards at Breft and Guada- 
loupe, that the intenfiry of the force exercifed by the globe on the mags 
netic needle, eftimated according to the number of efcillations made by 
the needle in a given time, was fenfibly the fame in thefe different places: 
This obfervation in other latitudes, efpecially on approaching the poles, 

might throw fome light on the theory of natural magnetifm,.—Nore of 
C. Wavy. : 
Wou. V. E the 


36 | Hints for the Formation of 
the fouth, at different diftances from the poles of the earthy 


which perform their revolutions in different times; and that, — 


from the combined influence of thefe two poles, we may 
conclude the annual changes of the declination with fo much 
precifion, that we can deduce the longitude of any place from 
its latitude, and wei the degree of foci ein which the 
needle experiences * 

5. Thus, by fappaliig one or more magnets in the inte- 
rior part of the earth, the annual changes of the declination 
and inclination may be explained by the rotary movements 
of thefe magnets. But in the fyftem, which does not admit 
thefe internal magnets, it is afked, Whether the changes of 
declination might not depend on movements which produce 
the change of obliquity, preceffion, nutation, and perhaps 
other phenomena or inequalities of that kind t. 

6. With regard to diurnal variations, an Englifh philo- 
fopher, Mr. Canton, confidering that it is proved by expe- 
rience that heat diminifhes the force of the magnet, thought 
that the folar rays, by heating the earth, muft leffen the at- 
tractive force of the grand magnet contained in it; and he 
thence deduced, as will be feen hereafter, an explanation of 
thefe variations. But Mr. Canton did not reflect on what 


* Heads of Leétures by S. Prieftley, London 1794. 

+ iEpinus gives another explanation independent of thefe movements. 
It may be poffible, according to this philofopher, that the declination of 
the magnetic needle arifes, in general, from the irregular figure of the 
nucleus of the magnetic globe,.or from an unequal diftribution of the 
fluid’in its interior part ; and to account for the variation of this declina- 
tion in one place, in the courfe of time we might fuppofe that the figure 
of the nucleus, or the diftribution of the fluid it contains, is itfelf vari- 
able. /Epinus prefumes alfo, that the action of the iron-mines difperfed 
throughout the bofom of the globe, may have an influence on the varia- 
tion in queftion; and may, perhaps, be the fole caufe of it, Tentamen 
sbeoriae eledir. et magnet. p. 268, 271, 334- 

This philofopher withes that men of fcience, who have an opportunity 
of being near a mine of loadftone, w ould determine, by obfervation, whe- 
ther the maffés of this mineral, before th vey are taken fom the bowels of 
the earth, have their poles difpofed, in regard to the poles of the world, 
hike thofe cf needles freely fufpended: and whether, in certain maffes, the 


poles are not in an inverfe dire€tion, of which he fhews the poffibility by” 


means of confequent points. Lid. p. 333.—Note of the fame. 
Was 


>| 


@ Theory of the Earth, — a9 


was clearly feen by M. Zpinus, that this magnet, if it-ex- 
ifts, is funk to too great a depth in the earth for the action 
of the felar rays, or at leaft the variations of that action, in 
the morning and evening, to be able to penetrate to it. We 
4 “may, however, apply to the ferruginous minerals, difperfed 
in abundanete over the furface of the earth, what Mr. Canton 
fuppofed, in regard to the grand magnet contained in its 
bofom; and then, if we admit that thefe minerals exercife 
any action on the magnetic needle, we cannot deny that the 
“heat, excited by the rays of the fun, may diminifh that ac- 
tion. From thefe principles it would follow, that in the 
morning, when the fun warms the furface of the ground fitu- 
ated to the eaft of the needle, the latter, being lefs ftrongly 
attracted towards that part, ought to decline towards the 
weft; and, for a contrary reafon, it muft in -the evening de- 
cline towards the’ eaft. But Mr. Canton proved, by a long 
feries of obfervations, that at London, at leaft, this is the 
ordinary courfe of the diurnal variations. 
7. But it willbe proper to examine whether this explana- 
tion, even thus corrected, does not contain a paralogifm ; 
and when the attraétive force of all the ferruginous particles, 
difperfed over the furface of the earth, to the eaft of the needle, 

is diminifhed equally and fimultaneoufly, the needle ought 
not to remain motionlefs; fince the diminution of the attrac- 
tion exercifed upon the fouth-pole of the needle, compenfates 
for the diminution of that exercifed upon the north-pole*, 


* Let © be the centre of fufpenfion of the needle N.S., and a, 4, c,d, 
the forces which attraét the needle in oppofite direc- 
_tions; for example, pieces of iron. The forces in 


and dconfpire to make the extremity N of the Eaft. 

needle move towards the weft; and theforces ata ..% i 
hea iabiat: hep et owe 

and ¢ con{pire in the like manner to make the fame 4 4 

exttemity proceed towards the eaft. When the needle Wer. 


Temains at reft, there is an equilibrium, and the 

forees a 4-¢ = 44d, But in this fuppofition, if 
the forces of the fame fide, 4 and c for example, gradually diminith, th 
equilibrium will not be interrupted. For, letS—=y + m andc=x +m: 
if the forces 4 and ¢ are eyually diminithed by the quantity , we fhall 
always havea+2—=6+4y. The cafe will be the fame with any aug 
Mentaiion, if it be equal and Gmultaneous on all the fides of the needle. 


*@—Nore of the Author, 
Es I fay 


28 — Hints for the Formation of a Theory of the Earth. os 


i fay the fame thing of thofe fituated to the weft. If this rea~ 
foning be juft, the needle ought not to vary by the action of 
the folar heat, but when this heat diminithes the magnetic 
foree of the ferruginous parts fituated to the north of the ~ 
needle, more than that of the parts fituated to the fouth, or | 

reciprocally. ‘* 7" 

-To determine this curious queftion, it would be lain 
to make choice of two oppofite coafts, and directed: almoft 
eaft and weft from the magnetic meridian; fuch as the coat - 
of Provence to the fouth, and that of Normandy to the north ; 
to eftablifh two compafies well fufpended, fuch as thofe of 
M. Conlomb, one*to the fouth, at Antibes for example, 
and the-other to the north, near Cape de La Hogue; and to 
fee whether their diurnal variations did not proceed in a con= 
trary direction: that is to fay, whether that at Antibes, 
having the continent to the north, and only fea to the fouth, 
Ww dull. not decline, in.the morning, towards the weft, as that 
of Mr. Canton did; and whether that of La Hogue, having 
the continent to the fouth and fez to the iH would not, 
at the fame ‘time, decline to the eaft. Myr. Canton, indeed; 
who made thefe obfervations at London, had, to the north 
of his magnetic horizon, the greater part of England and all 
Ireland; and thus he muft bave had the variation weft in 
the morning and eaft in the evening, as he oblerved it; for 
it is certain that the fea preferves the land, which it covers; 
from the a@ion of the fun; and that thus the attraction of 
that land ought not to vary by the heat which emanates 
from that luminary. 

By carefully repeating and varying thefe obfervations, in 
places chofen with difcernment, we fhall be able to decide 
whether the recular diurnal variation depends upon a general 
“caufe, the action of which, however, is fufceptible of being 
fufpended or difturbed by local caufes; or whether we are to 
Lelieve, on the contrary, as M. Van Swinden does, that the 
diurnal variation is not a cofmic phenomenon, or that it does 
not depend on a general caufe inherent in the globe, and 
which every where acts according to the fame law. 

gy. Is there properly any action of the maguetic fluid on 
“the electric fluid? or is there, between thefe two fluids, only 
a refemblance of properties, or in their manner of action? 

- : £0. Is 


On the Effeds produced on different Stones, &c. 29 


» to. Ts it well afcertained, as'M. Van Swinden thinks, that 
the aurora borealis ats on the magnetic needle; and can any 
idea be formed of the mode of this actioa? 
11. The fame queftion in regard to the zodiacal Hight 
12. In general, the theory of the magnet is {till fo foc froma 
perfection, even in that part which depeiids merely on-ob= 
fervation, that itis much to be wifhed that obfervers and 


~obfervations were multiplied, efpecially in what concerns 


\ 


the inclination of the needle... In:regard to: the declination 
and its variations, M. Van-Swinden has: given a noble ex+ 
ample of correctnefs, and of conftancy in obfervations, and 
in the art of claffing and compariag the refults: It would 
be of great benefit if this example were followed in different 
fituations and climates. It would be highly interefting, for 
infiance, to determine, with precifion, the zones of the earth 
where the declination is nothing, and where changes take 
place, and the fame for the cheek 

[ To be continued. } 


VII. On the Efizets produced on different Kinds of Stones by the 
Vapour of the Fluor Acid. By M. Kortum of Warfaw*. 


Pesine employed myfelf in engraving on glafs by 
means of the fluor acid, and having obferved that forae 
pieces of the glats I ufed were more fufceptible of being at- 
tacked by it than others, Lrefolved to try the effects of this 
acid on different kinds of vitreous flones. Conceiving that 
the fizures would be corroded with more neatnefs, the lefs the 
filiceous earth contained in the ftonss was mixed with fo- 
reign matter, I expofed.a very bright piece of rock-cryftal, 
from Swifferland, at a temperature of 18° Reaum. for twenty- 
four hours, to the vapour of the fluor acid; and found, con- 
trary to my expectation, that no impreflion was made upon 
it. I repeated the experiment, doub ling, the temperature 
and the time of expofure ; but the ‘fof did not Jofe any 
of its fpledor. It is well known that pure rock-cryftal 
* From /% oigt s Megazin fur den neuefen xufland der naturkunde, Vol. 1, 

Part 3. 
differs 


40 Ox the Effeéts produced on different Stones 

differs from the coloured kinds by this circumftance—that 
by expofure to heat,.the former undergoes no change, while 
the greater part of the latter do. It is equally well known 
that ‘the action of the fluor acid on glafs is increafed by heat. 

In order that I might begin a feries of comparative expe- 
riments in this ré{pe et, I expofed, for thirty-fix hours, at a 
temperature of 40°, a ruby, fapphire, leuco-fapphire, eme+ 
rald, Oriental garnet, amethyft, chryfolite, avanturine, gi- 
rafol, a Brafilian topaz burnt, a Saxon topaz raw, and an 
opal; but after being taken from the apparatus, they feemed 
as little injured as the pure tran{parent rock-cryftal of the 
firft experiment. 

The diamond, which by its combuftibility thews itfelf to 
be a peculiar genus, did not fuffer the leaft change after four 
days expofure to the vapour of the fluor acid; the apparatus 
being placed on a common German ftove. 

Polifhed granite, being expofed to the vapour for three 
days on a ftove as before, neither the quartz nor the mica 
feemed to have been attacked. The feld-fpar, however, at- 
tracted my attention; being opaque and, muddy, and co- 
vered with a white powder. TI therefore repeated the expe- 
riment on a thin fragment of feld-fpar of a reddifh colour, 
noting its weight, which was 38 grains; and found it to be 
2% grains lighter. The ftone had alio hecome whitith and 
friable at the furface, exactly as when in a natural flate of 
efforefcence. 

The different fpecies of flints, mixed with foreign earths, 
are more or lefs fufible. But as this difference is not exactly 
in proportion to the quantity of the earths mixed with them, 
the proper explanation of the phenomenon mutt be fought 
for in the different degrees of affinity which thefe kinds of 
earth have for caloric. 

Figures traced out on the following ftones through a co- 
vering of wax, after being expofed for twenty-four hours to 
the vapour of the fluor acid, the apparatus being placed on 
the ftove, were all found to be etched: Chryfopras, Hunga- 
rian opal, onyx, Perfian cornelian, agate, chalcedony, green 
Siberian jafper, common flint. On the chryfopras the cor- 
rofion was above half a line in depth. In thofe places the 

green. 


y 
By the Vapour of the Fluor Acid. gt 


green colour of the ftone had difappeared, and the cavities 
were filled with a white powder. The ftrokes of the figures 
were expreffed with the greateft fimenefs and regularity on 
the opal; and the lines, in the like manner, were filled 
with a white powder. The onyx exhibited the contours 
very clearly, and the etching was pretty deep: the powder 
with which they were filled was likewife white. On the 
cornelian the figure was in part etched, and filled with white 
powder; in part there was only a white efflorefcence, though 
fill compaé& and entire. The agate and. chalcedony were, 
on the other hand, corroded white, but very unequally: here 
and there cavities were formed, each of which was lined 
with a white compact fubftance. The green jafper-was cor- 
roded very unequally, but almoft to as great depth as the. 
chryfopras. Some parts which remained compaét, and which 
were only as it were eflorefced, had loft their green colour 
and become white. 

Flint. The uncovered part, of a bright brown and fome- 
what tranfparent fpecimen, had become totally white, but 
was neverthelefs compact. As I had covered the ftone with 
wax, leaving a fmall fpot bare, without delineating any re- 
gular figure, I obferved that the efflorefcence had begun at 
the edge of the wax, and proceeded thence to the centre in 
fuch a manner that the white contour thereby produced re- 
fembled an imperfeé figure of a fortification, while the 
inner {pace was only partially efflorefeed, and ftill grey, but 
interfperfed here and there with white points. To free the 
ftone from the wax, I wafhed it in fpirit of wine. The white 
firure then gradually difappeared: in half a minute nothing 
of it was to be feen; and the thin fragment feemed tranf- 
parent as in its native ftate. When it became dry, how-— 
ever, the opaque white figure again made its appearance, 
After moiftening and drying it feveral times in fucceffion 
the revival of the natural colour and opacity became always 
more perfeét, and the white efflorefcence remained vifible 
when wet. As all thefe effects were produced by water and 
other liquids as well as by fpirit of wine, as I afterwards re- 
marked on other {pecimens, thefe phenomena of the flint had 
a great fimilarity to the change produced in the colour of the 

opal, 


Py : 

32 On the Eiffects produced on different Stones 

‘ opal, and its becoming tranfparent in water. I found means 

- to ftop the action of the fluor acid on a cornelian and a dark 
vown jafper, at that flage of the procefs when the ftone was 

fill compact, and the colours only whitened. In water both 

thefe ones recovered their. natural colour, and when dry 

became again white. / 

E expoted another opaque and almoft black piece of flint, 
-with efflorefced white points, and the ufual white cruft, 
without any covering of wax, at the ufual ftove-heat of about 
36°, to the vapour of the fluor! acid for five days in my ap- 
peratus. At the end of that period it had loft almofi 1-8th 
of its weight; for it was reduced from 403 to gz grains, and 
was thoroughly white, fo that the found parts of the nucleus 
had entirely the appearance’ of the efflorefced cruft. Some 
parts were friable; and I at the fame time remarked that the 
parts. of the nucleus, already naturally eforefced, as well as the 
cruft, were much lefs aéted upon than the found black parts. 

It is found alfo, that in regard to the natural efflorefcence 
of flints, the efllorefced cruft ferves the found nucleus as 2 
cover to defend it, and, by theie means, retards the total de- 
compofition of the ftone. Some, from this cruft being formed 
of feemingly foreign materials, whieh is faractinues confi- 
dered as lime and famctinias: as clay, and which in common 
refembles both, have deduced.too much, in regard-to the 
formation of flints, when they explain the phenomenon 
by feparation and fuccefive hardening from one of thefe 
kinds of earth. To. judge from the above expernments, this 
eruft is not properly the matrix, but a refult from the de- 
compofition of the ftone itfelf. 

The efflorefeence of feld-{par inte a granite-like mixhare 
3s, with juttice, confidered as a very remarkable geological 
phenomenon, as.?t announces an endlefs. feries of the total 
decompofition of the prefent combinations. The fueceffive 
degrees of the decompofition, by means of thefe experiments, 
may be exhibited with a fmall and very fimple apparatus. 
Turmalin from the ifland of Ceylon, and Zillerthal in Tyrol, 

ween and black columnar {chorl, and olive-coloured horn. 
blende, after twenty-four hours expofure, had experienced yo 
change. ; 

; White 


- 


Cees Se ew ee nD 


+ 


by thé Vapour of the Fluor Acid. 33 


White Carara marble, in a temperature of 20°, loft, im 
twenty-four hours, -“, of its weight; but ftill the fhining 
furface of its eryftallifed texture was ditinguithable. Weak 
fulphureous acid diffolved one-fourth grain out of forty - 
five; while, of another fragment, of 18 grains, 14 grain 
-was diffolved in the fame time. Black marble fuffered 
no lofs, either in its colour or weight. Agate was not 
attacked. 

Lamellated tranfparent gypfum fell into white powder on 
the furface, after being expofed for a few hours in the appa- 
ratus to the common heat of the ftove, and the Jofs of its 
weight amounted to ,. This powder was not foluble in 
diluted nitrous acid. From this it appears that the vapour 
of the-fluor acid did not deftroy the combination of the cal- 
¢areous earth and the fulphureous acid, but only abftracted 
the gypfum from its water of cryftallifation. 

As the zeolite, among the filiceous ftones, contains the 
greateft quantity of the water of cryttallifation, as the gypfum 


does among the calcareous, I expofed 102 grains of ftriated . 


zeolite at the ftove temperature. In forty-eight hours I 
found its furface friable, and‘its weight only 854 grains; con- 
feyuently 4 lefs, When immerfed in water, and again dried, 


it had inereafed 2'.. It now weighed 88 grains, but did not | 


recover its fplendour. On the tin plate, to which the ftone 
had been faftened with wax, I obferved near the latter a white 
powder, which had the appearance of fomething volatilifed 
from the ftone. I poured over the frothy cake of {parry fluor 
powder and fulphurous -acid a little water, and, after fome 


hours, found the inner fides of the apparatus of tin ‘plate . 


covered with a beautiful filky fubftance, of the brightnefs of 
mother-of-pearl, which was perfedly like that of the zeolite 
jn its natural ftate. But as I afterwards remarked the fame 
appearance of a {plendour like that of mother-of-pearl, after 
expofing other fiones in the fame manner, it is not to be 
aferibed to the zeolite exclufively. On the contrary, I rather 
confider it as an imperfect calcmation of the tin; as, by a 
quicker difengagement of the fluor acid, it, or a mixture of 
it with fulphurous acid, may acquire the’ property of attack- 
yng tin. 
Barytes, of a fibrous texture, when expofed twenty-four 
Vou. Vv. F hor urs 


2 Sr 


34 On the Efjcéls produced on different Stones 


hours in the ftove-heat, remained unchanged, and had fuf> 
tained no lofs of its weight or its {plendour. 

That I might not leave magnefian {tone unexamined, I 
expofed, for forty -eight hours, at the ftove-heat, a thin plate 
of Venetian tale w cighing 124 grains. After the experiment 
it weighed only 81 grains, and had therefore decreafed in 
weight more than }: it had alfo fallen into a foft tender 
powder, which floated on water, and had the appearance of 
magnefia. I poured water on the refiduum in the appa- 
ratus, and found next day the fides incrufted with {mall 
cryftalline glittering flakes, adhering in detached maffes, 
which could not be wafhed of with diluted nitrous acid. 
Though thefe may ! have been real magnefian falt, they feem, 
‘however, to throw fome light on the cryttallifation of ftones. 
Bergman had before ae ed the filiceous cryftallifation 
formed in diluted fluor acid, which had ftood a long time 
at reft over powder of filex. 

Among the various hypothefes refpeéting the formation of 
granite, and ftones in general, that which fuppofes the an- 
cient ocean, fo much fool of by modern geologues, to 
have confifted of a fluid totally different from that of our 
fea-water, and of which the latter may be only the refiduum, 
is not the moft improbable. In my experiments, about 50 
grains of the powder of fparry fluor, mixed with as much 
concentrated fulphurous acid as was equal to the fpace oc- 
gupied by the powder, was put into a tin-plate box, and the 
latter into another of the content of about 20 fquare inches ; 
to the lid of which, of firong tin-plate, I fattened, with wax, 

he fpecimens to be tried, Pad fhut the whole fo as to be 
‘air-ti ight. After expofing various kinds of ftones for fourteen 
days i found the inner {mall veffel in part corroded, and on 
the exterior fides a moift, weakly-adhering falt, cryftallifed 
in a confiderable quantity, which at firtt | confidered as a 
mixture of iron and fluo-fulphat ef lead, tin being feldom 
worked pure, and the folder having begun to give way. It 
is, however, poflible that fome tin may have been diffolved 
by the two acids combined. I diffolved fome of this vitriol 
in diftilled water, and dropped into it fome fpiritous tinCture 
of galls. The liquor became of a beautiful indigo-blue co- 
jours inftead of black or purple as I expected; “and a very 


light 


by the Vapotir of thé Fluor Acid. 98 

light precipitate, of the fame colour, was depofited at the 
bottom. A folution of muriate of barytes being dropped 
into the blue liquor, gave a white precipitate, like regenerated 
barytic fpar, without changing the blue colour of the firft 
light precipitate, which remained like a flimy fub{tance float- 
ing on the other, nor the clear liquor: and the latter, after 
having ftood feveral years, appears as deep a blue ascan be pro- 
thiced | by ammonia from a folution of copper. The blue flime 
was found fit for a pigment, but far inferior to Pruffian blue. 

On this occafion I recollected the blue colour of lapis la- 
zuli, which Marggraf afcribes to iron, and in which Rin- 
mann found fluor acid. This ftone, after two days expofure, 
remained unattacked, and its colour unchanged. If, how- 
ever, it is clafled among the family of the zeolites, it is, at 
any rate, of a changed nature; for the latter are eafily acted 
upon by the vapour of fluor acid. 

According to Bergmann, filiceous earth is not foluble in 
pure poems acid gas; but it is obferved in common life, in 
places where ammoniacal gas as well as carbonic acid gas 
are difengaged in abundance; fuch as dunghills, gréen- 
houfes, prifons, cattle-fialls, aul foap manufactories, &c. 
that the glafs in the windows. becomes much fooner opaque 
than in apartments where that is not the cafe. The caufe of 
this is owing in part to a cruft of foreigh matter, and in part 
to actual Pee If it now be admitted that the carbonic 
acid gas has a confiderable fhare in producing the efloref- 
cence of the glafs‘In the above-mentioned places, we may 
affume this effet, under certain modifications, in regard to 
the natural eflorefeence of ftones; as it is not fo much a 
folution of the earthy bafes, as a feparation of the cryftalliné 
connection, 

Though analogical conclufioris from chemical refults are 
of little value, they have led me to the following conjeéture : 
As the fluor acid hitherto, at Jeaft as far as I know, has never 
yet been analyfed, and as its radical is unknown, I am cf 
opinion that, till fomething pofitive is learned, we may admit 
that fluor acid is not effentially different from carbonic acid 
but in the degree of oxygenation, and that they have both 
one radical, va. carbon. : 


Faq VII. 47 


[sge-q | = 


VIII. An Eajfy and Cheap Method of preparing Sal Aératus, 
(Carbonat of Pot-afh.)- By E. A. HoLryoKe, M.D. 
of Salem, Maffachu/fetts*. 


Sir Aératus, or the falt formed of vegetable alkali fatu- 
rated by fixed air (carbonic acid), is, on many accounts, fo 
ufeful, that a communication of an eafy method of preparing 
it at little or no expence may be beneficial. The following 
may therefore be acceptable, if it be not already commonly 
known. I have myfelf prepared this falt for ten or twelve 
years paft in this way, and it is now kept in our apothecaries 
fhops. 

Take a large wooden box t, bore eight or ten holes, half 
an inch in diameter, in the fide of it, juft below the lower 
edge of the cover, at nearly equal diftances all round; bore 
alfo as many holes in the’ circular bottom of the box, clofe 
to the edge of it: then take another box of the fame kind, 
but of a fmaller diameter by half or three quarters of an 
inch ; place this in the larger, and, to keep it fteady, thruft 
three or four wooden wedges between the two boxes. The 
two boxes ¢ being thus prepared, fill the inner one with the 
pureft falt of tartar, or clean well-calcined pearl-athes, or 
any clean pure fixed vegetable alkali: put its cover on the 
outer box, leaving the inner one uncovered ; fling this double 
box, thus filled, with’a cord, and fufpend it in a diftiller’s 
vat or ciftern, while the wafh is fermenting, a little above 
the liquor, or in an empty ciftern, if it has been much ufed, 
and {till retains the fixed air: let it remain in this fituation 
for fix weeks or two months, or longer if it is not wanted ; 
let it then be taken out, and the falt, now fully faturated with 
the acid, be expofed to the fun and air to dry. 

The falt thus. prepared does neither efflorefce nor deliquefce 


* From the American Medical Repofitory. 

+ I make ufe of a common cylindrical box, about nine or ten inches 
jn diameter, and between five and fix inches deep. 

{ The defign of the outer box is merely to prevent any Cuft or dirt 
from getting into the-falt, while the holes in it fuifer the fixed air to be 
frecly admitted. ‘ 

in 


4 


a 


| Method of preparing Sai A etatus. 38 


' 4 the open air, and, for all common purpofes, is, I believe, 


®qual to that prepared by cryftallifation. 

Note. The pearl-afhes had better be put into the box ia 
™moderate-fized lumps than in powder, that the air may have 
free accefs to it. 

But if any choofe to have this falt in its moft perfect form, 
jet him proceed in this manner : 

Diffolve as much of the clean vegetable alkali. in boilmeg 
rai or other pure water as poffible; filter the folution 
‘through paper, pour it into a jar of {tone or earthen-ware, | 
‘cover the veffel in fuch a manner as that the air may ‘have 
accefs to it, but fo as to exelude all duft or foreign matter 
Let it be hung by a cord in a fermenting vat, or ciftern, for 
‘a month or two, in which time a great many cryftals will be 
formed; from which the fuperfiuous liquor may be :poured 
off, and the falt dried in Hippocrates’ fleeve. The fuper- 
fluous liquor may be again faturated with more alkali, and 
again uxpofed tothe air in the ciftern, without any lofs.. This 
‘laft is, without doubt, the moft perfect mode of preparation, 
and I have fometimes made afe of it; but, as it is much 
more troublefome to make than the other, and as the other, 
‘for all medicinal susrdees is perhaps equal 'to'this, I have 
for the moft part mar loyed ‘it. 

This fait is much more tolerable to the palate, and may 
de taken in larger dofes than the naked alkali ; and as it is 

.decompounded by vegetable acids \as well as the mineral, it 
may be exhibited infiead of the alkali .in perhaps every cafe 
where the latter is proper, unlefs the fixed air is judged -im- 
»proper. 

It is much fuperior to common alkali in forming Riverius’s 
anti-emetic effervefcing draught, as it contains a iio larger 
"proportion of fixed air, (in which the principal virtue-of that 
medicine is fuppofed to refide) than the mildeft fixed alkali, 
and is at the fame time much more palatable. 

I commonly direét about 3 ii, or rather more, of this falt 
‘to be diffolved in 3 iii of fair water; a large fpoonful of this 
folution, added to the fame quantity of good vinegar, or 
Jemon-juice, at the inftant of {wallowing it, makes an agree- 


~~ -able dofe. But the tafte of this folution is fo mild, that, if 


: ro) the 


38 - Communication from Capel Laffit, E/q- 

the prefcriber choofes, a fpoonful of it may be fwallowed 
alone firft, and as much vegetable acid immediately upon it, 
in which cafe none of the gas will be loft. 

When acidity abounds in the firft paflages, a little of this 
falt added to any bifter infufion, or the dry falt added to 
powder of columbo, or ahy peptic powder, is an effectual 
antacid. 

In calculous cafes this falt is recommended by writers, 
particularly by the celebrated Dr. Cullen in his Materta 
Medica, Vol. II. ch. 13. as being an happy expedient for 
conveying larger quantities of alkali into the ftomach, than 
it can bear in its natural ftate. 

Hitherto the common mode of preparing the fat for this 
purpofe, I believe, has been by impregnating a folution or 
fixed alkali with fixed air, by means of Dr. Nooth’s ma- 
chine; but any one who has prepared the medicine in both 
ways, will readily give the moft decided preference to that 
above defcribed, on account both of eafe and cheapnefs. 

It is fearcely worth mentioning, that, for ceconomical pur- 
pofes, fuch as promoting fermentation in dough for bread 
or cakes, where pearl-afhes is commonly employed, the fal 
aératus is much to be preferred, on account of the much 
larger quantity of fixed air eliminated in the procefs. 


IX. Communication from Care. Lorrt, E/g. refpecting the 
late Meteor and the prefent Comet. 


To the Editor of the Philofophical Magazine. 
SIR, Trofton, near Bury, Suffolk: 


Obpservinc an account of the Meteor of Sunday 
Sept. 22, in p. 434 of your laft Number, I trouble you with 
an account of it as obferved here. 

I was looking on that evening for the comet, which I ex 
pected to have feen between the Northern Crowh and the 
conftellation of Hercules. . This being about half patt eight, 
my eye confequently was then direéted weftward. The fky was 
cloudy and mifty: yery few flars appeared. Suddenly my at= 

tention 


refpetting the late Metcor and prefent Osmet. 39 


tention was called off from its immediate objeé& by a moft 
vivid reflection of light from the clouds of that part of the fky; 
as if full day had fprung on me inftantaneoufly. I immedi- 
ately turned round to difcover whence it proceeded, and faw 
a moft luminous body, apparently equal (or larger) to the full 
moon when fhe appears greateft, but certainly very much 
brighter. It was of an exceedingly fplendid gold colour, 
and round, except to the welt, where it was of a {trong red, 
drawing off to purple, and its edge ill defined, and rather 
unequal. It was about 12 or 15° high, and almoft exactly 
in the meridian. It feemed nearly ftationary; but what 
little motion it had, tending to the horizon nearly at a right 
angle.. In about three or four feconds it difappeared, as if 
finking behind the clouds: I obferved no f{parkles, nor any 
luminous train left behind it, nor any explofion. It was 
feen by many at Bury, and was alfo feen at Norwich, and at 
Cromer on the coalt north-eaft of Norwich. Thirty-five 
minutes patt eight was the time I minuted of its appearance : 
but I had not then correéted my watch by an obfervation of 
the fun on the meridian, for many days preceding. It might 
be about eight or ten feconds (as [ did not find it immedi- 
ately, the reflection being very widely extended) between 
my firft being firuck with the refie¢ted light, and the difap- 
pearance of the meteor. Near Norwich tt was obferved to 
throw out red fparks, or globules, as in Kent ; and was no- 
ticed to be of a very white light: and the different colour 
of its light may be naturally referred to different ftates of 
combuftion, and partly to different firata of atmofphere 
through which it paffed. 

I do not at prefent learn it Kas been feen any where much 
weftward of the line which thefe feveral obfervations indi- 
cated. It feems to have been very low; and if more ob- 
fervations could be colleéted and compared, it would pro- 
bably be found to have a very confiderable parallax, and its 
altitude and magnitude might be determined, efpecially if 
obfervations.could be had eatt and weit of this line. But it 
does not feem to have been feen at London, Peterborough, 
Oxtord, or Lincoln; or even at Cambridge, though fo very 
little weft of the places where it was feen. Meth it was fcarcely 

ba poflible 


40 ” Defcription of « Blaft-Furnace ‘ 
poffible to have been not feen by any perfon who was oat, 
# within the limits of the fenfible horizon which cireunt- 
fcribed it. This feems a ftrong prefumption that it mult 
have been uncommonly low shileed Very few ftars bemgy =. 
then vifible, it was not eafy to come to much accuracy a& . 
to its apparent path. 

Meteors have abounded Jately. I faw two very brilliant, 
but fmall ones, in one night, and within three minutes of 
time of each other; one between the Northern Crown and ; 
Bootes, and the other between the Crown and Hercules. - 
Fhe former appeared about the fize and brightnefs of Venus. 
And on the 2d, at about twenty minutes paft ten, another, 
which wasin the field of my night-telefeope with the comet :; 
befide many fmaller, ufually ealled Jfbooting flars. 

The laft time the weather has permitted me to fee the 
comet, was October 4, at twenty-five minutes paft ten, to @ 
very few minutes of its fetting. I thought its nucleus very 
difcernible, and the extent. of its coma rather increafed. 
From its then appearance I fhould hope, if the weather fa- 
vours, it will be traced down to its node; which feems likely 
to be in 17 or 18 of Sagittarius ; and that it may {till be 
Vifible for a fortnight from this time. 

I remain yours fincerely, 
CAPEL LOFFT. 


P.S. It is worthy of inquiry and obfervation, whether 
nearly all the very Jarge meteors have not been feen in or 
neat the magnetic meridian, as an acute and attentive phi-. 
kofophical obferver thinks to be the fact. 


XK. Defeription of a Blaft-Purnece for [melting Iron from the 
Ore, with that Part of the Blowing-Macbine immediately 
connecied with it. By Mr. Davin MusuHer, of the 
Glyde Iron-Works. Communicated by the Author. 


¥ IGURE 1, (Plate I.) reprefents a blaft-furnace, with part 

ef the plowite Inaeinee: 
A, the regulating cylinder, gist fect diameter and eight 
feet 


-t 


fer Smeliing Iron from the Ore: 4t 


feet high: .—B, the floating pifton, loaded with weights pro- 
portionate to the power of the machinc.—C, the valye, by 
which the air is pafled from the pumping cylinder inte the 
regulator: its length 26 inches, and breadth 11 inches,— 
-D, the aperture by which the blatt is forced into the fur- 
nace. Diameter of this range of pipes 18 inches. The wider 
thefe pipes can with conveniency be ufed, the lefs is the 
friction, and the more powerful are the effets of the blaft. 
—E, the blowing or pumping cylinder, fix feet diameter, 
nine feet high : tparnal of the pifton in this cy linder from five 
to feven feet per ftroke.—F, the blowing pifton, and a view 
of one of the valves, of which there are fometimes two, and 
fometimes four, diftributed over the furface of the pifton. 
The area of each is. proportioned to the number of valves : 
commonly they are 12 416 inches:—G, a pile of folid {tone 
building, on w hich the regulating cylinder réfts, and to 
which the flanch and tilts of the blowing evlindel are at- 
tached.—H, the fafety -valve, or cock; by the fimple. turning 
of which the blatt may be admitted to, or fhut off from thie 
furnace, and pafled off to a collateral ube on the oeppofite 
fide.—I, the tuyere, by which the blaft enters the furnace. 
The end.of the tapered pipe, which approaches the tuyere, 
receives fmall pipes of various diameters, from two to three 
inches, called no/e-pipes. . Thefe are applied at pleafute, and 
as the ftrength and velocity of the blaft May tequire. —K, the 
bottom of the hearth, two feet f{yuare—L, the top of the 
hearth, two fect fix itiches fquare: KL, the height of the 
hearth fix feet fix itches. —L is alfo the bottom of the bothes, 
which here terminate of the fame fize as the tep of the 
hearth ; only the former ate round, and? the latter fquare.— 
M, the top of the bofhes, 12 feet nid lig and ¢ight feet of 
perpendicular height —N, the top of the furnace, at which 
the materials are, “cha ed; commonly three fect diameter. 
—MN, the internal cavity of the furnace from the : top of the 
bofthes upw ards, 30 feet high.—NK, total height of the inter- 
nal parts of the furnaces 44; feet. —OO, the lining. This.is 
done in the niceft.manner with fire-bricks made on purpole, 
13 inches long and three inehes thick.—PP, a vacancy which 
18 left all round the outfide of the firft lining, threé inches 
broad, arid which is beat full of coke-duft. This {pace is 
Vou, V. i alluw ed 


42 Defcription of a Blaft-Furnace, &eg 

allowed for any expanfion which might take place in confe~ 
juence of the fwellme of the materials by heat when de- 
fcending to the bottom of the furnace.—QQ, the fecond 
Nning, fimilar to the firft.—R, a caft iron lintel, on which 
the bottom of the arch is fupported.—RS, the rife of the 
arch.—ST, height of the arch; on the outfide 14 feet, and 
18 feet wide—VV, the extremes of the hearth, ten feet 
fquare. This and the bofh-ftones are always made from 2 
eoarfe oritted freeftone, whofe fracture prefents large rounded 
grains of quartz, connected by means of a cement lefs pure. 

Figure 2 reprefents the foundation of the furnace, and 2 
full view of the manner in which the falie bottom 1s con- 
firucted, 

AA, the bottom ftones of the hearth. B, ftratum of 
bedding fand. CC, paflages by which the vapour, which 
may be generated from the damps, are paffed off. DD, pil- 
Jars of brick. The letters in the horizontal view, of the fame 
firure, correfpond to fimilar letters in the dotted elevation. 

Fieure 3, AA, horizontal fection of the diameter of the 
bofhes, the ming and vacaney for ftuffmg at M. C, view 
of the top of the hearth at L. 

Vicure 4, vertical fide-fection of the hearth and bofhes ; 
fhewing the tymp and dam-ftones, and the tymp and dam- 
plates. a, the tymp-itone. 5, the tymp-plate, whieh is 
wedged firmly to the {tone, to keep it firm in cafe of fplitting 
by the great heat.—e, dam-ftone, which occupies the whole 
breadth of the bottom of the hearth, excepting about fix 
inches, which, when the farmace is at work, is filled every 
éaft with ftrong fand. This ftone is farmounted by an iron 
plate’ of confiderable thicknefs, and of @ peculiar fhape d, 
and from this calle¢ the dam-plate. The top of the dam- 
ftone and plate is two, three, or four inches under the leve} 
of the tuvere hole. The fpaee betwixt the bottom of the tymp 
and the dotted’line is alfo rammed full of ftrong fand, and 
fometimes fire-clay. This is called the tymp- flopping, and 
prevents any part of the blaft from being unnecellarily ex- 
pended. 

The fquare of the bafe of this blaft-furnace is 38 feet 


the extreme height from the falfe bottom to the top of the 


erater Is 55 feet. 


XI, Extreé 


—— 


eee ‘ 


{ 43°] 


XI. Extra& of a firfi Memsir to ferve as a Natural, Chee 
mical, and Medical Hiftory of Human Urine; with fome 
New Faéts on its Analyfis and Spontaneous Alieration. By 
C. Fourcroy aad VauaueE.in * 


is 

F HERE is no animal matter which has been fubjected 
to more examination than urine, and there is none which 
has furnifhed more difcoveries to chemifts. They have, 
however, confined themfelves chicfly to an examination of 
phofphats, which were for a long time called Fufible Salts. 
Margraff, Pott, Schloffer, Haupt, and Roueile the younger, 
were almoft exclufively occupied with them from the time of 
Boerhaave te Scheele. This great attention beftowed on 
phofphats arofe from the intereft infpired by the difcovery 
of the phofphorus of urine, and the ideas which the alche- 
mifts had propagated refpecting the fingular preperties of 
thefe falts. What phyficians have done in regard to human 
urine has fearcely had any relation to its. nature, and has 
fupplied too much to the ridiculous pretenfions of empiri- 
cifm. The difcoveries of Scheele put an end to the inco- 
herence between medical obfervations and the chemical la- 
bours on urine. When the acid, which forms the greater 
part of the urinary caleuli, or the uric avid, was difcov ered, 
as well as the acid phofphat of lime, the formation of thele 
calculi, like thofe of the depots of the precipitates of urine, 
became much eafier to be comprehended than before; and 
it then became poffible to eftablith between the medical ob- 
fervations on urine and its nature, better afcertained, that 
relation which ought conftaatly to have been the phy figian’s 
guide, fince by it rie he could be furnifhed with any exaét 
light. The ufeful inferences which our colleague Berthollet 
has drawn from the examination of urine, and from its na- 
ture, more or lefs acid, in gouty affections, are at prefent 
well known. 

A long feries of enieiteit, undertaken by C. Vauquelin 
and my‘elf, on animal matte:s in general, prefented to us 


* From the Aynales de Chintie, Noe 91. 


G2 Jorg 


£2 Extraé of Fourersy and Vauguelin's 

tone ago a number of new facts in regard to the urine of 
men and animals. Our new analyfis of -urinary caleuli in- 
duced us tq refume, in greater detail, an examination of hu- 
man urine, the natural ares of thefe concretions. The re- 
fult of our Jabour on this liquor we communicated to the 
Inftitute in the fitting of the rith of Frimaire this year; and 
J fhall here give a hart account of it, fufficient to make.it 
known, and to prove how much light may be thrown, by 
an analyfis of this kind, on the phy A nature of animals, 

I, In this memoir the fmel] of human urine Is fir(t cons 
fidered as a very difting and charaéteriftic property of this 
liquid. In urine well conftituted; and when it iffues fram 
the bladder, it is neither the odour of ammonia, nor of an 
acid, nor of the violet: it is evidently aromatic, and de- 
pends entirely on a matter peculiar to urine, which makes 
it to be what it js, and without which it would not be 
urine. 

II, The orange colour of urine is, no lefs than its odour, 
Fy property which exclufively belongs to it, and which is 
found in no other animal liquid. Being fufceptible of many 
fhades, and excecdingly varied degrees in its intenfity, as 
.was long ago obferved by Bellini, it is indebted for this va; 
ration to the very variable proportion in the effect of the 
water and the colouring matter, and the latter is the fame 
that gives to this lignid its aromatic odour. The darkeft 
eoloured urine, either naturally or by artificial evaporation, 
affumes all poffible thades, like thofe remarked under diffe- 
rent circumftances, by the addition of water only in various 
quantities. Thus the fmelling and colouring matter of urine 
i3 very foluble in water. 

Hf. The authors of the memoir, in treating of the acrid 
and ftrone tatte of human urine, remark tha it this acridity 
is not ferely that of the faline fubftances held in folution 
in this liquor, which only modify it, by giving it a faline 
tafte. The durable acridity of urine depends alfo on, the 
matter which produces its fmell and colour. It varies, 

therefore, like thefe two properties, which it follows in their 
intenfity or diminution, When phyfiologifts afcribed the 
dayour of uring to thefe falts, they did not ‘kaiow » or did not 


pay | 


Memoir on Human Urine. 45 


pay attention to the fmall quantity of them in proportion to 
the mafs of water in which they are diffolved. 

IV. The component materials of urine, the number of 
which is confiderable, re-aét on each other during the pro- 
refs of analyfing them. The falts contained in it are mo- 
dified, and change their nature: but the property, above all, 
of becoming alcalifed, or of forming, by its fpontaneous al- 
teration, ammonia and carbonic acid, (a property which is 
aleveloped in a few moments in an elevated temperature, and 
which has made it be confidered as the moft alcalefcent of 
all the animal humours,) is the fource of the moft fincular 
changes in its nature. Inftead of remaining acid, it then 
turns vegetable colours green; it produces an efiervefcence 
with acids when poured over it; it changes its colour; it 
aflumes a fetid ammoniacal fmell; it depofits precipitates 
and cryfiallifed falts which it did not contain. This altera- 
tion begins fometimes even in the reins, and carries with it 
a difpofition to form calculi, which it would not have formed 
without it. It depends entirely on the urimary matter, the 

aufe of its odour, its colour, and its favour, 

Y. It follows, from the preceding confideration, that the 
analyfis of urine, by the means at prefent employed, mutt 
haye given many uncertain refults ; and that many errors, in 
this refpect, mutt have been committed. The action of firr, 
which fo fpeedily and fo eafily alters the nature of bodics, 
changes both the proportions and the properties of its pro- 
ductons. Urine, therefore, muft be examined at the mo- 
ment when it iflues from the body; the component paris 
of it mutt, as much as poflible, be fought for without em- 
ploving fire; in examining it, re-agents ought to be ufed, 
which, as in the analys of mineral waters, may ferve to 
afcertain, at the moment of their mixture, the matters con- 
tained in that liquid. The phofphoric, the uric, and the 
muriatic acids, with lime and ammonia, have already been 
fhewn in it; but {cience is as yet far from being in that ad- 
vanced ftate as to poflefs the number of re-agents neceflary 
for this kind of analyfis, which {till requires many new tes 
fearches. 

V1. Our refearches on the means of analyfis, carried cine 

farthee 


46 Extraé of Fourcroy and Vauguelin’s 


farther than any before undertaken, have been attended with 
no other fuccefs than to enable us to compare the pheno- 
mena they exhibited with thofe of evaporation. Thus the 
tranfparency of turbid urine, and the concrete flakes preci- 
pitated during the evaporation of urine, have fhewn us that 
the cauftic alkalies, and the precipitate formed by the tanning 
principle in the liquid, belonged to the phofphat of lime and 
a gelatinous animal matter. We have learned, by the fame 
comparative procefs, that even a very gentle heat formed in 
urine ammonia, which fpeedily neutralifed its acidity: that 
its colour embrowned by evaporation, and its abundant cry{+ 
tallifation, on cooling, after it had*been brought to the con- 
fiftence of fyrup, depended on the concentration of the par- 
ticular matter, the common fource of its colour, odour, fa- 
your, and its other characteriftic properties: that the fetid 
garlic fmell, and the cryftalline form, were two of its moft 
prominent characters: and, in the laft place, that. as all 
urine evaporated in this manner forms itfelf into a mats, 
there ought to be found in this mafs the conftituent matters 
of urine, except the portion of ammonia formed and vola- 
tilifed by the evaporating heat. ‘This lamellated eryftalline 


mafs, treated with alcohol, was almoft entirely diffolved, and’ 


nothing remained but a little of the grey faline fubftance 
which the water feparated from the’ phofphat of foda and 
ammonia, and a little phofphat of lime and uric acid, info- 
luble in the liquid, but which was infulated from the calea- 
reous phofphat by the ley of cauftic alkali. Thefe falts, and 


this acid, made fome milliemes only of the weight of the , 


nrine; while the matter diffolved by the alcohol formed 
fome centiemes. The latter was compofed of a little muriat 
of ammonia, benzoic acid, and urinary matter more abun+ 
dant than all the reft, Such is the feries of our analytical 
procefles, analogous to thofe employed on the refidues of 
mineral waters, and by the help of which we have been 
able to feparate the conftituent matters of human urine more 
exactly than had been done before, 

VII. The diftillation of urine, though confidered as well 
known, prefented to us feveral remarkable facts. Ina very 
genile fand-bath, frefh urine giyes water yery ammoniacal 

and 


ince aa a eat ace oaieaet 


—_—w 


= 


ed 


See eee a 


Memoir on Human Urine. 4? 
aod eryfiallifed carbonat of ammonia long before it is dry: 
the laft portions of water obtained effervefce ftronely with 
acids, and become of a rofe-colour, not much fufceptible of 
changing in the open air. It arifes from the carbonat of 
ammonia which the liquid product contains; and urine has 
a fingular difpofition to form this falt in great abundance 
and with great eafe, as is proved by all the means of analyfis 
applied to it. The native acid of the urine is then faturated ; 
flakes of animal matter are depofited, as well as earthy phof- 
phats and the uric acid. All thefe phenomena continue until 
the predominance of the carbonat of ammonia, which is 
formed, becomes very manifeft. They take place at a con- 
tinued temperature of 60°. 

VIII. We never faw, with any exaétnefs, but three fa&ts 
in’ regard to the putrefaction, or fpontaneous and feptic de- 
compofition of urine, viz. the horrible fetor by which it is 
accompanied ; the formation of a great quantity of ammo- 
nia which characterifes it; and the abundance as well as 
eafy extraction of the fufible falts or alkaline phofphat which 
follows. C. Hallé has given an exceeding good defcription 
of the fucceflive alterations which urine, left to itfelf, expe- 
tiences, but he has not followed them in regard to the nature 
of their materials; the objeét of his refearch was only to de- 
fcribe the effects in their appearances. Urine contained in 
a clofe veffel becomes of a darker colour; turns brown, and 
even black; emits a fetid, ammoniacal odour; depofits firft 
a light cloud, which is gradually changed into mucous 
flakes more or Jefs coloured. There are formed at its fur- 
face, or on the blackened cruft by which it is covered, and 
on the fides of the vefiel which contains it, cryftals in needles 
or in regular prifms, or filky tufts. Urine is then ammoni- 
acal inftead of being acid. Diftilled te a half, it gives a great 
deal of the fetid carbonat of ammonia: being carried ftilf 
farther, fo as to beeome fyrupy, it furnifhes acetite of am- 
monia: the thick part gives, by the addition of acids, a fharp 
and acetous odour. This refiduum of urine, when putrid and 
evaporated, does not, by the addition of the concentrated 
nitric acid, prefent thofe white concrete and abundant cryf- 
tals which arife in frefh urine evaporated to the fame degree, 


and 


48 Extrad of Fourcroy and Vauguelin's 
vad which belong ‘to the urinary matter not changed. » It 


was this>matter itis experienced the greateit and .moft 
fingular change by putrefaction ; it was the focus and fubject 


of it; and it gave birth, above all, to the carbonat of ammo- | 


nia which replaced it, and to the acetous acid, which, as 
the phofphoric and the uric, is found faturated by this kind 
of alcali. It appears, therefore, that in order to procure 
more of the phofphat of ammonia, it is of advantage to em- 
ploy putrid urine. 

IX. An attentive and careful examination of the firft 
phenomena of the putrid decompofition cf human urine, pre+ 
fented to us refults as imterefting at leaft as that of urine en- 
tirely decompofed. Thefe refults are connected, above all, 


with the formation of urinary:caleuli, which were one of 


the mioft important objccts of our labour. We were defirous 
of adding to the w dl-known. fact of the exiftence of caleu- 
Jous matter in every kind of urine, anfwers to the followi ing: 


queflions of fo much importance :—W hy are thefe matters — 


more abundant? Why dees a difpofition to calculus exift in 


fome fubjeéts and not in all, though the urine of all contains. 


what may form them? Why are they formed fometimes 
frecdily, and fometimes flowly? What is the caufe of the 
fix-fold variety of the calculous matters, their mixture, and 
interruption? Though we were far from having found a 
folution to all thele gueltions, we have at any rate "been able 
to refolve fome. aS, 

The white prifmatic cryftals, which are depofted on the 
pellicles or the fides of veffels containing urine, do not fhew 
thenrfelves till the liquid becomes ammoniacal. “They increate 
im quantity and bulk for fix or eight days : they. are prifins 
of fix planes, with py ramids having fix faces, which are rea- 
dily difeoyered to he ammoniaco-magnefian phofphat, like 
that often found, under the fparry fori, at the furface of 
white calenli. This fale does not exift, or is not formed, but 
when there is an exeefs of ammonia in the urimary liquor. 
This ammonia, by faturatimg the free phofphorte acid, fepa-~ 

rates the gelatinous matter lich gives birth toa Taucous 
precipitate, and contlitutes with that acid, and by uniting 


itfclf to the phofphat of magnetia, the AMIIMOBLACO- -raagnefia nn 


8 phofphat, 


7 


Memoir on Human Uririé. 49 
phofphat, which depofits itfelf in cryftals. The uric acid is 
equally faturated, and prefents urate of ammonia; which 
fometimes depofits itfelf in the calculous matter with the 
triple phofphat jult mentioned. This triple phofphat fepa- 
rates itfelf in cryftals of the liquor only becaufe it is lefs fo- 
luble than the two infulated phofphats. This falt, therefore, 
which does not exift quite formed in the urine, is the pro- 
-duce of its ammoniacal alteration. 

As ammonia and the carbonic acid go on always in- 
creafing when the uri¢ and phofphoric acids and the phof- 
phat of magnhefia are faturated, there remains in the liquor 
carbonate of ammonia, which then renders fyrup of violets 
green, and effervefces with acids. The acetous acid, which 
is formed at the fame time, becomes faturated alfo with am- 
monia; fo that the urine contains, at the fame time, acetite 
and carbonate of ammonia. Thefe three fubitances, formed 
almoft at the fame time by the decompofition of the urine; 
ammonia, the phofphoric and the acetous acids, are the 
produce of the urinary matter, which ceafes to be found in 
that liquid when altered by putrefaction. 

X. This alteration of urine does not always take place in 
the fame manner, and its decompofition varies according to 
the diverfified nature of that liquor. Sometimes, in one in- 
dividual, avhen the urine commonly prefents the before- 
mentioned phenomena, the liquid, inftead of emitting an 
ammoniacal odour, becomes covered with a green and white 
mouldinefs, which increafes for fifteen or twenty days. In- 
ftead of containing ammonia naked, it contains the acid, and 
emits a fmell of it. This kind of urine is lefs fubjeét to al- 
teration than the preceding. It appears to be at leaft as 
common as that which alcalifes. Their difference depends 
evidently on the variation of their principles, and not on theit 
nature; for they are almoft always the fame, except in their 
proportion. Thus the urinary matter, the fource of the 
formation of ammonia, of the carbonic and acetous acids, 
and the caufe of the alterability of urine, does not produce 
or experience that alteration, or that decompofition, but fo 
far as it is mixed with a certain quantity of gelatinous mat- 
ter, which ferves it as a ferment. If it does not contain 

Vou. V, hi enough, 


Lx) Extra of Foureroy and Vauquelin’s 

enough, and if the urine, lefs gelatinous, is by thefe mean$ 
more coloured, has a ftronger fmell, and is more charged 
with urinary matter, it is lefs fufceptible of fermentation or 
putridity ; it preferves itfelf much longer and with its pri-~' 
mitive characters, and is more permanent: that, on the 
other hand, which is. lefs coloured, more changeable, and 
more difpofed to the formation of ammonia, depofits {fpeedily 
mucous flakes, and gives fooner a cloud and precipitate: It 
appeared to-us, that uriue lefs corruptible and lefs gelatinous, 
and in fome meafure more urinous, if I may be allowed the 
expreflion, was the fign of good health, and the produce of 
complete diveition ; while pale ure, more gelatinous and 
more decompofable, exilied mere particularly in weak fub- 
jects, and in cafes where the digettive faculties were leflened. 
There is reafon to believe that thefe two different ftates of 
urine, which exhibit it as two diftinct or different liquids, 
will one day furnith faéts of great utility to the healing art ; 
and that a folution of tan will fupply the means of diftin= 
guifhing them, and of determining their re'ation in regard 
to the nature and quantity of the precipitate which it will 
form in thefe liquids, compared i im different fubjects, or in. 
the fame at different periods. 

XI. Scheele firft announced the prefence of the: benzoic 
acid in the urine of man, and particularly in that of children. 
Rouelle the younger had before fulpeéted it in that of the 
mammefere, though he durf not give any opinion as to 
its nature. This acid is obtamed by fublimation, on heating 
the extract of urine in clofe veifels. It may be feparated till 
better by evaporating uriie>to the confiftence of clear: fyrap; 
and pouring on x the muriatic acid, by which it is preeipi- 
tated ; becaufé that acid deconrpoles the benzoat of ammos 
nia that has been formed. It ts by the latter procefs that we, 
have taucht the method of extracting it from the urine of 
horfes ie cows, and, above all, from the, water of dungs. 
hills, in fuficient abundance to fabfitute it m pharmacy. 
for that of benzoins In aword, this acid is the leaft abuns 
~ dant, and perhaps the moft variable of the matters in urine: 
It appeared to us tobe between ,.':, and 5.2.2: ) There 
are fome morbific circumftances under which ‘its quantity 

- increafes 


Memoir on Human Urine, Si 


increafes very fenfibly, and often very fpeedily. We bad no 
opportunity of determining the difference of the proportion 
in the urine of adults, or that of children, in which Scheele 
fays that it?s much more abundant. 

XII. The analyfis of urinary calculi, which firft directed 
our attention to urine as the fource of its concretions, jo- 
duced us to examine whether the oxalic acid exifted in this 
liquid. The oxalat of lime is, indeed, one of the mott fre- 
quent matters of calculi; and we have found it in the pro- 
portion of a fixth in the number of urinary {tones we exa- 
mined. None of the means which cam be employed to dif- 
cover the prefence of that acid, exhibited it to usin urine; 
while, on the other hand, the {fmalleft quantity of the oxalic 
acid, which we poured into the liquid, gave us an abundant 
and very heavy oxalat of lime; which proved to us, that fuch 
an acid could not remain diffolved in the urine. Thus, when 
a@ mural or mulberry-formed calculous, compofed of the 
oxalat of Jime.and an animal matter, by which it is agela- 
tinated,. arifes in the urinary duct, its production takes place 
even at the moment of the formation of the oxalic acid, 
This acid muft arife in the urine; and in that cafe there 
muft be in it an unnatural and morbific foreign production, 
There is reafon to believe that fome kinds of urine, which 
come from the body white and turbid, are charged with this 
falt; and that the oxalat of lime, formed by a caufe {tll un= 
known, iflues in this manner without producing calculi.” It) 
- may be thence feen of how much importance it is to make a 
chemical examination of the urine of difeafed perfons, and 
to eftablith a continued {eries of experiments on this fubject 
in fome hofpital fet apart for thefe ulcful refearches. 

The cafe is the fame with filiceous earth as with the oxalat 
of lime. We have never yet found it in urine, And its ex-. 
iftence in that liquid appears to be a rare cafe’ in pathology + 
of three hundred calculi, indeed, analyfed with care, two 
only were found centaining filex. . 

XIIJ.. This analyfis fhews that feveral matters, hitherto 
unknown in urine, exift in it, v2. 1, Phofpbat of magnefia, 
2. The urat of ammonia, which 1s formed at the time of the 
decompofition of the urine. 3. Albumen and gelatinous 

H 3 matter, 


52 Exirad of Fourcroy and Vauquelin’s 


matter. 4. The oxalic acid, which is produced under fome 
morbific circumftances. 5. Siliceous earth, which is found 
in it only very rarely. ‘Fhe four firft fubftances are conftant 
in it; the other two are only accidental, and therefore we 
pafs them over till after the examination of calculi arifing 
neceflarily from urine, and of which the conftituent matters 


have been diffolved in that liquid. Another new fact ob- 


tained by our labour is, that the particular matter which 
gives to urine its diftinguifhing characters, is converted, by 
means of the fermentation excited by the prefence of the ge- 
latinous body, into ammonia, carbonic acid, and acetous acid, 
and from thefe new products there arife in urine very re- 
markable changes. The analyfis of putrid urine differs, there- 
fore, very much from that of frefh urine. 

It refults from thefe refearches, by which human urine 
has become much better known than it was before, that it 
contains ten pr incipal or canftant fubftances, characterifed in 
the following manner ; 

A. Muriat of foda, which cryftallifes jn oCtaedra in eva- 
porated urine. 

B. Muriat of ammonia; the natural o¢taedral form of 
which is modified into a cube by its unjon with the parti- 
cular urinary matter like that of the preceding, and pafles 
through the fame combination from the cube ta the otta- 
edron, 

C. The acid phofphat of lime, forming about the 7ooth 
part of urine, confidered formerly as an earth, precipitating 
itfelf by the addition of alkalies, which take from it its excefs 
of acid ; carrying always with it a gelatinous matter which 
this acid held in folution, and rendering urine turbid at the 
moment when the ammonia is difengaged. 

D. Phofphat of magnefia, decompofed by alkalies, and 
giving its earth mixed with the phofphat of lime which is 
depofited ; becoming a triple falt, and feparating itfelf in 
cryftals by the fpontancous formation of ammonia. 

E, The phofphat of foda, efflorefcing in the air, and always 
united to the phofphat of ammonia. 

F. The phofphat of ammonia, little abundant when the urine 
is freth 5 increafing much by decompofition and the jorma; 

tion 


| 
} 
} 


Memoir on Human Urine. 53 
ion of ammonia, and giving only phofphorus when the” 
whole fufible falt of urine is heated with carbon. 

G. The uric acid, named yery improperly at firft the 
Jithie acid. It eryttallifes by the cooling of urine, and forms 
the red fand which that liquid depofits at the bottom of pots. 
It is more abundant in the urine of difeafed perfons. It may 
be diflolved exceedingly well by the cauftic alkali. 

H. The benzoic acid, more abundant in the urine of 
children; eafy to be obtained from urine evaporated to a 
dyrup; mixed to a tenth with concentrated fulphuric acid, 
and diftilled, 

I. Gelatinous matter and albumen, extremely variable iu 
its proportion inthe different kinds of urine; fhewing iticlf 
in clouds in urine where ammonia is formed, in filaments 
in that over which alkali is poured, in flakes by the evape- 
ration of urine; precipitating itfelf by the tanning principle, 
which. ferves to determiné the proportion ; occafioning a 
{peedy putrefaction of urine, which contains it in abun- 
dance ; appearing by their augmentation to be the firft canfe 
-of the formation of g¢alculi, and furnifhing them with the 
gluten which unites their molecule, and following, in their 
proportion, the energy or weaknefs of the digeftive forces of 
the diftribution of the chilous matter, 

K. The fpecial urinary matter, giving ta@urine its charac- 
teriflic properties really con{tituung it; giving it its odour, 
colour, and favour—its alterability into ammonia, the car- 
bonic and acetous acids, &e. It is the moft abundant of the 
matters contained:in urine; it forms alone the 4% of its 
‘mafters. It has been mproperly confidered by Rouelle the 
younger as a faponaceous extract. To it is owing the almott- 
total cryftallifation of urine evaporated to the confiltence of 

-fyrup; the folid and cryftalline form it aflumes in that {tate 
by the addition of concentrated nitric acid; the eryftallifation 
_ of the muriates of foda and ammonia modified, and im fome 
meafure reverfed—the former from the cube to the octaedron, 
and the Yecond from the o¢tacdron to the cube. This partis 
cular animal matter, which we call ur‘e, will form the qb- 
ject of another Memoir, deitined to ferve as.a fuppleanent d 
rs “ibe 


54 Fourcroy and Vaigquelin’s ‘Memoir on Human Urine. 
the prefent. It is of much importan¢e to animal phyficlogy 
and the art of healing. 

It appears‘that, befides thefe ten {ubflances, the real and 
conftant materials of human urine, it contains fametimes, 
but rarely and accidentally, fulphat of foda, muriat of pot- 
afh, fulphat of limé, oxalat of lime and of filex : that fome 
of thefe fubftances, and particularly the two latter, are only 
the-rare productions of fome particular and perhaps mor- 


bific difpofitions of urine. It will be of great utility to in- m 


quire into the circumftances which +have an influence on the 
exiflence of thefe’ matters, which are foreign’to the natural 
ftate. f 


XIV. In charaéterifing urine as a liquid very diftin& from _ 


all others, the matter which I have called wrée gives it, above 
all, the property of becoming, by the decompofition which 
it occafions, a liquor very different from what it was when 
it iffued from the bladder, and a fubftance totally new. Fer- 
mented urine is changed in almoft all its matters.’ The view 
of thefe changes, which terminates this Memoir, exhibits, as 
the moft ftriking refult, the production and exiftence in pu- 
trid urine of nine new matters, which do not exift in freth og 
natural urine. Lari 

1. Ammonia in excefs. 

a. The phofphioric acid faturated by this alkali. dé 

3. The phofphat of magnefia converted into ammontacde. 

magnefian phofphat. 

4. The urat of ammonia. 

5- The acetous acid united to ammonia. 

6. The benzoic acid faturated with the fame ammonia, 

+. The muriat of foda become oétacdral. ' 

8. The muriat of ammonia become cubic. 

9. The carbonat of ammonia. 

We may ftill add the precipitation of the albumen and 
gelatinous ‘matter eflected by the ammonia, and which ac- 
companies that of the phofphats; fo that thefe falts, like the 
matter of bone, are fufceptible of giving carbon when heated, 

Such is the general view of the facts contained in this firft 
Memoir,. They prove how many new and important refults 


a plo 


‘ 


- 


. 


e 
<¢ 


On the Combuftion of the Diamond. 55 
@ profound ftudy of urine may préfent to thofe who will be- 
ftow orf it that continued attention which it requires, and 
what influence fuch phenomena may have on the progrefs of 
enimal phyfiology. The authors promife to make known, in 
a fecond Memoir, all the properties which diftinguifh the 
particular matter that characterifes this liquid, which i is the 


moft abundant in it, and which they call urée, ‘as has been 
already faid. 


XIL. Evtrad from the Re; cport repetling Experiments made 
at the Polytechnic School in the Years V. and VI. on the 
- Combuftion of the Diamond. By C. Guyton *. 


asia the diamond is combuftible, is a truth’ which 


Newton, in fome meafure, conjectured; which experience 
has fully confirmed; and refpeéting which it is no longer 
poffible to entertain the leaft doubt. But what is the nature 
of this combuftibility ? My firft.experiments, publifhed in 
1785, on the entire combuftion in nitre in fufion ¢, feemed 


’ to announce that the diamond burnt in it after the manner 


of coal, fince it left an effervefcent alkali; and this fufpicion 
a¢quiyed more reality, after the examination made by La- - 
voifier of the gas remaining in the veflels in which it had 
burnt, and which he Sidad charged with carbonic acid. 
Mr: Tennant has finee furnifhed us with a new proof of 
this important fa&, by repeating the combutftion of the dia- 
mond by nitre in a gold crucible, as I had propofed, in order 
to obtain a refiduum abfolutely free from all foreign matter tf. 
There were, however, fill fufficient reafons to induce us 


‘to difbelieve that the diamond and carbon, or that the dia- 


mond and the carbon extracted from the carbonic acid by the 
noble experiment of Mr. Tennant, were thé fame fubftance. 
Independently of their external charaéters, fo completely 
different, feveral obfervations, which I have already commus 
Micated to the Inftitute, prove that their chemical characters 


* From the Annales de Chimie, No. 91. 
4 Opufeles de Bergman, French edition, Vol, XL. p. 124. 
$ Philofophical Tranfuctions 1797. 
eet ne 


"6 Experiments ‘ai at the Polytechnic School 


no leis excluded this identity. Tnideed if the diamond wat» 
pure carbon, why had it not the fame affinities?) Why does 
it not, like it, ferve to make the oxigenated muriat of pot- 
ath detonate; to deoxygenate fulphur, ‘arfenic, and phofpho= 
tus; to deoxydate metals, which are fufficiently fixed to un- 
deryo the degree of fire which determines its combination 
with oxygen? Why does it not form allo carbures? Why 
does it not, like it, conduct the electric fluid? , We know: 
that the aggre@ation conceals fometimes the affinities by 
eounterbalancing ‘their power, but not in operations where 
the bodies are fufliciently fixed, and the temperature fulfi- 
eiently high, to render effectual the weakeft attractions. 
Something remained, then, to be difcovered to harmomi{e . 
and make us comprehend facts in appearance fo. contrary *2 
i imagined that it was by attentive obfervation of what took  . 
place during the act of the combuftion. of the diamond, that 
we thould attempt to penetrate this fecret of nature. The 
experiments L am about to defcribe will, I hope, prove that 
my attempt has not been vain; that the explanation-of phe- 
nomena, which have appeared to us the mott incoherent, . , 
may hereafter be deduced from fome circumftances which: 
were not obferved nor even fufpected,.and which have en- 
abled us to.make an important {tep in the knowledge of the 
nature of the diamond, fince we can indicate fubftances 
which ap proach much nearer to it than carbon. | 
Thefe experiments, begun in Thermidor year 5} w ere not 
_ terminated till the 11th of Fruétidor year 6. Various acei- 
dents, which may be readily conceived, and the fewnels of 
the days wl:en the rays of the fun are not interrupted by 7 
clouds or weakened by vapours, were the prineipal caufes of 
this delay. I fhall fupprefs. the details of tho!e eflays which 
€id not lead to conclufive refults; but I fhall not: neglect 
thefe which furnifhed us with an opportunity of obferving 
feveral times the fame facts, and fometimes in a more defiinét 
manner; though, by the effect of fome unforefeen £ ireum-= 
fiance, it was not poffible to keep an account of “therm in 


* C. Berthollet, in his Le€tures at the Normal Schoo}, fill! leaves it im 
doubt whether the diamond is cryitallifed carbon, or carbon cambised with 


fomre oth.r fubfiance. e 
regard - 


- 


. 


- on the Combuftion of the Daetd: 54 


tegard to the correfpondence of the ingredients and the pro- 
ducts, I muft not omit to remark, that I had, as.co-opera- 
tors in thefe, experiments, C. bihaiies and Hachette. The 
journal of them was ¢orrectly kept by C. Deformes, formerly 
a pupil of the Polytechnic’School, and at prefent affiftant- 
preparer for one of the courfes of chemifiry. The moft im- 
portant phenomena were feen, at different fittings, by feveral 


men of letters. 


» The Couricit of the Adminiftration of the Polytechnie 
School, approving the objeé& of the experiments, authorifed 


me to difpofe of fomé of the diamonds in its cabinet *. 


The firlt experiment was made on the gth of Fructidor 
in the year,5. We placed upon the table of the mercurial, 
pneumatic tub, a bell of flint glafs 18-3 centimetres in di- 
ameter, and of the content of 5580 cubic centimetres. Near 
the tub was placed, on one fide, a pneumatic machine, to 
exhauft the common air from the bell by means of a bent 
tube, which rofe as far as the knob. .On the other fide was 
a water pneuthatic tub, bearing a large receivers having at 


* its tubulure a cock which bitainbinieated with the infide 


of the bell by a tube of bent elafs,, and rifing, in the like 
fhanner, to the hollow knob of the bell. On one of the 


edges of the mercurial tub was fixed a flide, bearing a kind. 


of mandril, deftined to receive a cylinder of hard wood move- 
able in eyery direétion; terminated by a handle of iron, and 
ferving to fupport a cup made of the crucible earth of Va- 
loone; {o that this cup could be cofveyed to every point of the 
interior part of the bell to prefent the diamond to the focus, 
This apparatus is reprefented by fig. 1. (Plate II.) Every 


thing being difpofed in this manner, we put into the eup 


’ 


: 
¥ 


4 


* The diamonds, whieh form -part of its collection of minerals, were 
found in an Englith fhip from Senegal, captured in the year 2. They 
were depofited at the Hotel det monnoies; where thy-remiined till the 
year 5, when, on the fuggeftion of our colleague Mongez, one of the ad- 
“niniftratays, the cvinider of the finances, after caufing it to be afcertained 
that the greater part of them were unfit for being cut, and for that reafon 
more valuable for inftruétion, ordered one third of thein to be given to 
“the Mufeum of Natural Hiftory, another to the Cabinet of the School of 
Mines, and another to that of the Polytechnic School. ‘The lot affigaed 


‘to the laft confitted of 26, weighing altogether 3-662 grammes, 


Vor. V. I an 


- 


38 Experiments made at the Polytechnic School 


- an incomplete o¢taedral diamond, having the edges a little 
rounded, of a dirty water inclining to yellowith-grey, and 
weighing exactly 142 milligrammes. On the cup, the edge 
of which was ground flat, a cover was applied, attached to a. 
thread tied round the lower part of the fupport. 

. The pump was made to aét till the mercury in the belt 
rofe within lefs than a millimetre of the orifice of the tubes 
of communication. The cock of the receiver of the hydto- 
pneumatic tub, which had been previoufly filled with oxygen 
gas obtained from the oxygenated muriat of pot-afh, was 
then opened; and the firft portion of this gas which had 
paffed into the bell was extracted by the pump, in order to 
exhanft as much as poffible the remainder of common air. 
After this it was filled with the fame gas to within 6g milli- 
metres of its internal edge, and 51 of the external. It may 
readily be conceived that ftill ‘a little air remained in the cup 
in which the diamond was, placed, and which, during thefe 
experiments, had been fhut by its cover; but its content 
not being altogether three cubic centimetres, this inconve- 
nience was thought the fmalleft of thofe which were to be 
apprehended. 

The diamond having been uncovered, we began, at ten 
minutes after one, to throw upon it the focus of the large 
lens belonging, to the cabinet of the Polytechnic School, the 
diameter of which is 40°59 centimetres, and the focus 135°3. 
We were well aware of the neceffity of heating the bell by 
degrees, to prevent its cracking. For this purpofe we inter 
pofed, at firt, green and blue coloured glafs; but whether 
they acquired more heat, or refifted dilatation more, thefe 
glaffes all fpecdily broke; and we were not able to accom- 
plith our obje& but by covering with paper, for fome mo- 
ments, the part of the bell which received the Juminous 
difk. When the paper was withdrawn, the mercury fell 
rapidly, 19 millimetres in the infide. The diamond, expofed 
to the focus for twenty minutes, did not inflame. It appeared 
at firft mealy, but fenfibly blackened at the furface when ob- 


feryed through the coloured glafs while expofed to the focus *. 
The 


* This carbonaceous colour had been be‘oze gbferved by Lavoifier in 
hs 


on the Combuffion of the Diamond, 89 


The focus having been intercepted by an opaque body to 
¢xamine more clofely the {tate of the diamond, no alteration 
was remarked in it, except that it had affumed a yellowifh 
Shade, perfectly like that of tranfparent amber. The atmo- 
{phere beginning to become charged with vapours, the expe- 
riment was difcontinued, in order that we might refume it at 
a more fayourable moment. This momeut occurred the next 
day the roth, and was announced by a rifing of the thermo- 
meters; one of which, expofed to the fun in-the open air, 
rofe to 40 degrees; and the other, expofed to the fun alfo 
under a bell-giafs to compare the interior temperature, rofe 
to 44 degrees. 

The focus was thrown upon the diamond at 28 minutes 
after rr. At 42 minutes after 11 the cone of light was in- 
tercepted, and we faw the diamond red, tranfparent, and fur- 
rounded with a faint radiation. When cooled, its edges ap- 
peared blunted: we obferved in it a black point; but it had 
become white, and had loft the yellow colour acquired the 
day before. 

The experiment could not be refumed till the 15th. We 
began, by noting the height of the interior column of the 
mercury, to calculate, according to the temperature and pref- 
fure, the volume of the aériform fluid remaining under the 
bell; and we judged that it had decreafed about 173 cubic 
centimetres. 

The rays of the fun were bright and ftrong; but the air fo 
much agitated, that while the thermometer under the bell 
was at 44°5, that expofed to the fun in the open air did not 
rife higher than 32°. There was a moment, however, when 
the Juminous cone produced a flight fcintillation on the fur- 

’ face of the diamond.. An opaque body, immediately inter- 
pofed, made it appear red ;_ but more obfcure than on the 
ioth. It was alfo found white after cooling. 

Being aftonifhed that the diamond, when inflamed, as on 
the roth, did not maintain of itfelf the temperature neceflary _ 
for its combuftion, efpecially in oxygen gas, as happens ta 


his experiments made on the diamond with the large lens of Trudaine, 
See Dict, de Chemie de l'Encyclop. Method. Voll. p» 741. 
a 1g metalli¢ 


60 Experiments made at the Polytechnic School 


metallic combuttibles*, we imagined it might refult from 
its being too much in a mafs, or perhaps alfo too much in- 
fulated from every other combuftible which might contribute 
to this temperature: and that we might make an attempt to 
remove this obftacle, we introduced into the fame porcelain 
cup, and without deranging the apparatus, a fmall cut dia- 
mond of the weight of eight milligrammes; but there was 
no appearance that the combuftion was in the leaft aug: 
mented ; and this fmall brilliant, inftead of being more ra- 
pidly attacked by the heat, after having been two days ex 
pofed to the action of the folar fire, capable of igniting ob- 
feurely the large diamond placed clofe to it, gave no figns of 
inflammation, and was taken from the apparatus without 
having experienced the flighteft alteration, either in the 
polith of its furface, or the vivacity of its edges. 

On the 23d of the fame month we took the diamonds 
from the faucer, to examine, with care, that which had given 
manifeit figns of a commencement of combuftion. It weighed 
no more than 88 milligrammes; it had therefore loft 54, 
about 0°38 of its weight. It {till retained its original o¢ta- 
edral form; but the angles were blunted, and the edges 
rounded. The furface was tarnifhed, and full of fmall inequa- 
lities; which, obferved with a magnifying glafs, prefented 
cavities, falient points, and fometimes parallel fections of the 
lamine. In feveral of the cavities we could plainly perceive 
a fort of {pecks inclining to grey ; but what appeared worthy 
of moft attention was, a pretty large hollow almoft at the ex- 
tremity of one of the quadrangular pyramids, which feemed 
to indicate the place where the folar focus had exercifed, at 
the end of the operation, its greateft intenfity; and where 
we diftinguifhed a blackith {tripe, not terminated like a ftroke 
formed by a foreign body, but on the contrary foftening it-. 
felf off, and penetrating into the interior part of the mafs by 
degrading its colour. 


* We had the more reafon to be furprifed at this phenomenon, as M. - 
Landriani had announced that the diamond, inflamed by brafs wire, burnt 
like it in oxygen gas, and with the utmof brightnefs : he, indeed, ex- 
cepted the Brafilian diamonds, which he was not able to inflame by thefe 
means. Annales de Coemie, Vol. XI. p- 156. 

. I thought 


on the Combu/ftion of the Diamond. 64 


I thought it might be of fome importance to preferve the 
fubject of thefe obfervations, and that it would not difgrace 
the collection of the cabinet of the School, with an infcrip= 
tion allufive to the experiment to which it had been fub- 
jected. “Another diamond: was therefore deftined to be put 
nto the apparatus, in order that it might be there fubje&ted 
to entire combuftion. This diamond was alfo a pretty regular 
oétaedron, of a much more beantiful water than the pre~ 
ceding, and weighing 209"1 milligrammes, 3°77 grains. 

As the feafon was already fo far advanced that it left us 
no hope of a folar focus as ftreng as that from which we had 
obtained fo little effect with the lenfes we had employed, I 
was defirous of terminating the experiment with the great 
Jens of Tfchirhaufen; and the clafs granted me permiffion 
to také it from their cabinet, 

This lens,° as is well known, is 86:6 centimetres (32 
inches) in diameter, and 211°076 (73 inches) focus. We 
augmented its power {till more by catching the luminous 
cone with the {mall lens of the cabinet of the Inftitute, the 
ditk of which is 37°89 centimetres, and the focus 56°83, 
which in this pofition was fhortened to 5°41 centimetres. 

A firft fitting gave fcarcely any figns of a commencement 
of combuftion. Next morning, the luminous difk having 
fallen on one of the parts of the bell which was thickeft, it 
occafioned it to crack. It was therefore no longer poflible 
to compare the volume of the gas before and after the ope- 
ration, nor to diftimguifh and afcertain the quantities of the 
products. We confined ourfelves to making lime-water pafs 
through the interior of the bell before the fiffure had fuffered 
a fenfible quantity of common air to enter, and we obferved 
that it was much troubled. 

The diamond which had been laft expofed was noways 
changed at its furface: it had, however, loft two decimilii- 
grammes of its weight; which was verified by the fame 
balance with which it had been weighed, and which is ca- 
pable of marking, in a very fenfible manner, thefe fractions 
of the milligramme. Thus we were obliged to adjourn the 
experiment till the next fummer, in order to find a more 
favourable fun, and to have time to provide a new apparatus, 

[To be continued, | 


XIII. Account 


E620") 


XIII. Account of the Proceffes ufed by Mr. SHzLDRAKE fe 
- feparate the Mucilage from Lanfied Oil, and to diffolve 
Copal in Spirit of Turpentine, and in Alcohol *, 


To feparate the Mucilage from Linfeed Oil, 


I HAD read in fome book, the title of which I do not 
recollect, that linfeed oil might be purified by fhaking it 
with water, which would imbibe the impurities, and leave 
the oil more limpid. I tried this experiment by fhaking 
linfeed oil with warm water; and was furprifed to find they 
did not feparate, but remained united in the form of emul- 
fion. I then boiled them together, and found their tendency 
to feparate diminifh. As it is the known property of gums 
or mucilage to keep oil and water united in this ftate, T was 
induced to fufpect the prefence of mucilage in linfeed oil. 

I had read-in Doffie a method of preparing what he calls 


fat ail, Tt is effected by placing linfeed oil in a fhallow pe 


expofed to the heat of the fun, and ftirring it frequently : 
a certain time it lofes its property of drying, thickens, sc 
acquires a degree of tenacity that makes it proper for a fize 


or cement for gilders, &c. A fimilar fubftance is alluded to 


by Leonardo da Vinci. 
Taking the exiftenece of mucilage in this oil for granted, 


T conjectured that the alteration, produced in its texture by 
Doffie’s procefs, arofe from the evaporation of fome of its 


principles, and the more intimate union of the reft in con- - 


fequence of that evaporation. To verify this conjecture, I 
tried the following experiment : 

I filled a half-pint phial full of linfeed oil, corked and tied 
it fecurely over with a bladder. This I expofed to the heat 
of the fun in fummer, during the whole day: after it had 
remained a few days in this fituation, the upper part of the 


* From the Tran/a‘tions of the Society for the Encouragemeni of Arts, &c. 
Vol. XVil. The prefent may be confidered as a continuation of Mr, 
Sheldrake’s paper on Painting in Oil, in a manner fimilar to that praétifed 
in the ancient Venetian School, publifhed in Yol. XVI: for a copy of 


which fee Phil. Mag. Vol. I. ‘ 
phial 


Procefs for feparating Mucilage from Linfeed Ol. 63 


“phial was covered with drops fimilar to thofe produced by 


holding a wet bottle to dry before the fire. I then fhook it 
well, w vhich made the contents look muddy, and fet it to reft 
again. After a time it became clear, and a portion of tranf- 
parent liquof, like water, lay at the bottom. I then repeated 
the fhaking and {etting it to reft, till no beditiineal quantity 
of this fluid was feparated: 

By trying this~experiment repeatedly upon oils. procured 
from different places, I found that fome oils afforded much 
more mucilage than others. From fome I feparated a third 
part of mucilage e; from others, a pint would not afford more 
than a table- fpoontuh and fometimes lefs. Whether this 
difference in the refult was radically in the oils, or from a 
difference in the proceffes conduted by means fo variable as 
the heat of the fun, I am not able to afcertain. 

Upon trying the fame experiment with nut and poppy oil, 
I found the es refult, but in a different degree. The 
average quantity afforded by nut oil was, I bling, not more 
than a third part of the ayerage of linfeed oil; and the ave- 
rage of the poppy oil was not fo much asa fixth, In fome 
eafes, particularly of the poppy oil, I did not obtain any. 

The colour of the oil always sented as the mucilage 
was abftracted; but the mucilage was always as colourlefs 

as water. It is a queftion I w ill not pretend to decide, whe- 
ther the colour of thefe oils depends upon the prefence of the 
mucilage, or upon any other principle which is deftroyed by 
the aétion of light. I have in fome inftances had the oil as 
éolourlefs as water. 

This decompofition of the oils, if it may be fo, called, is 
curious, as proving the mucilage in them; but, as it is very 
troublefome, may it not be advifable to prefer thofe which 
have naturally the-leaft mucilage in their compofition ? 

After pouring the oils from the mucilage, I put feveral 
quantities of the latter together, and found them mix with- 
out any difficulty. I mixed this mucilage with water, and 
found it unite with it in any proportion without becoming 
turbid. I laid it upon plates of metal, expofing them to dry 
an the fun and before the fire, and, when dry, wafhed them | 
with a {punge and water: but it fhewed no tendency to dif- 

6 folve ; 


ae 


64 Procefi to diffilve Copal i in Spirit of Turpentine. 


folve; though, while in a liquid ftate, it feemed to poflefs alf 


the properties of a gum. 

As the proceffes by which I diffolved the amber and copat 
to make the oil varnifhes, are to be found in many books, 
and as it will be better for artifts to purchafe tian attempt 
to make thofe varnifhes, it can fearcely be thought neceffary 
to aetail thole proceffes here: but, as I believe the methods 
‘by which I diffolved the copal in fpirit of turpentine. and 
fpirit‘ef wine are not known, I fhall now fubjotn them. 

To diffilve Copal in Spirit of Turpentine. 

N.B. Whatever quantity is to be diffolved, fhould be put 
into a glafs veffel capable of containing at leaft four times as 
much, and it fhould be high in proportion to its breadth. 

Reduce two ounces of copal to {mall pieces, and put them 
into a proper veffel. Mix a pint of fpirit of turpentine with 
1-8th of fpirit of fal-ammoniac ; fhake them well together ;- 
put them to the copal; cork the glafs, and tie it over with a 
ftring or wire, making a fmall hole through the cork. Set: 
the glafs in a fand-heat fo regulated as to make the contents 
boil-as quickly as poflible, but fo gently that the bubbles 
may be counted as they rife from the bottom. ‘The fame 
heat muft be kept up exactly till the folution is complete. 

- It requires the moft accurate attention to fucceed in this 
operation. After the fpirits are mixed, they fhould be put to 
the copal, and the neceffary degree of heat be given as foon 
as poffible. It fhould likewife be kept up with the utmoft 
regularity. If the heat abates, or'if the fpirits boil quicker 
than is dire&ted, the folution will immediately ftop, and it 
will afterwards be in vain to proceed with the fame mate- 
rials; but if properly managed, the fpirit of fal-ammonia¢ 
will be feen gradually to defeend from the mixture and attack 


the copal, which fwells and diffelves, except a very fall 


quantity which remains undiffolved. 

It is of much confequence that the veffel fhould not be 
opened till fome time after it has been perfectly cold. It has 
twice happened to me, on uncorking the vefiel when it was 
not warm enough to affect the hand, that the whole of the 
contents were blown with violence againft the cieling. It is 

hikew ife 


fe 


Ee 


Procefs to diffelue Copal in Alcobol. 6s 
Vikewifé important that the fpirit of turpentine fhould be of 
the beft quality. T have never fucceeded with that w hich is 
fold at the colour-fhops; but whenever I procured my fpirits 
at Apothecaries’ Hall, I have diffolved the copal, by the pro= 
cefs I have decribed, without difficulty. 

This varhifh is of a rich deep colour when viewed in thé 
ag but feems to five fo Coléue to the pictures i it is laid 
on: if left iri the damp, it remains facky, as it is called, a 
tad time; but ifkept in a warm room, or placed in the 
fun, it diies as well as any other turpentine varnith; and 
when dry, it appears to be as durable as any other folution 
of copal. 

To diffelve Copal in Alcohol: 

Diffolve half an ounce of catnphire in a pint of alcohol 
aye it in a circulating glafs, and add four ounces of copal ir 
mall pieces; fet it in a fand-heat, fo regulated that the bub- 
bles may be counted as they rife oe the bottom; and con- 
tinue the fame heat till the folution is completed. 

Camphire aéts miore powerfully upon copal that any fub- 
ftance that I have tried. If copal is finely powdered, and 4 
{mall quantity of dry camphire rubbed with it in the mortar, 
the whole becomes in a few minutes a tough coherent mafs. 
The procefs above defcribed will diffolve more copal thah the 
menftruum will retain when cold. The moft economical 
method will therefore be to fet the veffel which cofitains the 
folution by for a few days; and when it is perfectly fettled 
pour off thé clear vatnifh, and leave the refiduum for a fu- 
‘ture operation. 

This is the brighteft folution of Gopal that I have feen: it 
ig an excéllent varnitth for pictures 3, and may perhaps be found 
to be an improvement in fine Japan works; as the {toves 
ufed in drying thofe articles may drive off the camphire en- 
firely, arid leave the copal pure and colourlefs on the work: 

N.B. Copal will diffolve in fpirit of turpentine, by the 
addition of camphire; with the fame facility, but not in the 
fame quantity, as in alcohol. 

At the time I determined to lay the preceding papers 
before the Society, I conceived that the quick and cer ain 

SV OL, Y. K manner 


66 Procefs to diffalue Copal in Alcohol. 


manner in which the vehicle dried, was one of its adyan- 
tages. But as that circumftance has been objeéted to, and 
in fome cafes really is a difadvantage, I have fince endea- 
voured to remove that obje€tion by the following procefs : 

Put a pint of nut or poppy oil into a large earthen veffel ;. 
make it boil gently upon a flow fire; put in by degrees two. 
ounces of cerufe, and ftir it Setiargite till the whole is dif 
folved. 

Have ready a pint of the copal oil varnifh heated in a fe- 
parate veffel ; pour this by degrees into the hot oil, and ftir 
them together till all the {pirit of turpentine is diflipated ; let. 
it then be fet by till cold, when it will be fit for ufe. 

It is obvious, that, as this is a compound of the copal var- 
nifh with the leaft exeeptionable of the drying oils, it will 
partake of the properties of each of its component parts. It 
gives lefs brightnefs and durability to colours than the varnifh | 
will, but more than oil: but as it certainly may be ufed int 
painting in the fame manner as any other drying oil, and 
gives more brightnefs and durability to colours than they 
can derive from any other oil, it is not unreafonable to ap 
pofe that it will prove ani advantagcous vehicle. 

I have mentioned fpecific quantities of the ingredients 
but it is eafy to fee that the relative proportions may be ya- 
ried according as it is required to dry fafter or flower. It 
mutt be remarked too, that whenever the mixture is to be 
made, both the ingredients fhould be hot; becaufe, if either 
of them 1s cold, the mixture becomes turbid, and a part, 
often the whole of the copal, is precipitated + but this incon- 
venience is avoided by mixing and boiling them together, as 
I have dire&ed. It mut likewife be obferved, that after 
fome time a fpontaneous alteration takes place, which di~ 
minifhes, and at laft deftroys the drying quality of this mix- 
ture: it will therefore be advifable to nf it freth, or at leatt 
not to ufe it after i it has been made more than a month or 
fix weeks, 


XIV, Proce(s 


[ 67 ] 


XIV. Proce/s for producing the Lights in Stained Drawings. 
By Mr, Francis Nicuotson, of Rippon, York/bire*. 


Tu difficulty of preferving the lights in ftained draw- 


ings, with freedom and precifion, is fo univerfally felt by thofe 
who cultivate that branch of the arts, the practice of which 
is every day growing more extenfive, that the ftatement of 
this circumftance alone is fufficiént for the introduction of 
the following procefs, by which that difficulty is removed, 
and by which all the effec of body-colour may be obtained 
without any of its inconveniences or defects. It is appli- 
cable to every fubject, to the richnefs of foliage, of rocks, or 


of foreground ; and in ruins, their moft picturefque appen- 


dages of hanging fhrubs, weeds, &c. may be expreffed by it 
with the utmoft fharpnefs, and with all the lightnefs and 
freedom of which body-colour or oil-painting are capable. 

The principle of this procefs confifts in covering the places 
where the touches of light are intended to be, with a com- 
pofition not liable t6 be difplaced By wathing over it with 
the colour, and fuch as may be afterwards removed by a fluid 
in which the colours ufed in water are not foluble. 

This compofition, or {topping mixture, is made by diffoly- 
ing bees-wax in oil of turpentine, in the projrtion of one 
ounce of wax to five ounces of the oil; and, as near the time 
of ufing it as may be convenient, grind with the pallet-knife 
as much flake white, or white lead, in oil of turpentine, as 
Inay be wanted at one time; dilute it with the above foly- 


* The Society for the Encouragement of Arts, &c. haying lat feffion 
received from Mr. Nicholfon, of Rippon in Yorkfhire, a Drawing in+ 
tended as a fpecimen of the procefs for producing the lights ia ftained 
drawings, by removing, after the thadows are wafhed in, the colour where 
the lights are required, giving by this means the effet of body-colour 
with greater clearnefs, and without any of its difadvantages; and it Ap» 
pearing that Mr. Nicholfon’s method of tinting drawings promifes to be 
of ufe in the prattice of drawing in water-colours, and produces « more 
Spirited effeét, the Soc ety agreed to My. Nicholion’s propofal, and pur- 
chafed from him, at the price of twenty guincas, the complete procefs for 
performing the work, as communicated in the above paper, 

Ka tien 


th 


68  Procefs for troducing Lights in Stained Drawings, 


tion until it will work freely with the pencil, and appear on 
the paper, when held between the eye: and the light, to be 
opaque. It is neceffary to obferve this, or the firft touches 
will not be fufficiently vifible, after being wafhed over with 
the colours, to afcertajn the places of the fecond. It is alfo 
neceffary to ufe a frame inftead of the drawing-board, or to 
pafte the paper on the frame of the drawing-board.fo as to 
remove the pannel; becaufe the firft and fecond touches 


muft be put on with the drawing placed between the eye’ 


and the light, as they will be sn vifible in that fituation, 
On this frame pafte the paper wet, fo as to dry firm: when 
quite dry, draw the outline, and proceed as follows :— 

1ft, With a fine fmall hair pencil, and the flopping mix- 
ture, cover thofe places where the clear whitenefs of the 
paper may be wanted, except in the fky: let it dry a few 
minutes; then wet the paper on both fides, and while it is 
wet wath the fky. The fhadows of the clouds, diftances, 
and general breadths of fhadow, muft be put in with the 
grey tint; and over the places of the light, wath the tints of 
iG brighteft light 5 thofe will be generally ‘yellow ochre of 
light red, 


“Phe light of the clouds may be co ved {harp by preffing 


on that part a piece of tiffue-paper previgus to the waging 
of the fky; this, by abforbing the fuperfluous moifture, will 
Prevent the eolour from fpreading farther than is defired, 
Suffer the whole to be very dry; and, 

adly, Touch jn with the ftopping mixture, the fharp and 
prominent parts of the brighteft lights; let them dry a few 
minutes, then wath over hati with the tjnts of the next 
degree of ijght, 

3dly, Stop with the mixture the fecond order of touches, 
and wafh aver them with the middle tints; ftrengthen alfo 
at the fame time the breadths of {hadow. — 

gthly, Stop, with broad touches of the mixture, the places 
of the middle tint ; uniting them to the former touches, and 
extending them fo as to graduate the middle colours into the 
fhadow : ftrengthen the fhadows, making them nearly as 
dark as they are intended to be, and let the whole be per= 
fectly dry. 

Then 


Travels through Egypt and Syria, By. 


‘Then take oil of turpentine, and with a fponge, or hog’se 
hair pencil, wath over the places where the mixture has been 
ufed, rubbing it with the brufh until it be diffolyed: clear it 
away with a linen rag, and wafh it with more oil of turpentine 
fo long as any white lead appears; then let it dry. 

. Warm the drawing; then with a foft bruth and highly- 
rectified {pirit of wine wafh the places where the oil of tur- 
pentine has been ufed, to clear away the remainder of it: 
rub the drawing lightly on the face, but fponge it well on. 
the back, 

When dry, tint down the lights where it may be wanted ; 
harmoniie the colouring, and cut the fhadows to effect, with 
ftill darker tints as may he neceffary. 

If other touches of light fhould afterwards be wanted in 
the fhadowed parts, the colour may be eafily removed by a 
pencil formed of {ponge, with water fufficient to produce 
them with as much ftrength as can be defired; then ftop 
them with the mixture; wath the fhadow over the touches, 
bringing it to the ealour taken off; and, when dry, remove 
the mixture with the oil of turpentine ayd {pirit of wine. 


_XY, An ic of Mr. Brown’s Travels through 
Egypt. and Syria, &c, 


[Continued from page 414 of the lat Volume.] 


Doatwe three or four days enfuing, Mr. Brown fuffered 
fo violent a relapfe as to be unable to perform the common 
offices of life, and even to fuppofe that it was nearly atan 
end, The moment any fymptoms of amendment appeared, 
he fent word to. the Melek that he wifhed to be introduced 
to the Sultan, and then, as foon 4s poflible, to he difmiffed. 
No reply was made to this meflage; but the following day 
he came to the tent, with fome of his attendants, and defired 
to fee the merchandife he had brought with him. As to 
part of the articles, confifting of wearing apparel, &c. fuited 
to the great, our traveller r¢adily confented: but this was not 
fufficient ; the Melek infifted on feeing the contents of a {mall 
et which chiefly contained articles afeful to himfelf, but 

not 


od An Account of Mr. Brawn’s Travels 


not defigned for fale. There were alfo in it fome Engliffy 


piftols, which he intended to avail himfelf of as prefents at 
Sennaat, or wherever elfe he might be able to penetrate. 
Mr. Brown, therefore, pofitively refufed to open the cheft: 
the Melek threatened to have it broke open; and, as his at~ 
tendants were proceeding to do fo, Ali Hamad, the nran who 
attended Mr. Brown, took the key from its concealment and 
opened the box. Every thing was pulled out and examined, 
and many {mall articles appeared io more: the piftols were 
referved to be taken by the Sultan, after a violent but fruit- 
Jefs altercation at the valuation made by his own fervants ; 
atid Mr. Brown’s tetefcopes, books of which they knew not 
the ufe, with his wearing apparel, &c. were gracioufly left 
him. The valuation was made the following day: the whole 
was eftimated at thirty-eight head of flaves, being at the 
market price worth eighty, exclufively of a prefent of value 
for the Sultan. A pair of double-barrelled piftols, filver 
mounted, which coft in London twenty guimeas, were valued 
at one flave; which can in general be purchafed, by thofe 
who are experienced in that traffic, for the value of fifteen 
piafires in Egyptian commodities. On this Mr. Brown ex- 
claimed, that. if they meant to plunder, and if bargain and 
fale were not conducted in the country by the confent of the 
parties, but by force, it would be better to take the whole 
gratis. No anfwer was made; but the day following two 
camels were brought him as a prefent. 

The violent manner in which our traveller’s property had 
been fetzed, and the general ill-treatment he received, bad 
much aurmented his diforder. He had been fifteen days in the 
tent expofed to great variations of temperature; and it being 
at the clofe of the rainy feafon, he could rarely obtain water to 
drink, though tormented with thirit. He jndged, therefore, 
that the only means of reftoration were, to return to Cobbé, 
and avail himfelf of the fhelter of a clay houfe and privacy, 
the want of which he had fo fenfibly felt. The Melek, bemg 
in pofleffion of the greater part of his property, having left 
him only as much as would fupply the wants of a few 
months, did not feem very anxious about his fiay. Mr. 
Brown hired therefore two Arabs, and with the camels given 

to 


\ 


through Egypt and Syrias _ » gi 
to hima, and the property that remained, arrived on the third 
day at the place from which he had come. In the intervals 
of his illnefs he vifited the chief perfons of the place; and as 
the eyes of the people became habituated to him, he found 
his fituation growing fomew hat more tolerable. Though 
idle during the eoutfe, of the winter refpecting the ‘nied ae 
objects ve his voyage, he grew, of courfe, more familiar with 
ihe manners and particular dialet of the country; for the 
Arabic fpoken in it differs materially from the vernacula? 
idiom of Egypt. 

The following fummer (1794) Mr. Brown, having in 
fome degree recov ered his ftrength, determined to go and 
refide for a time near the Sultan, both to fupplicate for re~ 
drefs of what he had already fuffered, and to embrace any 
opportunity that might offer of preffing his requeft for per- 
miffion to advance. On his arrival at El Fafher, his good 
friend Melek Mifellim beifg employed by his matter in the 
fouth, he went under the protection of the Melek Ibrahim, 
one of the oldeft perfons in authority there, and took up his 
jodging in the houfe of a man named Mufa. During Mr. 
Brown’s ftay-at El Father, of three entire months, he was 
folicitous to attend regularly the levees of the Sultan, which 
were from fix in the morning till ten; but could very rarely 
obtain admittance, and when he did he had sio opportunity 
of fpeaking. After waiting in fruitlefs expetation at Ef 
Fafher, when the time of his departure was drawing near, an 
accident happened, which, though not of the moft pleafing 
kind, contributed to make him noticed, and obtained for 
him at length an interview with the Sultan. One day, as 
he was reading in his hut, a female flave belonging to the 
houfe, a girl chant fifteen, came to the door of it, when, 
from a whim of the moment, he feized the cloth that was 
round her waift, which dropped, and left her naked. Chance 
fo determined that the owner of the flave paffed at that 
time, and faw her. The man immediately threw his turban 
on the earth, and exclaimed—Ye believers in the Prophet 
hear me! Ye faithful avenge me! (with other fimilar ex- 
preflions :) a Caffre has violated the property of a defcendant 

tak 4 of 


vE3 An Account of Mr. Brown's Travels 


of Mohammed! When a number of people was collected 
around him, he related the fuppofed injury he had received irt 
the ftrongeft terms, and exhorted them to take their arms 
and facrifice the Caffre. He had charged a carbine, and 
affected to come forwards to execute his threats, when fome 
one of the company, who had advanced fartheft and faw 
Mr. Brown, called out to the reft that he was armed, and 
prepared to refift. It was then agreed among the affembly 
that fome method of punifhment might be found which pro- 
miufed more fecurity and profit to the complainant, and woulkt 
be more formidable to the guilty. The man who aéted as 
his broker was to take tlie flave as if fhe had really been vio- 
Jated, and agreed to pay whatever her mafter fhould charge 
as the price: The latter had the modefty to afk ten head 
of flaves; and if Mr. Brown carried the matter before the 
Cadi, which he fuppofed he would hardly venture to do, he 
had fuborned witnefles to prove that he had received of hiny 
property to that amount. 

On Mr. Brown’s removal from Cobbé to El Fafher, he 
had caufed his fmall remaining property, among which were 
a few articles of value, but many of much ufe to’ him, to be 
fodged in the houfe of Hoffein, the owner of the flave, and 
his companion. On his return thither, which happened a 
few days after the accident, he claimed it; but they refifted, 
as they alleged, at the fuit of his broker, and would not de- 
fiver it till the value of ten flaves fhould be paid to him. Mr. 
Brown from the firft confidered their conduct as fo violent 
that if it reached the ears of government the claim would 
unqueftionably be abandoned; and, indeed, his adverfaries 
had refted their expectations only on the timidity which 


they had been accuftomed to obferve in Chriftians of the © 


country, whofe accufation and condemnation are in faét the 
fame. He had not negleéted to give the tranfaction all the 
notoriety he could without having recourfe to public autho- 
rity, and thofe to whom he had applied were decidedly in his 
favour. He therefore now went to his adverfaries, Hoflein 
and his companion, and in their prefence offered to Ali 
Hamad a promiffory note for the yalue of ten flaves at the 
market= 


through Egypt and Syria. 93 
market-price on his arrival at Kahira, It was however re- 
fufed; and his cheft, containing fome German dollars and 
other articles, was ftill detained. The reft was given up. 

Mr. Brown had been told that the Sultan was apprifed of 
the tranfaction previoufly to his departure from El Father, 
and that he intended to grant him redrefs; but after waiting 
about fifteen days without hearing any thing farther of his 
intentions, being weary of fuffering, he determined to return. 
He had been arrived but a fhort time when a fulganaway; 
or meflenger, came exprefs from Court, with orders for him 
to repair to El Father immediately. The objeét of the mef- 
fage was kept a profound fecret, nor could he difcover whe- 
Sher it portended g good or evil, He left Cobbé the fame even- 
ing, and arrived at the end of his journey the day following 
about noon. He repaired as before to the Melek Ttcahin, 
who on the following day introduced him at the public 
audience. The Sultan, as he retired to the palace after it 
was over, ordered all the parties to appear. Being come 
within the inner court, he ftopped the white mule on which 
he was mounted, and began a fhort harangue, addrefling 
himfelf to Hoffein and Ali Hamad Mr. Brown’s fervant, 
in which he cenfured, in a rapid and energetic ftyle, their 
condu& towards him :—** One,” faid he, turning to Ali; 
*6 calls himfelf Wakil of the Frank; if he were a Sherif and 
a Muflim, as he pretends, he w ould know that the law of 
the Prophet permits not a Mutlim to be Wakil to a Cafre: 
another calls himfelf his friend: both are agreed in robbing 
him of his property, and ufurping the authority of the laws. 
Henceforth I am his Wakil, and will proteét him.” He 
then ordered the parties to repair to the houfe of Mufa Wul- 
lad Jelftin, Melek of the Jelabs, under whofe appropriate 


jurifdiction are all foreign merchants. Mr. Brown here. 


gives the following account of the manner in which he had 
been before received by the Sultan: 

“On my firft audience,” fays Mr. Brown, ‘ I was too 
ill to make much obfervation. He was feated at a diftanoe 
from me; the vifit was {hort; and I had no opportunity of 
opening a converfation. He was placed on. his feat (céz/) 
at the door of his tent, Some perfon had mentioned to him 

Vou. V, L my 


94 An Account of Mr. Brown's ice 


my watch and a copy of Erpenius’s grammar I had with me, 
Ue afked to fee both; but after cafting his eyes on each, he 
returned them. The prefent I had brought was thewn him 3 
for which he thanked me, and rofe to retire. 

*“* During the following fummer the firft time F got ad-. 
miffion to him he was holding a diyan in the outer court. 
He was then mounted on a white mule with a fearlet deni/h, 
and had on his head a white turban; which however, toge- 
ther with part of his face, was covered with a thick muflin. 
On his feet were yellow boots; and the faddle on which he 
was feated was of crimfon velvet, without any ornament of 
gold or filver. His fword, which was broad and ftraight, 
and adorned with a hilt of mafly gold, was held horizontally 
in his right hand. A fmall canopy of muflin was fupported 
over his head. Amid the noife and hurry of above a thou- 
fand perfons, who were there aflembled, I was unable to 
make myfelf heard, which the nature of my fituation enabled 
me to attempt, though not exactly conformable to the eti- 
quette of the court, that, almoft to the exclufion of ftrangers, 
had appropriated the divan to the troops, the Arabs, and 
others connected with the government. 

“© On another occafion I contrived to gain ‘admittance te 
the interior court by a bribe. The Sultan was hearing a 
caufe of a private nature, the proceedings on which were 
only in the Furian language. He was feated on a kind of 
chair, which was covered with a Turkey carpet, and wore a 
red filk turban; his face was then uncovered; the imperial 
fword was placed acrofs his knees; and his hands were en- 
gaged with a chaplet of red coral. Being near him, I fixed 
my eyes on him in order to have a perteét idea of his coun- 
tenance; which, being fhort-fighted, I had hitherto fearcely 
found an opportunity of acquiring. He feemed evidently dif- 
compofed at my having obferved him thus, and the moment 
the caufe was at an end he retired very abruptly. Some 
perfons to whom I afterwards remarked the circumftance, 
feemed to think that his attendants had taught him to fear 
the magic of thie Franks, to the operation of which the habit 
of taking likeneffes is imagined by fome of the Orientals to 
eonduce. He is a man rather under the middle fize, of a 

complexion 


through Egypt and Syria. 95 


complexion aduft or dry, with eyes full of fire, and features 
abounding in expreffion: his beard is fhort, but full; and his 
countenance, though perfeétly black, materially differing 
from the negro: though fifty-five years of age, he poffeffes 
much alertnefs and activity. 

** At another of my vifits I found him in the interior 
court, flanding with a long ftaff tipped with filver in his 
right hand, on which he leaned, and the {word in his left, 
He then had chofen to adorn his head with the folds of a 
red filk turban, compofed of the fame material as the wefern 
Arabs ufe for cin@ture. The Melek Ibrahim prefented him, 
in my name, with a {mall piece of filk and cotton of the ma- 
nufaGure of Damefcus. He returned in anfwer, Barak ulla fi! 
May the bleffing of God be on him! a phrafe in general ufe 
on receiving any favour; and inftantly retired, without giv- 
ing me time to urge the requeft, of which I intended the 
offering fhould be the precurfor. It is expected of all perfons, 
that, on coming to El Father, they fhould bring with them a 
prefent of greater or Jefs value according to the nature of the 
bufinels in hand. It is no lefs ufual, before leaving the royal 
refidence, to afk permiffion of the Sultan for that purpofe. 
With this latter form, which was to me unpleafant, I fome- 
times complied, but more frequently omitted it. But-on this 
eccafion, having been long refident there, I thought fit to 
make a laf effort to promote my defign. The day preceding 
that which I had fixed for my return, happened to be a great 
public audience. I found the monarch feated on his throne 
{cérfi) under a lofty canopy, compofed not of one material, 
but of various ftufls of Syrian and even Indian fabric, hung 
Joofely on a light frame of wood, ne two pieces of the fame 
pattern. The place he. fat in was fpread with {mall Turkey 
carpets; the Meleks were feated at fome diftance on the right 
and left; and behind them a line of guards, with caps orna- 
mented in front with a fmall piece of copper and a black 
oftrich feather. Each bore a {pear in his hand, and a target 
of the hide of the hippopotamus on the oppofite arm: their 
refs confifted only of a cotton fhirt of the manufacture of 
the country. Behind the throne were fourteen or fifteen 
eunuchs, clothed indeed fplendidly in habiliments of cloth 

La or 


76 Travels through Egypt and Syria. 

or filk, but clumfily adjufted, without any regard to fize or 
colour. The’ fpace in front was filled with fuitors and {pec- 
tators to the number of more than fifteen hundred. A kind 
of hired encomiaft {tood on the monarch’s left hand, crying 
out a plein gorge during the whole ceremony :—** See the 
buffalo, the offspring of the buffalo; a bull of bulls; the ele- 
phant of fuperior ftrength; the powerful Sultan Abd-el- 
rachman-el-rafhid ! May God prolong thy life, O matter ! 
May God affift thee, and render thee victorious!’ From 
this audience, and thofe which preceded it, I was pa to 
retire as I had come, without effecting any thing.”’ 

Mr. Brown’s reception with Mufa Wullad. Jelfiin was 
very different from that which he had experienced in the 
houfe of Mifellim or Ibrahim. His behaviour towards him 
was complacent, and he affected to feek opportunities of 
hearing his fentiments on fuch fubjects as occurred, In 
obedience to the Sultan’s command, Mr. Brown now gave 
in an exact flatement of the property he had loft, and fub- 
ftantiated the proof by the ftrongeft circumftantial evidence, 
With regard to the flave, the moft complete redrefs was af-’ 
forded him: the charge brought again{t him was judged 
abfolutely futile, and fhe was reflored to her mafter; while 
he, on the other hand, was compelled to give up the chett, 
&e. which had been violently with-held.. The plunder 
which had fallen into the hands of his fervant, and his ac- 
complice, was not fo eafily reftored. ‘The Melek, tired of.a 
gratuitous juftice, began to think that a lucrative compofi- 
tion was more eligible. The offenders, who had been obfti- 
nate in the firft inftance, feeing how the caufe relative to 
the jarea (female flave) had been decided, thought proper to 
offer to the Melek marks of their gratitude for the lenity they 
expected from him; and the Sultan was unwilling to ima- 
eine that the fuflerings of a Caflre could fall heavy on him- 
felf at the day of final retribution. At length the Melek, 
who in reality was fupreme arbiter of the contefl, contented 
himfelf with giving Mr. Brown the intrinfic value, about four 
head of flaves, iiffteda of twenty-four or twenty-five, which 
at firt he had unequivocally declared ‘due to him, and pro- 
souttd he fhould receive. Thus the matter was terminated, 

[ To be concladediin the nex: Number. ] 


XVI. Den 


XVI. Defcription of the Paliorum Lacus, or Lake Paleus, in 
the Valley of Noto in Sicily. By M. DoLtomigu*, 


Tus {mall but very remarkable lake, fituated at the 
diftancegof two miles weft from the town of Palagonia, or of 
a mile from Mineo, is furrounded by volcanic mountains, 
and lies in a fmall plain fomewhat hollow towards the mid- 
dle. This plain is half furrounded by fteep rocks, which 
_ give it the appearance of a monftrous crater, that has funk 
down by fome convulfion. The lake is placed in its centre, 
and, as it were, in the middle of a funnel. Its depth often 
varies, and confequently its circumference. . In the winter 
time it may be about fixty or feventy fathoms in diameter, 
and about ten in depth; but in fummer, when great drought 
prevails, it is often entirely dry. At the period when I faw 
it, which was in the month of May, it rated an oval about 
thirty” fathoms in length and twenty in breadth: its depth 
was about five or fix. It had a ftrong fmell of Jew’s pitch, 
or afphaltes, even at a confiderable diftance. The water in 
its colour inclined a little to green, and had an exceedingly 
naufeous and difagreeable tafte. I was told that the water was 
often tepid; but it had, at the time when I examined it, the 
temperature of the atmofphere. In feveral parts of it I ob- 
fervyed a violent bubbling, and particularly in four places near 
the middle. This bubbling was ftronger at certain intervals, 
and the water was thrown up fometimes to the height of 
two or three feet, rifing in this manner every five or fix 
minutes. There are periods when this boiling is ftronger 
or weaker; but on thefe occafions no other noife is heard 
than that produced by the motion of the water. 

When the lake is dry, one may without danger examine 
its centre, where there are feveral deep holes. From thefe 
holes currents of air, fomewhat warm, continually arife, and 
throw back fand and other bodies if put into them. It is 
this aériform vapour which, when the bafon is full, forces 
pp the water as before defcribed, and makes it to be covered 


* From Magazin fur das nencfle aus der Phyfik, Vol.UII. 
with 


78 Defcription of the Lake-Palius. ° 
with foam. It would, no doubt, be important to examine 
accurately the nature of this vapour; but though I was pro- 
vided with the proper apparatus, I could not obtain my ob- 
ject, becaufe I durft not venture to wade into the water in 
order to reach the places where the bubbling appeared, and 

which were at a confiderable diftance from the ban 
The mud at the bottom and on the bank, which has a 
black colour, is tenacious, and fmells like pitch. A little 
petroleum has alfo been fometimes found at the furface of 
the water. The whole foil of the fmall plain confifts of 
black, tough, refinous, inflammable earth. A few years ago 
fome ftraw huts in this neighbourhood having been fet on 
fire, the fire was communicated to the ground, which burnt 
with a whitifh dull flame, like that of the inflammable fprings 
in Dauphiny, during feveral months, and was extinguifhed 
with the greateft difficulty, as the fire, when deftroyed in 
one place, broke out in another. Since that period great 
care is taken not to kindle fire in the neighbourhood. @F rom 
this phenomenon I am induced to think, that the air which 
rifes through the water of the lake, and which probably finds 
a paflage through the ground, may be of an inflammable 
nature alfo; as the air of marfhes, which burns without any 
noife. The fertility of this {mall plain is fo great, that it pro- 
duces a moft abundant crop every year, without requiring 
much agricultural care. In walking over the ground a hollow 
noife is heard; which feems a proof of there being beneath 
the furface fubterranean cavities, like thofe of Solfatara near 
Puzzuolo. From thefe circumfiances there is reafon to think 
that this place has been formed from the remains of a fallen 
erater, a part of which is ftill {een in the furrounding moun- 
tains; and between this lake and that of Agnano near Na- 
ples, ioe is no other difference than the greater quantity of 
water in the one, and the more violent Ae of vapour in 
ihe other. Some affert that the vapour of this lake is mor- 
tal; and that no bird, or other animal, can be expofed to it 
without being killed. The vapour alfo which arifes from 
ihe ground is confidered as of a fuilocating nature, fo that 
people who lie down on the earth, or only bend their bodies 
towards it, are expofed to the greatelt danger; though one 
6 may 


.  Defcription of the Lake Palius: 79 
may walk over it without the leaft fear of any pernicions’con- 
fequences. All thefe phenomena have a great fimilarity ‘to 
thofe of the Grotto del Cane, near the lake Agnano. 

On the banks of the lake Palius there are found a great 
many {mall clufters of afhes and flag, exactly like thofe ad- 
hering to the fides of the craters of AZtna and Vefuvius. The 
mountains and lava around this lake exhibit the moft evident 
marks of their great antiquity, as in many places they are 
covered with calcareous ftones, from which it may with cer- 
tainty be inferred that they muft have originated at a time 
when the prefent continent was not inhabited. In the time 
of Diodorus Siculus, however, the crater, which forms the 
prefent bafon of the lake, fhewed traces of its internal in- 
flammation: as we are informed by this. hiftorian, that 
flames burft forth from this fpot; that the water poffeffed a 
confiderable degree of warmth; and that a horrid thundering 
noife was heard. Being extremely defirous to know whether 
a connection actually exifted between this volcano and that 
of tna, as they are at no great diftance from each other, 
I enquired whether any affinity had ever been obferved be- 
tween the eruptions of AZtna and the before-defcribed phe- 
nomena of the lake; and whether, during thefe eruptions, a 
fironger ebullition had taken place: but I was affured that 
no perfon had ever obferved any thing of the kind. 

The phenomena of this lake have at all times been at- 

tended with fo many fingularities as to give rife to fables 
without number: at prefent it is faid to be inhabited by a 
fairy. In ancient times thefe phenomena were afcribed to 
the fuperratural power and influence of fome deity. On this 

account 4 very celebrated temple, the remains of which I 
could not ind, notwithftanding all the trouble I took to dif- 
cover them, was erected here to Jupiter and the nymph 
Thalia. People fwore alfo by this lake, with the fame refpec& 
and folemnity as by the river Styx. What aftonifhed the 
ancients, and what even at prefent excites the wonder of all.,, 
thofe who vifit this lake, is the inceflant ebullition of the 
water, though the leaft increafe is not obferved in it on the 
bank. 

> ete neighbouring mountains I found under the lava a 
: refinous 


4 


$0 Objervations on the Fog of 1783. 


refinous ftrong-fmelling fubftance in horizontal ftrata, whick 
could be eafily divided into laminz of from one to two inches 
in thicknefs; but, in other refpects, the lava of this volcano 
exhibits nothing but what has been feen in the other extin- 
guifhed volcanoes in the neighbourhood. The Val di Noto 
is the only part of Sicily where traces of ancient volcanoes 
are found. Travellers, who imagined that they found fome 
of the like kind in other provinces, were either miftaken, or 
fuffered themfelves to be deceived by faife marks, 


XVIE. Obfervations on the Nature of the Fog of 1783. By 
M. Dr Lamanon, Corre/pondent of the Academy of Sci- 


ences at Paris*, 


V y HEN this fog, which may be called an eleétric fog, 
began to appear, I was at Sallon de Crau, in Provence, In 
order to free my neighbours and countrymen from uneafi- 
nefs as much as poffible, I wrote a letter to M. Artaud, 
editor of the Courier d’ Avignon, in which, after {peaking of 
the nature of the fog, I faid it would be deftroyed by the 
florms that would not fail to enfue. The event fully juftified 
this kind of prediétion. Having learned from the public 
papers that this phenomenon was not local, but almoft ge- 
neral throughout Europe, I made new obfervations, and tra- 
verfed the higheft Alps of Provence, Dauphiny, and Pied- 
mont; and, during the courfe of my travels, colleed inform- 
ation refpecting the fog, and the effects of the thunder. “But 
before I offer that explanation of the phenomenon, which 
appears to me mott probable, let me endeavour to give an 
accurate defcription of it. 


I. Nature and Effeéis of the Eleéiric Fog. . 


1. In almoft all countries the fog was preceded by a ftorm. 
2. It began the fame day at places very remote from each” 
other; as Paris, Sallon, Turin, Padua, &c. where it ap- 
peared, for the firft time, on the 18th of June. M. Senebier 


* From the Journal de Phyfique. 
wrote 


Odjervations on the Fog of t783. $i 
Wrote to the Count de Saluces, perpetual prefident of the 
Academy of Turin, that the fog was obferved at Geneva on 
the 17th. [read in the Afficbes of Pisa that it be- 
gan at Grenoble on the 2rft. 

3. A north wind prevailed in feveral places when the fog 
began ; and in other places, where it began the fame day, a 
fouth wind prevailed. The fog, after having ceafed, re-ap- 
peared in fome places by the Gan wind ; in others, by an 
eaft, weft, or fouth wind. 

4. The atmofphere was stot every where equally dry. At 
Sallon I obferved that it did not make falts enter into deliquef= 
cence; did not raife the hygrometer; did not prevent eva 
poration from being abundant; and did not even tarnifh 
glafs, which I expofed to it, The falt-pits at Hyeres, in 
Provence, ciryftallifed a fortnight fooner than ufual by the 
effect of the fog. Meffrs. Toaldo and Senebier obferved, the 
one at Padua and the other at Geneva, that the hygrometer 
did not reach the point which denotes humidity. In the 
Champfaur of Dauphiny, and at Turin, the fox was fome- 
times humid. 

5. The fun, which was never feen but through the fog, 
appeared very pale in the day-time; of a blood- rae colour at 
rifing, and {till more fo at fetting. 

6. At Sallon the fog fatictiinids diffufed a very diluirretabld 
fmell, difficult to be determined, and which fome believed 
to be fulphureous. This bad fmell was perceived in other 
places. . 

4. It was hurtful to the eyes. At Sallon, perforis whofe 
lungs were weak, found difagreeable effects from it. The 
inhabitants of the Champfaur informed me that feveral peo-= 
ple in that neighbourhood had violent pains in the head; 
and that, in general, they partly loft their appetite: The ins 
habitants of this valley are the greateft eaters in France s 
firangers, who refide among them, and drink their waters, 
_ eat almoft as much as they, and are not fo nice as ufual in 
tegard to the quality of their food. This I experienced in 
1783. 

' §8. In Lower Provence, Langnedoc, and other places, the 
- fog ripened the corn, and was favourable to the harveft. The 
Vou. V. M peafants 


a2 Obfervations an the Fog of 1783. 


peafants beheld, with the greateft fatisfaétion, the effest of 
the fog on their crops; and yet were afraid of it. In Upper 
Dahpinne and at Turin, it blighted feveral fields of wheat; 
and rendered copper buttons green. In other places it dried 
the plants. 

g. At Padua, Turin, Paris, Sallon, Grenoble, the baro+ 
meter remained almoft always ftationary at the point which 
denotes its mean ftate. 

10. There were fome days remarkably warm; but, in ge- 
neral, the months of June and Jaly were almoft every wheré 
lefs warm than ufual. That year there was no fummer on 
the high mountains of Provence and Dauphiny, where the 
thepherds of the plains of Crau and Camargue tend annually 
numerous flocks. 

11. There were every where ftorms of rain; and after 
thefe ftorms the fog fometimes increafed, but moft frequently 
was epeporney: 

. During the whole time of the fog, an eleCtric machine 
I had at Sallon emitted few or no fparks. A philofophie 
friend at Sorgues, near Avignon, wrote tome, that his elec- 
trometer always indicated a great deal of eleétricity in the 
atmofphere. 

13. On the 4th of July, at five in the morning, M. Nicos 
las, phyfician at Grenoble, and M. Plana, apothecary, took 
four meafures of fog and mixed them with two meafures of 
nitrous air: the abforption was 1-4th, and nothing remained 
but a gas, in which a candle became extinguifhed feveral 
times. Atmofpheric air generally contains nearly 1-3d of 
pure air (oxygen gas), and 2-3ds of mephitic air (azoti¢ 
gas). Fontana’s eudiometer gave the fame refult on the 7th 
of July: of three hundred parts of atmofpheric air, thirty-twe 
were abforbed. The air of the fog, mixed with inflammable 
(hydrogen) gas, did not prevent it from exploding when a 
lighted taper was prefented to the neck of the bottle in which 
it was contained. 

14. Almoft all thofe who have fpoken of this fog, fay that — 
it was low. When I was on the top of Mount Ventoux, — 
however, nearly 1040 toifes above the level of the fea, I faw — 
it far aboye me. M. Senebier fays, in his letter to Count 

9 . de. 


‘ 


Obfervations on the Fog of 1783. 83 
de Saluces, that it was feen in the Alps at an elevation 
greater than that of Mount Saléve, which rifes 601 toifes 
above the fea. On the 22d of September (1783) I afcended 
the higheft Alps of Dauphiny, to the height of 1660 toifes 
above the fea. (No one has yet been higher in Europe.) The 
fhepherds, who ferved me as guides, all affured me that this 
fog had however paffed over thefe mountains. 

15. The loweft part of the fog was the thickeft and drieft, 
I affured myfelf of this by proceeding from the borders of 
the fea to the fummits of the higheft mountains. 

16. It is probable, according to every account, that this 
fog overfpread almoft all Europe, the iflands of the Mediter- 
ranean, and a part of Africa. It covered the whole Adriatic 
Sea, but extended only to the diftance of 100 leagues on the 
ocean. It was properly a continental fog. 

17. The thunder this year (1783) occafioned great devaf- 
tation. In Provence and Dauphiny alone it killed nearly 
fixty perfons, and a great number of animals. I have found 
no initance of its falling and doing mifchief in places higher 
than 450 toifes abave the level of the fea. - It would be: too 
tedious to infert here the name of every place, which I noted 
down in my journal, where I learned that the thunder fell, 
Jt will be fuficient to relate the moft fingular effects it pro- 
duced, and fuch as may add to our knowledge refpecting the 
nature of thefe terrible meteors, 

According to Pliny, Plutarch, Seneca, &c. the olive, fig- | 
tree, and laurel, are never ftruck by lightning, Porta adopted 
this opinion, which was that of all the ancients. Toaldo. 
fays alfo, it is only thofe trees which contain refin that can 
perhaps efcape the danger of thunder; {uch as the olive-tree, 
laurel, fir, and fome others of the like kind. This, in alk 
probability, is the foundation of the practice, common among 
the populace, of keeping in their houfes, and placing on the 
fummits of fteeples and at the corners of fields, branches of 
alive that have been bleffed, and of burning them in their 
houfes during ftorms. It is poffible, and even probable, that 
trees of this kind may be lefs frequently ftruck by lightning 
than thofe which contain a great deal of aqueous juices ;, but 
} can affert, that thefe prefervatives of the ancients are not 


M 2 equal 


84 Obfervations cn the Fog of 1783. 

equal to our conduétors. On the arft of June the lightning 
burnt the leaves of a fig-tree, and all the bark of an olive- 
tree, in the territory of Sallon; and I learned that the fame 
thing had happened formerly, and that there even had been 
fig-trees and olive-trees fplit and tore to pieces by thunder. 

There is fome kind of thunder, fays Seneca, accompanied 
with a loud report, by which men fall dead, and fome be- 
come ftunned arid lofe their fenfes. In 1783 I faw feveral 
inftances which confirm the truth of this obfervation. At 
Pellifanne in particular, which is fearcely a league from Sal- 
lon, the thunder, attraéted by an iron crofs, killed two. per- 
fons, and deprived feveral others, as it were, of their fenfes. - 
The fame thing happened at Freiffinoufe, in Dauphiny. 

Thunder fometimes, fays Seneca, renders wine frozen and 
congealed, Of the two perfons killed by the thunder at Pel- 
Jifanne, one loft immediately all his natural heat, and the body 
was found extremely cold. Thunder muft fometimes pro- _ 
duce thefe effeéts by occafioning a ftrong and fpeedy evapo- - 
ration. 

Bodies ftruck by thunder, fays Plutarch, do not corrupt: 
dogs and birds do not eat them. This may fometimes be 
the cafe, but I know feveral examples of the contrary*, On 
the day of the fair of Villefranche (July 22d) the thunder 
killed. a mule, which corrupted fo foon that it was found 
neceliary to remove it. About eight or nine years ago, fe- 
veral fheep were killed by lightning on the mountain of Se- 
deron in Provence; and the fhepherds abftained, for a long 
time, from approaching the place, on account of the bad 
fmell which they emitted. On the 1ft of July, about four: 
in the afternoon, the lightning fell at Carpentras on the 
Lazaret, (a place where thofe who died of the plague were’ 
formerly buried,) and fet fire to the wood-work. The fire 
being communicated to feveral quintals of gunpowder, an 
explofion took place, by which five perfons were killed and 
fifteen wounded, The fame flath of lightning traverfed the 
convent of the,Carmelites, and melted part of the feiffars of 
the pr-or: it killed alfo a cow, which was eaten without any 
bad confequence. 


* Sce Mr, Achara’s Experiments, in Philofopbical Magaxine, Vol, 111. p, 51. 
Towards 


Obfervations on the Fog of 1783. 85 
' Towards the end of the month of June, the curé of Efpi- 
noufe, in Provence, ftanding at the door of the church in 
order to exorcife the thunder, was killed, as well as his maid- 
fervant and his clerk. At Mane, in Provence, the bell-ringer 
was killed by it. On the 26th of Anguft the lightning was 
attraéted by the iron ecrofs on the church of Sigoger du Hai, 
in Dauphiny; and, going round it both on the infide and 
outfide, frightened the ringer fo much that he fwore he 
would never return thither again in the time of a ftorm. At 
Pernes, in the Comtat, it overturned a crofs. This crofs, the 
remains of which I faw, was of white calcareous ftone, and 
faftened by a bar of iron to a column of coguilliere ftone* of 
a yellowifh colour, The iron had difappeared; a part of the 
column was fhivered, and blocks of it carried to the ditlance 
of more than twenty-five paces. 

At Aix the thunder dried up a beam, and left in one place 
only the fibrous part. At Freffinoufe, in Dauphiny, it killed, 
two oxen ; deprived a labourer of his fenfes, and carried away 
one of his toe-nails. I muft here remark, that his fhoes 
were fhod with iron. At La Motte du Caife, in Provence, 
it entered at a window, where there was no:iron, and went 
out at the chimney. At Claret it unfaddled an afs without 
doing him any hurt, and carried the packfaddle to a confi- 
derable diftance, In feveral places, and particularly at Ba- 
non in Provence, the lightning tore off the hair from the 
heads of feveral women. At Saint Criftol, in Provence, it 
carried away the half of a Abe body, At Avignon it carried 
away the half of a cat. I had this fact from M. Sauvan, 
who on that day (June 21ft) obferved the ball on the fteeple 
of the Grands Auguftins of Avignon covered with a crown 
of light, which continued three quarters of an hour, and dif+ 
appeared at eleven at night. 

On the 22d of July there fell a great quantity of hail at 
Saint Efprit: it was of a very large fize. A girl, ftruck on 
the head hy a grain of it, applied her hand to the place and 
found her head drefs on fire. 

On the arf of June afcending thunder was Pika at Sallons 


* A kind of ftone mixed with abundance of hells, 


like 


26 Ob fervations on the Fog of 1783: 


like phenomena were obferved the fame day in feveral other 


places. In feveral villages through which I pafled, I was 
thewn a great number of trees firipped of their bark by 
the Chitaliae ; and I remarked that the part of the bark, or 
wood, carried away, was almoft always broad at the bottom 
of the tree, and narrow at the fummit. It would feem as if 
the lightning had met with obftacles, and that it had not 
the fame force when it attacked the higher parts of the tree. 


fn my opinion the thunder which produced thefe effects was \ 


alk afcending; and I often obferved holes at the roots of the 
trees which had been deprived of their bark, I obferved alfo 

that dry land had been lefs firuck with the lightning than 
 moitt Jand, which induces me to believe that the greater part 
of the thunder that year was afcending. 


Il. Thgughts on the Origin of the Eleétric Fog. 


Seyeral philofophers adopted the opinion of the populace,, 
and confidercd this fog as a natural effect of the earthquake 
which laid watte Badly and a part of Calabria, ‘oaldo 
thought that all thefe exhalations were brought from Cala- 
Bria re Sicily by the winds which blew Fins the fouth- 
ward: but this refpe&table philofopher, at the time when 
he wrote, did not know that the fog was almoft’ general 
throughout Eurepe. Befides, the earthquakes in Calabria 
aud a5 took place chiefly im February, and the fog did not 
appear till the middle of June; that is to fay, till more than 
four months after. In my ppimion, then, this fog was not 
eccafioned by the earthquakes of Calabria and Sicily; but 
the fog and thefe earthquakes, as weil as thofe which we are 
aflured took place in Iceland, had a common caufe, which 
produced different effects according as they were modified 
by circumftances and the nature of the places. Let us now 
fearch for this caufe; we fhall find it in the annals of mete- 
erology, and nothing is neceflary, but to diftiaguith it 

I have faid, in another place “, that the conttitution of the 


atmofphere depends chiefly on the nature and form of the 


ground, and that the revolutions of the air are fubjeét to the 
* FJournal de Phyfique, Mars 1782, p. 187- 
TEVOx 


. 


Obferviations on the Fog of 1783. 87 


ferclutions of the earth, over which they have an influence . 


dn their turn.. If we confider the different bodies or fub- 


ftances of which that part of the earth known to us is com- 
poled, we fhall fee that, notwithftariding their apparent reft; 
they all obey, as we may fay, an inteltinal motion; and 
that this motion gives continual rife to new ¢ompofitions 
and combinations, the connection of which efcapes us, but 
which neverthelefs exift. The remains of animals and ve- 
getables flill diftinguithable, and which occupy fo much 
room in our globe; the acids which attack them; the aén- 
form fluids difengaged from them; the metals and pyrites 
brought to perfection, or decompofed ; the fires feparated, or 
collected; the fermentations and efferyvefcences; in 2 word, 
the innumerable decompofitions and recompofitions of all 
the parts of the earth, furnifh abundance of fubtle matter, 
which, by its levity, difengages itfelf at the furface of the 
globe, cannot, in certain circumftances, refilt the gravity of 
the air, and rifes fometimes to the fummit of the atmofphere. 
On the other hand, the rains which fall, moift fogs, and fe- 
veral other caufes, make a part of the water, which des 
taches itielf from the airs to penetrate the earth, and to coms 
bine with the fubftance of thefe exhalations. It is afters 
wards, i part, attracted by the external heat, or repelled by 
the heat of the earth itfelf; but it never returns to the atmo+ 
{phere as pure as it was when it iffued from it. It carries 
with it a great part of that fubtle matter of which I have 
fpoken; and it is-this afterwards which produces thunder, 
and almoft all fiery meteors, There is then a continual 


communication from the earth to the atmofphere, and from, 


the atmofpbere to the earth. The greater part of thefe ex- 
hhalations, in general, is fpecifically heavier than the atmn~ 
fpheric air; and, if they are not impregnated with a certain 
quantity of water, they cannot quit the earth. They muft 


neceflarily be there collected, and accumulate to a greater or 


Jefs depth in the time of great droughts. 

Let us now confult our regifters, and thofe of different ob~ 
fervers, and we fhall fee that there had prevailed, at leaft tor 
mine years, an extreme drought, not only in Europe, but 
alo in Africa and America, This was announced year after 

year 


68 Objervations on the Fog of 1783. 

year by our domicftic as well as foreign gazetiess and we 
may conclude fo from the minute obfervations. of the cele- 
brated Van Swinden, and the tables publifhed by Toaldo,; 
Cotte, Beraud, Besuclin de Romily, &c. Sometimes, in- 
deed, rain took place in one country or other; but in gene- 
tal, till the preceding winter, an extraordinary drought pre- 
vailed. It began about 1774, and in the month of June 1782 
was extremely great in Italy and in our fouthern provinces. 
We experienced at that period a fuffocating heat; the earthy 
as we may fay, feemed to be on fire, and, m the Plain of 
Camargue, fcorched the feet of the reapers to fuch a degree 
that they were obliged at length to walk upon ftraw: feveral 
died of heat with the fickles in their hands, and there were 
a great many fick. Ina word, the drought and heat were fo 
exceflive, that, at two leagues from Sallon, the fpiders, whick 
im general are not venomous, occafioned by their bite violent 
difeafes, which had a great affinity to thofe occafioned by the 
bite of the tarantula. 

In confequence of this great drought, the exhalations of 
the earth, fpecifically heavier than the air, and deprived of 
that humidity which ferves them as a yehicle, remained in 
the bofom of the earth, where they muft have formed im- 
menfe accumulations. ‘The winter of 1782-1783 was rainy, 
particularly in Calabria and Sicily; and the Alps were 
covered with a great deal of fnow. The fpring alfo was in 
general rainy. The water then being filtered into the bowels 
of the earth, was at firft abforbed by the very dry exhalations 
there confined. , This humidity, added to the warmth of the 
fpring, no doubt occafioned effervefcences and fermentations; 
fo that the exhalations, difengaging themfelves with violence, 
in certain places convulfed the earth, as was the cafe in Ca- 
labria and Sicily. In proportion as the water filtered into the 
earth by its own weight, it found new exhalations, which, 


by difengaging themfelves, occafioned new convulfions, but 


lefs confiderable on account of the lefs abundance of thefe 
exhalations. In places where they were heated by their 
mixture, they liquefied ftones, and threw up volcanic iflands, 
asin Iceland. In the laft place, thefe fubtle exhalations 
rifing into the atmofphere from all I parts, with the vapours, 


whielz 


. 


ag 


y On the Converfion of Iron into Caft Steel. 8g 


which ferved them as a vehicle, did not at firft alter its pu- 
rity, being intimately connected with it; but they neverthe- 
Jefs exifted, and produced in its ear regions the multi- 
plied halos, parafelena and parhelia dileke ed that year. The 
- heat increafing, and the earth continuing to furnith exhala- 
tions in proportion to the preceding humidity, thefe were 
communicated to the atmofphere in a manner almoft infen- 
‘fible: but the atmofphere being at length faturated, thefe 
_ exhalations underwent new decompofitions ; ftorms weré 
formed, the atmofphere was cooled, and fuffered to efcape a 
part of thefe exhalations, which fell again towards the earth; 
and in one day Europe was covered with a dry fog *. Local 
circumftances, in regard to moifture, winds, and clouds, 
' exempted certain places from it for fome time. The earth, 
however, continuing to furnifh exhalations, and thefe being 
united to thofe which the atmofphere, as we may fay, had 
depofited, defeending and afcending thunder were feen till 
the exhalations of the earth and the atmofphere were con- 
famed. The atmofphere being gradually purified, and the 
fource of the exhalations eviaulick: the earth ceafed to be 
convulfed, 


; 
} 
x 
Pi 
: 


——s- ye _ isaac nea at 


_ XVI. Report on the Converfion of Soft Iron into Caft Stee] 
by means of the Diamond. Read in the French National 
Anflitute, Thermidor 26, Year7. By C. Guyton ft, 


| aie iit 


aes Clafs. will teehee the account which I gave of the 
7 grand, experiment of the combuftion of the diamond in oxy- 
_ gen gas in the focus of the lens.of Tfchirnhaufen, and the 
y, new facts which I thence deduced refpecting the true nature 
t of the diamond ; plumbago, which is its oxyd in the firft 

degree ; Parti which is its oxyd in the fecond degree; and 
Mt the carbonic acid, which is the produce of its complete oxy- 


° The fame fog, I prefume, took place in America, where shore had 
been great complaint of drought for eight years. It was not feen in the 
“open fea, becaufe it was abforbed by the water: for thig reafon it did not 
" Appear in countries where the fky was over{pread with clouds. | 
From the Annales de- Chemie, No.2. 


PVou. V, N genation, 


Qo On the Converfion of Iron into Caf? Steet 


genation. They fuggefted to our brother, C. Clouet, the 
idea of fearching for a confirmation of a new kind, by trying 
to make foft iron pafs to the ftate of fteel by cementation 
with the diamond, 

It has hitherto been confidered as certiin, that iron does 
not melt but by pafling to the ftate of fteel or caft iron. But 
jn what ftate does the carbon enter into that combination ? 
It might be conjetured, that it is in the ftate of plumbago, 
or oxyd of the firft degree; fince that which is feparated by 
acids exhibits the brilliant blacknefs and incombuftibility 
_ which form its principal charaéters. Hence fome were in- 
clined to conclude, that the carbon entered ipto this union in 
the ftate of an oxjdule; that confequently the carbon em- 
ployed in the cementation of ftee] began by deoxydating it- 
felf to a certain degree. This was even in fome meafure 
proved; as the carhon employed for this operation was in- 
deed found to have a more brilliant afpeét, and nearly refifted 
jncineration, like carbon in a mafs burnt in clofe veffels, 
But if carbon really burns in the cementation of iron, it 
aught to difengage from it oxygen gas. This is a queftion 
which I have endeavoured to refolve by experiment. 

I cemented {mall bits of iron in a porcelain retort, which 
in the preceding operation had received a vitreous coating, 
and which confequently was no longer permeable to air, 
Thefe fragments were all furrounded, on every fide, by char- 
coal of beech pulveriled, and yery dry. The retort was put 
into the reverberating furnace, and a tube connected to it 
and carried under a receiver filled with mercury. There was 
difengaged a quantity of elaftic fluid, compofed of carba- 
ape hydrogenous g eas and carbonic acid gas, the laft’ of 
which was at firlt only O°II in bulk ; ; towards the middle of 
the experiment, 0° 135 and at the.end, 0:15. 

The converfion of iron into fteel being found enly little 
advanced, after three hours and a half expofure to the fire, 
we put the fame iron and the fame carbon again into the 
retort, and expofed it to the heat of a three- blatt- furnace, 
This time there was only a very fmall quantity of gas ; but 
it was ftill carbonated hydrogenous gas mixed with carbonic 


acid Bas, and always with the fame progreffion of the latter; 


re) j which — 


a eS 


Bi 
\ 
4 
-# 
A 
if 
Ni 
‘4 
\ 
i 
y 
3 
c 
be 
Ly 


; 


by Means of the Diamond. §1 
Which made at firft only 0°07 of volume, while thé lait por+ 
tions contained 0°12. The iron on this occafioh was con+ 
verted into fteel, and even the fragments had united by 2 
commencement of fufion, CEN a 
Tt was very probable that a part of the carbonic acid, col- 
Jeéted in this operation, might have been formed at the ex- 
pence of the remaining carbon and with difengaged oxygen ; 
_ but the conftant prefence of the hydrogen only ferved to in 
dicate the difficulty of freeing the carbon entirely from the 
laft portion! of water it contained. I fhall here take occafion 
to obferve, that this expetiment feems not at all reconcile- 
able with the opinion of fome chemifts, that hydrogen has 
more affinity than carbon for oxygeu: an opinion which 
they found on this circumftance, that carbon ig precipitated, 
‘in Volta’s eudiometer, when a mixture of oxygen gas and 
carbonated hydrogen gas is made to detonate; if a quantity 
of oxygen fufficient to acidify the two bafes has not been 
employed. I fay, that this affinity was not exerted in my 
experiment: for it cannot be doubted that the temperature 
was high enough to reproduce water by the union of the 
oxygen and hydrogen; and we can here fee nothing which 
could decide a preference of the oxygen for the carbons _ 

Thefe confiderations feemed to me fufficient to create a 
néw intereft in regard to the experiment propofed by C. 
Clouet. I did not hefitate; therefore, to employ in it one 
of the diamonds preferved in the cabinet of the Polytechnic 
fehool; actording to the leave granted by the Council; being 
perfuaded that if it difappeared in the operation, merely by 
expofure to a high temperature, in contaét with iron, without 

the acceflion.of the air or any other oxygenating fubftance, 
the fact thereby eftablifhed would leave no room to regret 
haying facrificed it. 

‘Citizen Clouet had himfelf prepared 4 fmiall crucible cf 
foft iron, forged on purpofe out of picked heads of nails. Tts 
form was a folid of eight planes. (Plate Il. fig. 3). It was fhut 
by a ftopper of the fame iron well adjufted. (Fig. 4.) 

This crucible was to be placed in a Heffian crucible, fur- 
nifhed with a cover well hated. ‘This was all the appa- 
ratus for the experiment, I cannot give a better idea of the 
: ,N2 refujt 


94 On the Converfion of Iron into Caf Steel 
refult than by the report drawn up by,C. Clouet, Welter, 
~ and Hachette. 


"Report = the iepetiment made at the Polytechnic School, 
_ Thermidor 25, Year 4, refpetting the Converfion of Tron - 
into Steel by the Diamond. 


“* The diamond employed weighed 907 milligrammes. As 
it did not entirely occupy they crucible, we filled it with 
filings of the fame iron as that of which it was formed. The 
crucible was fhut by its iron ftopper, which was forcibly 
thruft home, that as little air as poffible might remain in 
the infide. 


Grammes, 
«© The crucible and ftopper weighed together « 55.8 
« The iron filings which oe the diamond - 2 


** Total weight of the iron furrounding the diamoad 57.8 

«¢ After having cut off the excefs of the ftopper *, the cru 
cible was placed valde! and without the addition of any fur- 
rounding matter, in a very fmall Heffian crucible, ‘and the 
Jatter in a fecond crucible of the fame earth ; but the fpace’ 
between the two latter crucibles was filled silk filiceous fand 
free from all ferruginous particles. In the laft place, the 
large crucible was luted with earth arifing from pounded 
crucibles and unbaked clay, and the whole was expofed 
about an hour to a three-blaft-forge fire. 

‘¢ The whole being cooled, we found, in the interror Hef 
fian crucible, the iron banvamad into an ingot of caft fteel. 
(See fig. 5.) It formed, with the ftopper and filings, but 
one round mafs well terminated, fome few globules excepted, 
which were detached, and which weighed only 884 milli- 
grammes. 


Grammes. — 
“« The ingot of caft fteel weighed “ = 55.500" 
‘© The detached globules A < “ “ 0.884 


 Totat weight of the fteel obtained - = 56.384 


. 


* This portion of the flopper, as well as the remainder of the ingot of 
which the crucible was formed, were fubjeéted to the Clafs for infpeétion, 
in order to afcertain the natwre of the iron employed. b 

‘ “ The | 


by Means of the Diamond. 68 

&* The iron and the diamond weighed, before the opera- 

-tion, 58.707 grammes; from which it follows that there was 

a lofs of iron about 2.423 grammes. This iron had given to 
the Heffian crucible the boot of plumbago. 

<< (Signed) CiovretT, Weiter, HAacwstTre.” 


The fufion of the iron being fo far perfe&t as to thew on 
its furface the rudiments of éhie. moft beautiful cryftallifation, 
it is not poffible to think that any part of the diamond could 
have remained in the infide untouched, or that it was not ia 
the moft intimate ftate of combination. The difference of 
the {pecific gravity oppofes fuch an idea *. 

Thus the diamond difappeared by the affinity which iron 
exercifed on it by the help of the high temperature to which 
they were both expofed, in the fame manner as a metal dif- 
appears in the allay of another metal. 

The diamond, therefore, has furnifhed here the fame prin- 
ciple as carbon, fince the product.of the union has the fame 
properties. ) 

_ The conyverfion into fect j is not doubtful. The ingot hav- 
ing beer polifhed on a lapidary’s wheel, a drop of weak ni- 
trous acid immediately produced a dark-grey {pot, abfolutely 
fike that exhibited on Engiith caft fteel, and on calt fteel 
produced by the procefs of C. Clouet. Thofe who have often 
tried feet by this kind of proof, long ago pointed out by 
Rinmann, had occafion te remark, that the {pot of caft feel, 
though very fenfible, is however lefs black than that of fieel 
made by cenzentation, which depends perhaps on the different 
degree of ozydation of the carbon which they have taken in. 
Explanation of the Figures. 
A, fig. 3, (Plate II.) is the plan of the iron crucible: 
B, a fection of this crucible. C, fig. 4, the ftopper of the 
erucible. D,E, fig. 5, ingot of caft ftecl feen in perfpedtive. 
The fpot formed by the nitric acid on the polithed part is 
feprefented at 2. 


* Some perfons having expreffed a defire to fee the infide of the ingot, 
it was broken en the anvil, which was not cifected without feveral blows 
“From a very large fatimer. Je divided itfelf into two fragments, whict 
vere exhibited at the next fitting: The fracture appeared perfectly uni- 

form, and of the miok beautiful grain. 


AIX. Niath 


{ $4 J 


XIX. Ninth Communication from Dr. THORNTON, Phys 
Jfician to the General Difpenfary, relative to Pneumatic 
Medicine. 


A DISEASED LIVER CURED BY VITAL AIR4 


Tue butler of Colonel Ironfide, .who had been long tefi- 
dent in India, laboured for feveral years under a well-marked 
liver complaint. He had been under the care of Dr. War- 
ten, and other phyficians, without experiencing any effential 
advantage. Colonel Ironfide, as all other means had been 
meffectual, wifhed him to try the vital air. He accordingly 
came under my care, and the fame tonics were employed as 
he had before taken; therefore I afcribe the cure to the vital 
air, which was conjoined with thefe, and which foon com- 
pletely reftored him to health; and he has continued well 
now above a twelvemonth. 


Obfervations. 


When animals placed in puré vital air were deftroyéd by 
fo powerful a ftimulus, Dr. Beddoes found the liver not 
liver-coloured, but of a florid red. We therefore can eafily 
fuppofe it to a& on this organ when given in a moderate 
Way: and as the oxyds of mercury and the nitrous acid, 
which are the beft remedies for this difeafe, ac chiefly from 
their contained oxygen, it is probable that the vital air will 
hereafter be found a fpecifié int this complaint, poffeffing fu- 
perior advantages over both thefe remedies, and will fuper- 
céde them, although it cannot be put up into two-ounce 
phials, the principal objection raifed againft it; for the airs 
can now (which originated from my fuge ican) be confined 
im barrels, and bottled off as eafily as wine: and F muft ob 
ferve, that this patient had a barrel of vital air, containing 
24 gallons, which coft him one guinea, conveyed for him to 
his mafter’s feat in the country, and a tin pneumatic appa- 
ratus for inhaling the medicinal air, which ftood him at the 
low rate of thirty fhillings ; which improvements, I truft, 
will greatly facilitate the “general application of pneumatic. 
medicine, when it wil be fure to find that level its merits 


entitle it to. ie ? 
INTEL- 


{ 95 3 


INTELLIGENCE, 
AND 


MISCELLANEOUS ARTICLES, 


ELECTORAL ACADEMY OF SCIENCES AT MANHEIM,; 


On the 16th of April laft the Electoral Academy of Sci- 
ences at Manheim held a public fitting in commemoration 
of its deceafed founder the Eletor Charles Theodore, who 
died on the 17th of February. On this occafion Mr. M. Col- 
lini, a member of the Society, read a printed oration on ihe 
viciffitudes of the Academy. The moft flourifhing period of 
this inftitution was that between the time of its eftablith- 
ment and the year 1777, when the Palatinate family got pof- 
feffion of Bavarja, and Charles Theodore transferred his re- 
fidence from Manheim to Munich. It was not, however, 
left deftitute of fupport; but its diftance from the cleétoral 
court rendered many things impoffible, which, under other’ 
circumftances, might have been accomplifhed. Still more 
prejudicial to the Academy, as well as the whole Palatjnate, 
was the war which broke out afterwards, between France 
on the one fide, and the German Empire and Aufirig on the 
other. Manheim was bombarded three times, viz. in De- 
gember 1794, November 1795, and January 1798; and as 
often was it neceflary to remove the library of the Academy, 
as well as its papers, &c. to a place of fafety, and to arrange 
them. The fittings and labours of the members were inter= 
rupted 5 the palace, affigned to them for holding their meet- 
ings, was in part burnt; and as the revenues deftined for the 
fupport of the inftitution arife from pofiefl ons on the left 
bank of the Rhine, if thefe remain in the hands of the 
French, it is to be apprehended, that, like many other efta- 
blithments of the fame kind on the right bank of that river, 
which had their revenues on the other fide, it will decline 
pnlefs fupported by the new regent, Among its moft diftin- 

7 gaithed 


96 Sugar from Beet-Roots. 


guifhed members, fince the time of its foundation, may be 
fake Voltaire, ele&ted in 1764; Leffing, and Lalande the 
celebrated French aftronomer. It was eftablifhed in 1763 
according to a plan of the learned Schopflin, and divided 
imto two clafles, the Hittorical and Phyfical; the latter of 
whieh, in the year 1780, was fubdivided into the Phyfical 
(properly fo called) and Meteorological. The collection of 
the papers of the Academy have been publithed in eleven 
volumes quarto, under the title of 4&2 Academie Theodoro- 
Palatine. The Meteorological Obfervations are from 178% 
to 1792, and make twelve volumes quarto, with the title of 
Ephemerides Societatis Meteorologice Palatine. 


SUGAR FROM BEET-ROOTS, 


Profeflor Kfaproth has publifhed the following teftimony 
in regard to fegar procur ed from best-roots; — 

i Having, i in confequence of a requeft by Mr, Achard, 
that I would examine his procefs for making fugar from 
beet-roots, and communicate to him the refult, convinced 
myfelf, by repeated experiments; of the abundance of fae- 
charine matter in thefe roots, that I might afeertain the 
proportion with more accuracy, I made the following expe- 
riment :—Twenty-five freth roots, which weighed 32; poundg _ 
after they had been feraped and the tops cut off, were put 
inte a perforated tin veflel, and the juice was expreffed by a 
proper apparatus. The juice obtained weighed 19} pounds, 
‘The fqueezed refiduum was put into a tin kettle with boiling 
water, and, after ftanding an hour, was preffed alfo. This 
extract was added to the juice; both were boiled to a fyrap, 
and ftvained through a woollen cloth; after which the fyrup 
teas put into a parcelain eapfule, and evaporated gradually 
over a flow fire to complete drynefs. The raw fugar ob- 
ae and which T put mto a fealed glafs, amounted te twa 
pounds twélve ounces. 

“ That 25 roots, or 323% pounds of beets, produced twa 
pounds twelye ounces of fugar, is hereby certified, as witnefs 
wy hand, Martin Henry Kiaprotrs,” 


Berlin, sxth January 1799°” 


A letter 


~ 


indigo Refin—Converfion of Tron into Steel. 97 


A letter from Berlin, dated September 28, ftates, that the 
eommiffion appointed by his Pruffian majefty, to examine 
Achatd and Klaproth’s procefs for making fugar from beet- 
roots, have finifhed their report on that fubject: The refult 
is, that 1500 pounds of beet-rvot gave 398 pounds of very 
agreeable fyrup, which produced 57 pounds of powder-fugar 
of a white colour; and proper for ufe without being any far- 
ther refined. 

INDIGO RESIN. 


Profeffor Brugnatelli, of Pavia, has lately anriounced, that, 
by treating idigd with the nitrous acid, one may obtain a 
large quantity of a peculiar refin, which he calls Refina in- 
digofera. An ounce of indigo diftilled with four ounces of 
the nitrous acid, left a thick mafs, in which he found a con- 
crete fubftance ei red colour, which, when feparated, had 
all the properties of refin: it ae half an ounce. This 
tefin diffolved very eafily in alcohol, which acquired from it 
a dark red colour. Waiter decompofed this folution imme- 
diately, and produced a yellow precipitate. This tin@ure 
communicated its colour to paper and” linen, and gave ita 
beautiful and durable yellow dye. It communicated the fame 
colour to the fkin and the nails: the former retained its co- 


Jour for a long time. This refin has a yery bitter, aftringent, 


and difagreeable tafte;. but no fenfible fmell. On glowing 
coals it melts and burns with a flame, and at the fame time 
emits a fharp difagreeable {mell. 


CONVERSION OF IRON INTO STEEL. 


Our valued correfpondent Mr. Muthet, of the Clyde Trot- 
Works, has examined and repeated C: Clouet’s procefs with 
confiderable fuccefs. The experience of Mr. Mufhet in fimi- 
lar procefles rendered him well quatified for the inveftigation, 
and the refult has been what we fhould have promifed from 
our knowledge of his abilities and accuracy. Mr. Mufhet, 
inftead of experiencing any lofs in the weight of iron em- 
ployed, has uniformly obtained the fame” increafé gained in 
the large way of manufaéture by the common procels of ce- 
mentation with charcoal, vz. from ;5 to 7th. However, 
in varying the experiments of the French chemifts, he has 

Vou. VY. v met 


98 Improved Writing Ink.—Manganefe in Vegetabless 


met with phenomena that foree him to draw very different con 
clufions from them, and to reject the idea of the carbon being 
furnifhed by the decompofition of the carbonic acid; for, in 
fome experiments, he employed for the conealaniae calca- 
reous earth, previoutly deprived of its acid, and excluded the 
contaét of external air, and the refult was caft fteel. Thefe 
experiments. were performed } in crucibles made of Sturbridge. 
clay, without any mixture. Superior effeéts, however, were 
produced-in half the time, by prefenting carbon, in a com- 
paratively deoxydated ftate, in crucibles varioufly compound- 
ed. Some curious queftions naturally arife from the refult. 
of thefe experiments; efpecially from the firft, as, Whence 
comes the carbon? But as Mr. Mufhet has promifed, in 
fome future Number, to Jay his experiments on this inte- 
refting fubject before the public, our philofophical readers 
will then be better enabled’ to enter upon the inveftigation. 


FMPROVED WRITING INK. 


©. Van Mons has applied the difcoveries of Prouft to the 
preparation of common writing ink. He has found that the 
fulphat of iron, calcined to whitenefs, always gives a moft 
beautiful black precipitate. By the following mixture he ob- 
tained excellent ink :—Galls, 4 ozs.; fulphat of iron, calcined 
to whitenefs, 2 ozs.; and two pints of water. The whole 
muft be left ta infufe cold’ for 24 hours; then add gum 
Arabic ro drachiis, and’ preferve it im a ftone jar, either’ 
open,. or covered merely with paper. 


MANGANESE IN VEGETABLES. 


M. Prouft has lately publithed. the following fhort way of 
proving the prefence of manganefe im fuch vegetable produc- 
tions as contain any ;. which has this to recommend it, that 
it is fhorter and more effeCtual than that of Scheele. Put in 
the procefs diftilled vinegar (enaploying heat) on well-wafhed 
afhes, without attempting, however,.to extract from them all 
that they are capable of yielding to the acid. The liquor then 
contains Oxyd of manganefe, lime, and magnefia. Try it by the 
prufliat of pot-afh, and it gives a precipitate of the colour of 
peach blofloms, which, treated by the. blow-pipe in the ufual 

manner, 


BY LIE, omete "an 


i] 


¥ 
il 
y 
' 
‘< 
a 
3 
4 
& 
4 


< 


er ee a a 


Stuffs for Dyeing. —Yellow Dye. 99 


manner, gives conftantly the colour which denotes the pre- 
fence of that oxyd. This precipitate is not without a little 
iron, which it receives, as I believe, from the pruffiat of pote 
afh. Then put nitric acid over the refiduum of the afhes, 
and it will take from them the iron, which may be proved 
alfo by the pruffiat. Then fearch for the different earths, 
which may be difcoyered by the common means.- The 
afhes of the pine, calendula, vine, green oak, and fig-tree, 
contain manganefe. The afhes of the fig-tree are almoft all 
filiceous; the afhes of barilla do not contain an atom of it, 
but iron in great quantity, magnefia, &c. 


PREPARATION OF STUFFS FOR DYEING. 


A letter from Van Mons to Brugnatelli, printed in the 
92d number of the Annales de Chimie, contains a ufeful 
hint-on this fubjeét. He expreffes himtelf as follows: 

** The memoir, read by Giobert tothe Academy of Turin 
on the animalifation of flax and cotton, induces me to men- 
tion a circumftance which ought to have led me to the dif- 
cavery of this animalifation long ago, had I paid proper at- 
tention to it at the time, I had. caufed fome oyfter-fhells to 
be boiled with pot-afh.and lime, in order to whiten them for 
fome pharmaceutical purpofes 5 and I employed _the ley pro- 
duced by that operation, to bleach the linen cloths ufed to 
firain the decoctions. My pupils made me afterwards ob- 
ferve, that thefe pieces of cloth were ftrongly dyed when any 
fubftances were paffed through them, the colour in which 
might have been carried off by merely wathing in cold water.” 


YELLOW DYE FROM 4 SPECIES OF MUSHROOM, 


Among the different kinds of mufhrooms, capable of pro- 
ducing tively and durable dyes, none is more worthy of no- 
tice than the Boletus birfutus of Bulliard, from which C, 
Lafteyrie has extracted 4 bright, fhining, and very durable 
yellow dye. This pretty large mufhroom grows commonly 
on walnut and apple-trees. Its colouring-matter-is con- 
tained in abundance, not only in the tubular part, but alfo 
ip the parenchyma of the body of the muthroom, In order 

O32 to 


\ 
100 Natural Hiftory, 


to extract it the mufhroom is pounded in a mortar, and the 
liquor | thence obtained is boiled for a quarter of an hour in 
water. ‘’ An ounce of liquor is fufficient to communicate co- 
louring-matter to fix pounds of water. When the liquor has 
been firained, the fluff to be dyed is put into it, and boiled 
for a quarter ofan hour. All kinds of ftuff receive this co- 
lour and retain it, but on lineh and cotton it is lefs bright, 
This colour may be modified, in a very agreeable manner, by 
the effect of mordants, 

The procefs fucceeded beft on filk. When this fubftance, 
after being dyed,-is made to pafs through a bath of foft foap; 
it acquires a fhining golden-yellow eolours which has a per- 
fe& refemblance to the yellow of that filk employed to imi- 
tate embroidery in gold, and which has hitherto.been brought 
- from ‘China and fold at a dear rate, as the method of dyeing 
jt is unknown in Europe. The yellow colour extra@ted fromr 
this nfuflroom maybe employed alfo with advantage for 
painting in water-colours as well as in oil. 


NATURAL HISTORY. 

The two following articles on the Friendfhip and the Sa- 
gacity of Birds, by Mr. Simpfon of New-York, we copy 
from the Medical Repofitory, 5 avaluable work publifhed in 

"America :—~ 

«* Mr. Myers, a brother-in-law of mine, moving from 
Wilton to Philadelphia, defired me tg fend for a large tur- 
key-cock and hen, and a pair of bantams, which had been 
a long time in his yard, and which the family did not choofe 
to have killed. Accordingly, after"his departure, I had them 
brought home, and put with fome other poultry that were 
then creer in my yard. Some time after, as I was feed- 
ing the poultry from the barn-door, a large hawk turned the 

barn, and fuddenly made a pitch at the bantam hen: fhe 
immediately gave the alarm, bya noife which they generally 
make on fuch occafions; when the large turkey-cock, who 


was about two yards diftance, and who I prefumed faw the ~ 


‘hawk’s intentions, and the imminent danger of his old ac- 
quaintance, flew at the hawk with fuch violence, and gave — 
him fuch a fevere firoke with his fpurs ashe was going to © 

fiz ; 


Natural Hi iftory.— Deaths. LOE 


_ feize his prey, as to knock him from the hen to a confider- 


able diftance; and the timely aid of this faithful auxiliary, 
the turkey-cock, faved the bantam from being devoured by 
the hawk.” 

During my refidence at Wilton, early one morning I heard 
a noife from a couple of martins, who were jumping from 


tree to tree adjoining my dwelling. They made feveral at-. 


tempts to get in a box or cage fixed againft the houfe, which 
they had before occupied; but they always appeared to fiy 
from it with the greateft dread, and repeated thofe loud cries 
which firft drew my attention. Curiofity led me to watch 
their motions. After fome time a {mall wren came from the 


box or cage, and perched on a tree near it, when her fhrill, 
notes feemed to amaze her antagonifts. After fome time fhe, 


flew away. The martins took this opportunity of returning 
to their cage: but their ffay was fhort. Their diminutive 
adverfary returned, and made them fly with the greateft pre- 
cipitation, They continued manceuvring in this way the 
whole day, and I believe the wren kept poffeffion during the 
night. The following morning, on the wren’s quitting the 
cage, the martins immediately returned, took pofleflion of 
their manfion, broke up their own neft, which confifted of 
twigs of different fizes; went to work, and with more indu- 
firy and ingenuity than I fuppofed they poffeffed, they foon 
barricaded their doors. The wren returned, but could not 


re-enter. She made attempts to ftorm the works, but did 


not fucceed.—I wil] not prefume to {ay that the martins fol- 
Jowed our modern maxim, and carried with them a fuffi- 
ciency of food to fuftain a fiege, or that they made ule of the: 
abftinence which neceflity fometimes, during a long and bad 
fiorm, might probably occafion; but they perfevered for 
near two days, to defend the entrance within the, barricado; 


and the wren, finding fhe could not force an entry, raifed the. 


fiege, quitted her intentions, and left the martins in, quiet 
polleffion without further moleftation, 


DEATHS, 
On Friday, the 11th of October, Samuel More, Efy. w ee 
for many years pat filled the office of Secretary to the Society 
7 | for 


~~ a - Bond 


AS Ug <2 as 


102 sc Deaths, 

for the Encouragement of Arts, Manufactures, and Com~ 
merce. The affiduity and ability with which he difcharged 
the duties of the office he held, for that refpectable Inftitation, 
will make it difficult to find another to fill it who may be as 
well qualified. 

A few weeks ago, at New-York, Dr. Perkins, inventor of 
the metallic traCtors. He had gone thither, from his ufual 
place of refidence in Connecticut, to affift his brother prac- 
titioners in endeavouring to arreft the progrefs of the yellow 
fever, with which that city has been again vifited, and eaught 
the infection, which carried him off. 

In the Philofophical Magazine for April laft we armounced 
the death of that celebr ated naturalift Spallanzani on the 11th 
of February. It appears, however, that he died on the r7ths 
and, as every thing that relates to the laft moments of emi- 
nent men is interefting, we hope our readers will not be dif- . 
pleafed with us for adding the following particulars :—On the 
evening of the roth he was feized with an apoplectie fit, the 
confequence of a neglected ftrangury. Profeflors Brera and 
Scarpa, who were called im to vifit him, immediately faw that» 
all medical aid would be ufelefs; for, on infpeéting his urine, 
it was found that the bladder was ina flate of gangrene. 
‘They however ordered him fuch medicimes and treatment as 
they thought could be of any feryice. On the 12th the af- 
feétion in the left arm and the lips difappeared. On the 13th 
he recovered the full ufe of his fenfes ; found himfelf much 
betier; and, without apprehending death, attended to his 
literary and domeftic concerns. Early on the morning of 
the 17th he was attacked by a general debility, accompanied 
with a diarrhoea entirely enblicnaiitives The two profeffors 
then told him, that this day would be the laft of his life; an 
information which Spallanzani received with the greateft 
firmnefs of mind. Towards noon he embraced his friends, 
the two profeffors, and particularly his brother, who had 
come exprefs to Pavia from Scandiano, in the duchy of Mo- 
dena; took the moft affeGtionate leave of them, and exactly 
at 11 o’clock breathed his laft in their arms, The opinion - 
of the phyficians refpe€ting his difeafe was confirmed by the 
opening of his hody, A hiftory of it has been published by 

Profefloy 


/ 


Deaths. “104 


Profeffor Brera, whe was two years phyfician to this eminent 
naturalift. Two monuments are to be erected at the public 
expence to his memory; one in the Pantheon of Milan, and 
another within the precinéts of the Univerfity of Pavia. 

In the fame Number of the Philofophical Magazine we an- 
nounced alfo the death of Profeflor Lichtenberg, of Gottingen, 
on the 24th of February. Since that period a fmall work 
_ has appeared at Gottingen under the title of, Elogium Georgit 
Chriflophor: Lichtenberg, in conceffu Soc. Reg. Scientiarum re-= 
citavit A. G. Kajiner, 207°. d. Ap. 1799; from which we 
extract the following particulars :—Profeflor Lichtenberg was 
born on the 1ft of July 1744, at Oberamftadt, in Heffe Darm- 

ftadt. He was of a weakly conftitution from his birth, and 
applied himfelf very early to the mathematics and natural 
hiftory, in which he was greatly affifted by his two brothers, 
who were older. In the year 1763 he went to Gottingen, 
where he became the pupil and friend of Kaftner and Meitter, 
and attended the Lectures of the other profeffors. In con- 
_junétion with Erxleben he made fome obfervations on the 
earthquake of 4767; and remarked, in particular, that the 
_ fhock continued fix feconds ; while others, not accuftomed to 
“tathematical accuracy, extended its duration to a whole mi- 
mute. He delineated the courfes of the comets which had 
been oblerved; and it is remarked, that he poffeffed a great 
deal of patience for works of this kind. Profeffor Kafiner 
has now in his pofleflion a drawing by him, of the face of the 
“moon, where the fpots are marked in the order in which they 
enter the earth’s fhadow during eclipfes. In the year 1770 
he was invited to Gieflen; but he preferred Gottingen, where 
hie was appointed Profeffor Extraordinary. In the years 1772 
and 1773 he was commiflioned to determine, from aftrono- 
‘thical obfervations, the pofition of various places in his Bri- 
tannic Majefiy’s German Siates; and for this purpofe was 
fupplied, at the king’s expence, with a quadrant by Siffon. 
‘Tt 1776 he laid the ‘refult of this labour before the Royal 
Society, of which he had been elected a member two years 
before. -As repeated wifhes had been expreffed that Mayer's 
- Manufcripts might be publithed, Profeffor Kaftner put them 
fgpte the hands of Lichtenberg, who, affifted by Dietrich, 
publithed 


Wie yw 


£64 Deaths, 

publithed the firft volume, in 1775, with a typographic ele. 
gance which had been before unknown in Germany. Want 
of leifure prevented him from editing a fecond. Lichten- 
berg was twice in England ; the firft time im 1770, and agairt 
in 1774. Inthe year 1777, after Erxleben’s death, he ftudi- 
ed natural. philofophy, in the introduction to that feience 
written by his predeceffor; the four. laft editions of which 
were publifhed under his infpection, but always with addi- 


_ tions by himfelf. On this occafion he made a colle&tion of | 


philofophical inftruments, which afterwards beeame the pro- 
perty of the Univerfity. Among the new experiments, which 
were peculiarly Lichtenberg’s own, isthat refpecting the figures 
formed by pounded refin on the ele&trophore, by which he 
examined and traced out the nature and progrefs of the elec- 
tric fuid in a new manner, and communicated the refult of 
his refearches in two papers, read before the Royal Society 
in 1777 and 1778. Profeffor Lichtenberg had a very exten= 
five correfpondence, which enabled him to commanicate te 
the Society a variety of ufeful intelligetice. He propofed, al- 
ternately with Kaftner, the prize queftions of the mathema~ 
tical clafs, and was the author of the Jaft for the prefent year. 
refpeCting the motion of fteam in conduétors of a given kind. 

In the year 1780 he began, in conjunétion with the late 
J. R. Forfter, the Gottingen Magazine, fix numbers of which 


appeared annually, till 1785, when it was dropped with the © 


firft number of that year. In the Gottingen Pocket Calen- 
dar, of which he was the editor for many years, he publithed 


various articles equally ufeful and agreeable. Among thefe — 
was an account of Hogarth’s fatyrical prints, accompanied — 
with engravings. The large account of thefe prints, witha — 
commentary, is well known. As Profeflor Lichtenberg’s ~ : 


complaints returned regularly every year, the laft attack was 
at firft not confidered dangerous ; but an inflammation of the 
lungs taking place, he was orice off on the 24th ‘of Febru« 
ary, as before flated. 


i 


ne sim oe —— = : 
ar =P a a ae eae 


a 


t 


| 


THE 


PHILOSOPHICAL MAGAZINE. 


NOVEMBER 1799. 


I. Obfervations on the irc awel Reflux of the Atmofphere. 


By the Abbe Mann*. 


As the general power of attraction or gravity extends to 


all bodies within the fphere of its action; and as the atmo- 
{phere of our earth confifts not only of heavy, but alfo of 
_ moveable and elaftic parts, which revolve around a common 


axis like the water of the ocean, it neceffarily follows that 


the atmofphere muft be affected by the fame phyfical caufes 
which produce the flux and reflux of the fea. This confe- 
quence is fo immediate and neceffary that it is not poffible 


to doubt'it: the queftion therefore will not be the exiftence 


of a flux and reflux, but merely refpecting their extent. 


Many philofophers have afferted, on grounds which do not 
ear to have much validity, that the “flux and reflux of the 


atmofphere amount to no more than thofe of the ocean, that 


is, eight feet. According to thejr opinion, a fea of water, 


‘air, or quickfilver, w tina’ be raifed to about the fame height 
by the effeéts of the fun and moon, and acquire from them 
nearly the fame movement. Thofe who {peak in this man- 
‘mer, muft entirely overlook the nature of elaftic fluids; for 


"it may eafily be conceived that, with the fame power of at- 


* From the Tran/adtions of the Academy of Sciences at Bruffels, Vol. 1V, 
Vou. Y. P traction, 


the regular winds, and other phenomena which depend on 
‘them. 


106 Obfervations on the Flux and Reflux 


traction, the movement of an elaftic fluid would be totally 
different ffom that of a non-elaftic. Other philofophers, 
not neglecting this confideration, have believed that the 
caufes which produce the movement of the waters of the 
ocean can occafion a much greater in the aérial mafs of the 
atmofphere, and muft have a very great {hare in producing 


D’Alembert has calculated, from the theory of general 
gravitation, thofe movements which muft be produced in 
the atmofphere by the effects of the fun and moon. He 
found that from this influence a continual eaft-wind muft 
arife at the equator, and that, in the temperate zones, nat 
far from the tropics, it muft be converted into a weft-wind ; 
that on account, however, of many local circumftances, and 
other impediments which come iy the way, it cannot al- 
ways continue in the fame direction; and that the variations 
in the ftate of the barometer, which thence arife, muft be 
very inconfiderable, and almoft imperceptible, 

Bacon, Gaffendi, Defchales, Goad, Dampier, Halley, and — 
others who have written on the wind, all unanimoufly ob- 4q 
ferve, that the periods of the year moft expofed to it are the © 
two equinoxes: that florms are moft frequent at the times 
ef new and full moon, and particularly thofe which happen ~ 
near the equinoxes: that at periods, otherwife calm, a fmall — 
breeze always takes place at high water; and that a fmall 
moyement in the atmofphere- is each time perceived a little 
after noon and midnight. Now, as moft of thefe circum- 
ftances haye a great refemblance to thofe which cua A 
the flux and we of the fea, and take place at the f 4 
time; and as in this refpe&t the movement of water and Ra 
atmofphere 1 is the fame, according to Newton’s rule, that | 5 
natural effects of the like kind mutt be produced by the fame 
caufes *, both may be deduced from the fame fource. - 

From, this it appears that theory and experience coincide ~ 
to eftablith the exiftence of an atmofpheric flux and reflux, © 
and of the regular and very perceptible effects which they ~ 
produce. ‘Nothing therefare is neceflary but to deduce their — 


* Effectuum naturaliym ejufdem generis exdem aflignande funt caufla. 
phenomena — 


Gf tbe Atmofpbere. toF 
phenonieria and extent from the well-known ptoperties of 
elaftic fluids. For this purpofe we muft have before our eyes 
the following principles of aérometry, to be found in moft 
elementary books :=—— 

1. The elafticity of fluids is in the inverfe ratio of their 
denfity, and in the dire& ratio of their rarity. Thus air is 
more elaftic than water; light more elaftic than air; and 
ether than light. This is one of the principles ‘of New- 
ton *. 

2. The force of elafticity of the air expands and contracts 
itfelf in the direét ratio of the weight with which it 1s loaded, 
and diffufes itfelf in the inverfe ratio of the force by which it 
is comprefled ‘ie 

3. The air is rarefied, or diffufes itfelf, in the direct ratio of 
the quantity of heat which aéts upon it f. 

4. The air, as well as all fluids in general, has a tendency 
to put itfelf in equilibrium, and does not reft until it has 
obtained it §. 

It now follows, from thefe principles, that every thing 

_ which increafes the weight of the atmofphere, and preffes 
_ the air more in one place than another near it, muft occa- 
 fion the air to ruth from the former to the latter, where it is 
lighter: and, on the other hand, every thing that leffens the 
"gravity of the atmofphere, and increafes or rarefies the air, 
‘and makes it lighter than in the neighbouring parts, muft 
occafion the air to ruth in from all fides to thofe parts 5 and 
‘this continues in each cafe till the equilibrium is reftored, 
and reft again effetted. This is the principal caufe of the ‘ 
‘origin of wind. But, as a pendulum put in motion does not 
mediately reft when it has come to a perpendicular direc- 
n, but obtains reft after making fome {mall vibrations; in 
the fame manner, the currents of air, from the places where 
_ the air is more preffed to that where it is Jefs fo, will ruth be- 
yond the boundaries of the equilibrium, from which they 
will again fly back, and at length obtain reft after feveral 
“undulations. As this takes place in all ‘fluids, it is more 


i 


a 6 
» * Princip. in fine, p. 530, edit. 1726, et quaft. 21, 22, inf fine optices. — 
_ + Wolf Elem. Aérom. § 72—77- t Ibid, § 146. § Ibid, 
§36—44. Ad 

Pa, peculiarly 


108 Odbjervations on the Flux and Reflux 


peculiarly common to elaflic fluids; and it is obferyed, ae~ 
cording to thefe principles, that the winds during ftorms 
change their courfe, and blow exacétly from thofe points to 
which the current was before directed. 

. The fpecific gravity of the air is 800 times lefs than that 
of water, and its elafticity is infinitely greater. The attrac- 
tive power of the fun and moon leffens the gravity and pref- 
fure of the atmofphere towards the earth, as it draws it to- 
wards thefe bodies in the fame manner as it does the water 
of the ocean. But this power of attraction does not extend 
the water of the ocean, which is deftitute of elafticity, as it 
does the whole mafs of the atmofphere (poffeffed of it, and 
expofed to the action of this power) in the ratio of the de- 
creafe of gravity, and of the preffure of the atmofphere to-— 
wards the earth. Adopting, therefore, the inadmiffible fup- 
pofition, that-water, air, and quickfilver would be raifed to 
nearly the fame height, and be moved in the fame manner 
by the attractive force of the fun and moon; this much at 
any rate is proved, that the extenfion of the air, in proportion 
to the leflening of, the gravity of the atmofphere towards the 
earth, muft always take place, and produce a confiderable 
atmofpheric flux, while this effect cannot occur in regard to 
the flux of the ocean, It is certain that fluids are more or — 
lefs fubjeét to the effects of any power acting upon them, ~ 

-according as they have more or lefs mobility, which is in — 
the direct ratio of their rarity and elafticity. Now, as air 
poffeffes thefe properties in a degree 800 times greater than 
water, the flux of the atmafphere muft very perceptibly ex- — 
ceed in magnitude that of water. This, therefore, is a fe- 
cond certain argument againft thofe who pretend that the — 
flux and reflux: of the atmofphere are fimilar to thofe of the | F 
ocean. Not only niuft the attractive power of the fun and 
moon, on account of the greater elafticity and mobility of — 
the air compared with water, produce a greater effect on the © 
atmofphere than on the ocean, but the component parts of 
the atmofphere, as they are nearer the moon by about a 
ninetieth part of the femidiameter of the earth, muft be ~ 
"more ftrongly attraGted than the watery particles of the 
-gcean; in the fame manner as thofe which are go degrees _ 
diftant 


me ee 


of the Atmo/phere. 209 


diftant from the place where the moon is vertical, muft oc~ 
cafion a greater preffure on the earth on account of the 
greater obliquity of the attraction, and this in proportion to 
the greater height of the atmofphere above that of the fea. 
This is the third phyfical caufe which makes the flux and 
reflux of the atmofphere more confiderable than that of the 
ocean, To this we may add the immenfe {pace occupied by 
the atmofphere in comparifon of the ocean ; for if the whole 
globe were covered with water, this general ocean would not — 
occupy the fiftieth part of the fpace actually filled by the at- 
mofphere; and in my opinion the extenfion effected in elaftic 
fluids, by the fame power of attraction, is in proportion to 
their maffes. Suppofing this to be the cafe, the flux of air 
in an atmofphere of ten miles height, would be much more 
confiderable than in another amounting to only a tenth part 
of that height: though this difference cannot take place in 
the flux and reflux of the ocean, becaufe water is deftitute of 
elafticity. Befides, lands, iflands, ftraits, bays, the fituation 


_of the coafts, fand-banks, fhoals, &c. throw a great many 


impediments in the way of the water in regard to its mo- 
tion; whereas the atmofphere, which rifes to a height ten or 
twelve times greater than the fummits of the higheft moun- 
tains, is in no manner prevented from moving according to 
the effects of the power of attraction, unlefs fomething very 
particular takes place in its loweft ftrata. It is more than 
probable that each of thefe caufes contributes its part to make 
the movement of the atmofphere far more ronficérable than 
that of the ocean. 

It. is therefore certain that the united effects of the attrac- 


_ tion of the fun and moon on the atmofphere of the earth 
~ mutt raife and extend it in the inverfe ratio of the fquare of 


the diftance fo as to make it aflume the form of a lengthened 


fpheroid, the greater diameter of which, from the fame 


grounds and with the fame variations as the aqueous fphe- 
roid, muft nearly follow the direction of the line of attrac- 
tion. 


Befides, the heat of the fun, which has no fenfible influ- 


_ence in raifing or extending the water of the ocean, will pro- 


duce an effect on that part of the atmofphere ¢xpofed. to , its 
rays 


ii6 Obfervations on thé Flu and Reflix 

rays by heating and rarefying it, in the ratio of its flrencth} 
according to the third of the Befode ahewniondd principles: 
That part, therefore, of the atmofphere which is gradually 
turned towards the fun, muft extend in proportion to the de- 
gree of heat which acts upon it; and rife above the reft; and 
this atmofpheric {welling will conftantly follow the apparent 
daily courfe of the fun: The moon, on the other hand, has 
no power to produce or change this phenomenon; becaufe; 
in all the experiments hitherto” made to collet aiid eoticens 
trate its rays, thefmalleit degree of heat has never been ie 
eerved. 

As there are therefore two different caufes, viz. the icihineth 
attraction of the fan and moon, and the heat of the fun 
alone; by which the latter, except at the time of the fyze+ 
gtes, when they both act in the fame direction upon oné 
- point, has a particular influence on the atmofphere of the 
earth independent on that of the former, it thence follows 
that they will produce three different fluxes every day: Two 
of them-arife from the attractive power of the fun and moon, 
and in their formation, direction, and movement, are per= 
feGtly fimilar to thofe produced 1 in the ocean from the fame 
caufes. The third, however, is produced by the heat of the 
fun alone; and its prominent parts will always be in’ that 
parallel through which the fun pafles in the courfe of his 
daily movement, .and will ome. follow that luminary, 
from parallel to parallel; at a fmall diftance. The two firft 
I thall call attraéion-tides, the third heat-tides. 

The tides of attraction, like thofe of the ocean, and froni 
the like grounds, have at the fame time, at two oppofite ends 
of the globe, projecting parts, and thefe lie almoft in that 
line which might be drawn from the centre of the earth to 
‘that of the moon. The heat-tides,-on the other hand, can 
take place only on one point of the globe; that is, m the 
point to which the fun is vertical. Their projecting part 
will be dire&ted towards that niesnihion and nearly follows 
its movement. 

In regard to the effe&s of thefe atmofpheric tides, they 
depend’on the natural ftate of the aérial fluid, and om its’ 
reft, which confifts in an equilibrium of all its parts. When 

this 


of the Atmofphere. ~ viz 


this equilibrium is deftroyed, the atmofphere -returns to its 
former ftate as. foon as the caufe of this derangement is re- 
moved. If this equilibrium is by any caufe deftroyed in any 
one place, a movement muft naturally follow from all fides, 
and continue until the equilibrium is again reftored; and in 
this we may difcover the principal caufe of the origin of 
wind. Every thing, therefore, which can derange the equi- 
librium of the atmofphere in any manner, muft be reckoned 
among thofe caufes which give rife to wind: fuch as the flux 
and reflux of the atmofphere, occafioned by attraGtion and 
heat; all other rarefaGtion of the air by heat; or the con- 
denfation of it by cold, &c.; the letting loofe of vapours by 
fermentation and evaporation into the atmofphere; the erup- 
tion from the bofom of the earth and afcent of elaftic vapours, 
volcanoes, earthquakes, and perhaps other caufes not fo evi- 
dent, and therefore lefs known. The exceedingly variable 
diregtions of the wind depend on the nature of the countries 
from which they blow; and, in particular, on mountains, 
forefts, rivérs, marfhes, lakes. In a word, every thing that 


‘ean oppofe or favour the free movement of the aérial fluid 
‘has an influence on the dire€tion of the wind. 


Among all thofe caufes which derange the equilibrium of 
the atmofphere, and contribute to the production of wind, 


. the principal and moft uniform is the rarefaction and con- 


denfation of the air, Both are the immediate effe&t of the 
different atmofpheric tides. The regular courfe of thefe tides 
from eaft to weft, in confequence of that of the fun and 
‘moon, muft produce a continual eaft wind; which is how- 
ever exceedingly weak, but continues without interruption, 
and prevails only in the immenfe feas of the Torrid zone, 
though with moft regularity in the Pacific ocean, on account 
of its va(t extent, The comprefied parts of the atmofphere 
in the neighbourhood ruth towards thofe moft rarefied by the 
atmofpheric tides, and follow them alfo.in their regular pro- 
grefs from eaft to weft. The parts of the atmofphere, how- 
ever, in the weft, will have a much lefs, or perhaps no move-~ 


ment towards thofe which proceed from the eaft, on account 


pf the atmofpheric flux moving towards them: at afy rate, 
the motion from eaft to weft will exceed that fmall motion 
; 9 from 


412 Obfervations on the Flux and Reflux 


from weft to eaft, and therefore produce a continual eaft 

wind in the parallel of the atmofpheric tide. A wind alfo 

will proceed from the north or fonth of this parallel, in an 

oblique direction north and fouth, to the diftance of about 

thirty degrees on each fide of the equator. In both the tem- 

perate zones the regular winds muft blow from weft to eaft 

within thefe boundaries, as they incline towards the parallel 

of the atmofpheric tide, and again reftore the equilibrium of 
the atmofphere, which has been rarefied by the continual 

movement of the aérial tides. Thefe confequences, deduced 

from theory, coincide perfeétly with the courfe of the wind 
in the ocean. At land, and on confined feas, many other 

caufes exift which contribute to change the regular direGtion 
of the winds, and to make them variable. 

On the coafts, in the torrid zone, the wind blows for the 
moft part from the fea towards the land. The reafon of this 
is evident. The reflected rays of the fun, and other caufes, 
heat and rarefy the air at land much more than at fea; and 
the direGtion of the wind always proceeds towards the rare- 
fied part of the atmofphere. The places where the laf men- 
tioned winds feparate *themfelves from the regular winds, 
“muft be abfolutely calm. All this is confirmed by experi- 
ence throughout the whole torrid 20 and particulatly oa 
the coa{t of Guinea. 

Befides the determination i courfe of the winds in 
confequence of the atmofpherit flux and reflux, there are 
an immenfe number of local and accidental caufes whieh 
have an influence on the creation and direction of the winds. 
One of the leaft irregular is the preffure < and gravity of the 
atmofphere in the fricid zones, which mutt occafion a con- 
tinued movement of ‘the air towards the more rarefied parts, 
and at the fame time a wind from ‘the poles towards the 
equator. As foon, however, as this continual wind enters 
the temperate zones, its direction will be overcome and de-. 
ranged by other local caufes: an examination, however, af 
thofe winds not arifing from the atmolpheric tides, does nat 
fall within the plan of this effay. 

Thofe winds, on the other hand, which ongule blow 
at fun-rife and fun-fet, are a shoitha ble effect of the atmo- 

fpheri¢ 


of the Atmofpbhere. 113 


fpheric tides produced by heat, as the gentle wind obferved 
at the times of high water in the ocean, even during wea- 

ther in othef refpects calm, proceeds from an atmofpheric 
tide produced by attraétion. 

The difficulty of breathing which people experience in the 
torrid zone, under an atmolpheric tide, arifing from heat, 

mutt be afcribed as much to a rarefaction of the air thereby 
occafioned, as to the heat itfelf. A like effect, in regard to 
breathing, is perceived on high mountains; which however 
arifes from the thinnefs of the air on thefe eminences, for 
here the heat can haye no part in the rarefaétion. 

It happens fometimes, in warm countries, that during the 
atmofpheric tides, the heat and rarefaction of the air increafe 
to fuch a degree that they create fcorching and fuffocating 
winds, known under the name of Sc/anos ;, the violence of 
which proceeds fo far fometimes, that they deftroy on the 

‘fpot thofe who are immediately expofed to them. Abun- 
dant and horrid inftances of this circumftance are quoted by 
the Abbé Richard in his Natural Hiftory of the Air and 
Meteors which have occurred in the Defarts of Arabia, in 
e neighbourhood of the Perfian Gulph, and other places. 
Befides thefe /olanos, it is obferved alfo, fometimes, that 
“the wind fuddenly ruthes from all quarters to that point 
where the air is moft rarefied, which occafions ftorms and 
urricanes in that part by the mutual fhock of the air and 
the vapours ftreaming in all directions towards one centre, 
“and the winds then blow backwards again from this point to 
‘every quarter of the heavens till the equilibrium is reftored. 
This effe&t, fo natural and common, has long aftonifhed thofe 
who never employed themfelves in endeavouring to difcover 
the caufe. 
In the laft place, there is good reafon for conjecturing that 
‘the fame phyfical caufes which produce the different atmo- 
‘fpheric tides, with their confequences, contribute alfo to . 
‘thange the weather and temperature, and to produce at the 
fame time a great many other meteorological phenomena. 


‘ 


VoL. V. Q Il. On 


Por fe 


II. On, the Nature and est BO of the Sun and F. ‘edd 
Stars. By Witttam Herscue., LL.D. F.R.S.* 


Aone the celeftial bodies, the Sun is certainly the 
firt which fhould attra& our notice. It is a fountain of © 
lizht that illuminates the world! It is the caufe of that — 
heat which maintains the productive power of Nature, and 
makes the earth a fit habitation for man! It is the central 
body of the planetary fyfiem; and what renders a know-_ 
ledge of it {till more interetiing to us is, that the numberlefs 
ftars which compofe the univerfe, appear, by the ftriéteft ana- — 
logy, to be fimilar bodies. Their innate light is fo intenfe, 
that it reaches the eve of the obferver from the remoteft re- 
gions of {pace, and forcibly claims his notice. 

Now, if we are convinced that an enquiry into the nature 
and properties of the fun is highly worthy of our notice, we 
may alfo, with great fatisfaction, reflect on the confiderable 
-progrefs that has already been made in our knowledge of this 
eminent body. Tt would require a Jong detail to enumerate 
all the various difcoveries which have been made on this 
fubjeét; I fhali therefore content myfelf with giving only. 
the moft capital of them. 

Sir Tfaac Newton has thewn that the fun, by its attractive: 
power, retains the planets of our fyftem im their orbits: he 
has alfo pointed out the method whereby the quantities of 
matter which it contains may be aceurately determined. Dr. 
Bradley has afliyvned the velocity of the felar light with a 
“degree of precilion exceeding our utmoft expectation, Gal- 
lileo, Scheiner, Hevelius, Caffini and others have afcertained 
ithe rotation of the fun upon its axis, and determined the po- 
fition of its equator. By means of the tranfit of Venus over 
«the difk of the fun, our mathematicians have caleulated it 
ediftance frem the earth; its real diameter and magnitude 
the denfity of the matter of which it is compofed; ‘and th 
fall of heavy bodies on its furface. 


* From the Pailofophical Tranfadlions of the Royal Society for 179 
Part [. 


Bite aa 


On the Sun and Fixed Stars. T15 


| From the particulars here enumerated it is fuffiiciently ob- 
‘vious, that we have already a very clear idea of the vaft tm- 
| portance and powerful influence of the fun on its planetary 
_fyftem : : and if we add to this the beneficent eects we feel 
on this globe from the diffufion of the folar rays; and con- 
“fider that, by well-traced analoyies, the fame effects have 
e been proved, to take place on other planets of thisfyitem, 
& er, {hould not wonder if we were induced to think that no- 
thing remained to be added in order to complete our know- 
ledge: and yet it will not be dificult to fhew that we are 
fill very ignorant, at leaft with regard to the internal con- 
' ftruction of the fun. The various “conjectures which have 
‘been formed on this fubje&, are evident marks of the un- 
' certainty under which we have hitherto laboured. 
The dark {pots in the fun, for inftance, have been fuppofed 
to be folid bodies revolving very near its furface. They have 
been conjectured to be the fmoke of volcanoes, or the feam 
f floating upon an ocean of fluid matter. They have alfo been 
taken for clouds. They were explained to be opaque maffes 
fwimming on the fluid matter of the fun, dipping down 
occafionally.- It has been fuppofed that a fiery liquid fur- 
rounded the fun, and that, by its ebbing and flowing, the 
higheft parts of it were occafionally uncovered, and appeared 
under the fhape of dark {pots; and that, by the return of the 
| fiery liquid, they were @gain covered, and in that manner 
{ cceffively affumed different phafes. The fun itfelf has been 
bf salled a globe of fire, thongh perhaps metaphorically. The 
wafte it would undergo by a gradual confumption, on the 
fuppofition of its being ignited, has been ingeniou(ly calcu- 
lated: and, in the Faose point of view, its immenfe power of 
eating the bodies of fuch comets as draw very near to it 
has been affigned. 
The bright fpots, or faculee, have been called clouds of 
t, and alee vapours. The light of the fun itfelf has 
been fuppofed to be directly invifible, and not to be perceived 
unlefs by reflection; though the proofs which are brought 
n fupport of that opinion feem to me to. amount to no more 
than, what is fufliciently evident, that we cannot fee when 
all of light do not enter the eye, 
Q2 But 


116 On the Nature and Conftrudtion 


But it is time to profit by the many valuable obfervations ; 
we are now in poffeffion of. A lift of fucceflive eminent 
aftranomers may he named, from Gallileo down to the pré- ~ 
fent time, wlio have furnifhed us with materials for exa- — 
mination. 

In fi upporting the ideas I fhall propofe in this paper, with 
revard to the phyfical conftruction of the fun, I have availed — 
myfelf of the labours of all thefe aftronomers, but have been | 
induced thereto only by my own actual obfervation of the — 
folar phenomena; which, befides verifying thofe particulars — 
that had been already obferved, gave me fuch views of the 
folar regions as led to the foundation of a very rational fy{- 
tem. For, having the advantage of former obfervations, my 
lateft reviews of the body of the fun were immediately di- 
rected to the moft effential points ; and the work was by this 
means facilitated, and contracted into a pretty narrow com. — 

afs. 

The following is a fhort extraét of my obfervations on the 
fun, to which I have joined the confequences I now believe | 
myfelf entitled to draw from them. When all the reafonings” 
on the feveral phenomena are put together, and a few addi-, 
tional arguments taken from analogy, which I fhall alfo add, 
are properly confidered, it will be found that a general con- 
clufion may be made which feems to throw a “coufiderablem 
light on our prefent fubject, 7 

In the year 1779 dere was a fpot on the fun which was 
larce enough to be feen with the naked eye: By a view of 
it with a feven feet reflector, charged with a very high power, 
it appeared to be divided into two parts. The largeft of the” 
two, on the 19th of April, meafured 1'8”,06 in diameter 5 
which is equal in length to more than 31 thoufand miles, 
Both together muft certainly have extended above 50 thou 
fand. . 

The idea of its being occafioned by a volcanic explofic o 
violently driving away a fiery fluid, which on its return would 
gradually fill up the vacancy, and thus reftore the fun, in that 
place, to its former {plendour, | ought to be rejected on many — 
accounts. To mention only one, the great extent of the a | 


of the Sun and Fixed Stars. ry 


lefs violent and Jefs pernicious caufe may be affigned to, ac~ 
count for all the appearances of the {pot. When we fee a 
dark belt near the equator of the planct Jupiter, we do not 
recur to earthquakes and volcanoes for its origin. An atmo- 
iphere, with its natural changes, will explain fuch belts. Gur 
fpot on the fun may be accounted for on the fame principles, 
The earth is furrounded by an atmofphere compoled of va~ 
rious elaftic fluids. The fun alfo has its atmofphere; and if 
dome of the fluids which enter into its compofition fhould 
‘be of a fhining brilliancy, in the manner that will be ex- 
plained hereafter, while others. are merely tranfparent, any 
temporary caufe which may remeve the lucid fluid will per- 
mit us to fee the body of the fun through the tranfparent 
ones. - If an obferver were placed on the moon, he would 
_fee the folid body of the earth only in thofe places where the 
tranfparent fluids of our atmofphere would permit him. In 
others, the opaque vapours would reflect the light of the fun 
without permitting his view to penetrate to the furface of 
our globe. He would probably alfo find that our planet had 
occafionally fome fhining fluids in its atmofphere; as, not 
unlikely, fome of our northern lights might not efcape his 
notice, if they happened in the unenlightened part of the 
earth, and were feen by him in his long dark night. Nay, 
we have pretty good reafon to believe, that probably all the 
planets emit light in fome degree ; for the illumination which 
femains on the moon in a total eclipfe cannot be entirely 
afcribed to the light which may reach it by the refraCtion of 
the earth’s atmofphere. For inftance, in the eclipfe of the 
moon Oétober 22, 1790, the rays of the fun refracted by the 
atmofphere of the earth towards the moon, admitting the 
mean horizontal refraction to be 30 50’7,8, would meet in a 
focus 189 thoufand miles beyond the moon; fo that confe- 
quently there could be no illumination from rays refracted 
by our atmofphere. It is, however, not improbable, that — 
about the polar regions of the earth there may be refraétion 
enough to bring fome of the folar rays to a fhorter focus. 
The difiance of the moon at the time of the eclipfe would 
require a refraction of 54’ 6”, equal to its horizontal parallax 
at 


118 ; On the Nature and Conflruétion 


at that time, to bring them to a focus fo as to throw light 
op the moon. 

The unenlightened part of the planet Venus has alfo been- 
feen by different perfons, and not having a fatellite, thofe 
regions that are turned from the fun cannot poffibly thine by 
a borrowed light; fo that this faint illumination muft denote 
fome phofphoric quality of the atmofphere of Venus. 

In the inftance of our large fpot on the fin, I conclude 
from appearances that I viewed the real body of the fun 
itfelf, of which we rarely fee more than its thining atmo-~ 
fphere. 

In the year 1783 I obferved a fine large fpot, and followed 
it up to the edge of the fun’s limb. Here I took notice that 
the fpot was plainly depreffed below the furface of the fun; 
and that. it had very broad fhelving fides. I alfo fufpected 
fome part, at leaft, of the fhelving fides to be elevated above 
the furface of the fun ; and obferved that, contrary to what 
ufually happens, the margin of that fide of the fpot which 
was fartheft from the limb was the broadeft. ‘ 

The luminous fhelving fide of a fpot may be explained by 
a gentle and gradual removal of the {hining fluid, which per- 
mits us to fee the globe of the fun. As. to the uncommon 
appearance of the broadeft margin being on that fide. of the 
fpot which was fartheft from the limb when the {pot came 
near the edge of it, we may furmife that the fun has inequa~ 
lities on its furface, which may poffibly be the caufe of it, 
For, when mountainous countries are expofed, if it fhould 
chance that the higheft partof the landfeape are fituated fo as 
to be near that fide of the margin, or penumbra of the fpot, 
which is towards the limb, it may partly intercept our view of 
it when the fpot is feen very obliquely. This would require 
elevations at leaft five or fix hundred milés high; but confider- 
ing the great attraction exerted by the fun upon bodies at its 
furface, and the flow revolution it has upon its axis, we may 
readily admit imequalities to that amount. From the centri- 
fugal force at the fun’s equator, and the weight of bodies at 
its furface, I compute that the power of throwing down a 
mountain by the exertion of the former, balanced by the_ 

fuperior 


of the Sun and Fixed Stars. 119 
fuperior force of keeping it in its place of the latter, is near 
6+ times lefs on the fun than on our equatorial regions; and 
as an elevation fimilar to one of three miles on the earth 
would not be lefs than 334 miles on the fun, there can be 
no doubt but that a mountain much higher would ftand 
very firmly. The little denfity cf the folar body feems alfo 
to be in favour of the height of its mountains; for, ceteris 
paribus, denfe bodies will fooner come to their level than rare 
ones. The difference in the vanithing of the thelving fide, 
inftead of explaining it by mountains, may alfo, and perhaps | 
more fatisfactorily, be accounted for from the real difference of 
the extent, the arrangement, the height, and the intenfity of 
the fhining fluid, added to the occafional changes that may 
happen in thefe particulars during the time in which the fpot 
approaches to the edge of the difk. However, by admitting 
large mountains on the face of the fun, we hall account for 
the different opinions of two eminent aftronomers; one of 
whom believed the fpots depreffed below the fun, while the 
other believed them elevated above it. For it is not impof~ 
fible that fome of the folar mountams may be high enough 
occafionally to project above the fhining elaftic fluid, when, 
by fome agitation, or other caufe, it is not of the ufual 
height: and this opinion is much ftrengthened by the re- 
turn of fome remarkable {pots which erved Caffini to afcer- 


’ tain the period of the fun’s rotation. A very high country, 


or chain of mountains, may oftener become vifible, by the 
removal of the obftructing fluid, than the lower regions, on 
account of its not being fo deeply covered with it. 

In the year 1791 I examined a large fpot on the fun, and 
found it evidently deprefied below the level of the furface ; 
about the dark part was a broad margin, Yr plane, of confi- 
derable extent, lefs bright than the fun, and alfo lower than 
its furface. This plane feemed to rife, with fhelving fides, 


up to the place where it joined the level of the furface. 


In confirmation of thefe appearances, I carefully remarked 
that the difk of the fan was vifibly convex: and the reafon of 
my attention to this particular, was my being already long 
acquainted with a certain optical deception, tinat takes place 
now and then when we view the moon; which i is, that all 

the 


326: On the Natur? and Conftru€hon 


the elevated fpots on its furface will feem to be cavities, and 
all cavities will aflume the fhape of mountains. But then, 
at the fame time, the moon, inftead of having the convex ap= 


pearance of a globe, will feem to be a large concave portion , 


of an hollow fphere, As foon as, by the force of imagination, 
you drive away the fallacious appearance of a concave moon, 
you. reftore the mountains to their protuberance, and fink 
the cavities again below the level of the furface. Now, when 
JI faw the fot. lower than the fhining matter of the fun, and 

an extended plane, alfo deprefled, welch fhelving fides rifing 
up to the level, I alfo found that the fun was convex, and 
appeared in its natural globular ftate. Hence I conclude 
that there could be no deception in thofe appearances, 

How very ill would this obfervation agree with the ideas 
of folid bodies bobbing up and down in a fiery liquid? with 
the fmoke of volcanoes, or feum updn an ocean? And how 
eafily it is explained upon our foregoing theory. The re- 
moval of the fhining atmofphere, which permits us to fee 
the fun, muft naturally be attended with a gradual diminu- 
tion on its borders: an inftance of a fimilar kind we have 
daily before us, when through the opening of a cloud we fee 
the fky, which generally is attended by a furrounding hazi- 
nefs of fome fhort extent; and feldom tranfits, from a perfect 
clearnefs, at once to the greateft obfcurity. 

Aug. 26, 1792. I examined the fun with feveral powers, 
from go to 500. It appears evidently that the black fpots 
are the opaque ground, or.body of the fun; and that the 
luminous part is an atmofphere, which, being interrupted or 
broken, gives us a tranfient glimpfe of the fun itfelf. My 
»-feet reflector, which is in high perfection, reprefents the 
fpots, as it always ufed to do, much depreffed below the fur- 
face of the luminous part. 

Sept. 2, 1792. I faw two fpots in the fun with the 
naked eye. In the telefcope I found they were clufters of 
fpots, with many fcattered ones befides. * Every one of them 
was certainly below the furface of the luminous difk. 

Sept. 8, 1792. Having made a {mall fpeculum, merely 
brought to a perfect figure upon hones without polifh, I 
found that,*by ftifling a great part of the folar rays, my ol- 

9 ject- 


of the Sun and Fixed Stars. rak 


jeét-fpeculum would bear a greater aperture; and thus en- 
abled me to fee with more comfort, and lefs danger. The 
furface of the fun was unequal; many parts of it being ele- 
vated, and others depreffed. This is here to be underftood 
of the fhining furface only, as the real body of the fun can 
probably be feldom feen otherwife than in its black fpots. 

It may not be impoffibie, as light is a tramfparcnt fluid, 
that the fun’s real furface alfo may now and then be per- 
ceived ; as we fee the fhape of the wick of a candle through 


its flame, or the contents of a furnace in the midit of the 
brightett glare of it: but this, I fhould fuppofe, will only 
‘happen where the lucid matter of the fun is not very accu- 


mulated, 

Sept. 9 93 1792. T found one of the dark {pots in the fun 
drawn pretty near the preceding edge. In its neighbourhood 
I faw a great number of elevated bright places, making va- 
rious figures: I fhail call them facule with Hevelius; but 
without affigning to this term any othet meaning than al 


it will hereafter appear ought to be given to it. I fee thefe 
faculz extended, on the preceding fide, over about 1-6th 


part of the fun; but fo far from refembling torches, they 
appear to me like the fhrivelled elevations upon a dried ap- 


ple, extended in length, and moft of them are joined toge~ 


ther, making waves, or waviig lines. 
By fome good views in the afternoon, I find that the ref& 
of the furface of the fun dees not contain any facule, excep: 


_ afew on the following, and equatorial part of the fun. To- 
_ wards the nerth and fouth I fee no facule: there is all over 


¢ 


the fun a great unevennefs in the furface, which has the ap- 
eee of a mixture of fmall points of an unequal licht ; 
but they are evidently an unevennefs or roughnefs of high 


and low parts. - 


_ Sept. 11, 1792. The facule, in the preceding part of the 


: fun, are much gone out of the difk, and thofe in the follow- 


jng are come on. A dari fpot alfo is come on with them, 
Sept. 13, 1792. There are a great number of facule on 

the equatorial part of the fun, towards the preceding and 

"following parts. I cannot fee any towards the poles; buta 

' toughnels is vifible every where. . 

r Vou, V. R Sept. 16, 


142 On the Nature and Conffrudiion 


Sepé. 16, 1794. The fun contains many large facule on 

the following fide of its equator, and alfo feveral on the pre-= _ 
ceding fide. I perceive none about the poles. They feem 
gencrally to accompany the fpots; and probably, as the fa- 
cule certainly are elevations, a great number of them may 
occafion neighbouring depreffions, that is to fay, dark fpots. 
+ The facula being dtevuaond! very fatisfactorily explains thé 
reafon why they difappear towards ‘the tniddle of the fun, and | 
re-appear on the other margin; for, about the place where 
we lofe them, they beein to be edge-ways to our view ; and 
iF between the facule thould lie dic fpots, they win! moft 
frequently break out in the middle of the fon, becaufe they 
are no longer covered by the fide-views of thefe facule. 

Sep. 22,1792. There are not many facule in the fun, 

and but few {pots ; the whole difk, however, is very much 
stieed with roughnels, like an orange. Some of the lowett 
parts of the inequalites are blackith. 

Sept. 23,1792. The following fide of the fun contains 
many facule near the limb. They take up an arch of about 
50 degrees. There are likewife fome on the preceding fide, 
The worth and fouth is rough as ufual, but differently dif- 
poled. The faeula are ridges of elevations above the vee 
furface. 7 i 4 

Feb. 23, 1794. Fy an experiment I have juft now tried, 
i find it confirmed that the fun cannot be fo diftinétly viewed 
with a fmall aperture and faint darkening elaffes, as with a 
Jarge aperture and {ttonger ones ; “hp jatar is the method F 
ae ays ule. 

One of the black fpots on the preceding margin, which 
was greatly below the furface of the fun, bad, next to it, a 
protuberant lunip of fhining matter, a little bn¢hter than the 
reft of the fun, 

About all the fpots, the fhining matter feems dota meca 
difturbed ; and is uneyen, lumpy, and zig-zagged in an it- 
regular manner. 

[call the fpots black, not that they are entirely fo, but 
merely to diftinoulfh them; for there is not one of them 
to-day, which is not partly, or entirely, covered over with. 
whitith and unequally bright nebulofity, or cloudinefs, This, 

‘ak in 


of the Sun and Fixed Stars. 123 


in many of them, comes near to an extinétion. of the ae 

and in others, {eems to bring on a iubdivifion, 

Sept. 28, 1794. There is a dark {pot in the fun on. the 
following fide. It is certainly depreffed below the fhining 
atmofphere, arid has fhelving fides of {hining matter, which 

' rife up higher than the general furface, and are brighteft at 
the top. “The preceding fhelving fide is rendered almott in- 
vifible by the overhanging of the preceding elevations, while 
the following is very well expofed ; the fpot being apparently 

_ fuch in figure as denotes a circular form viewed in an oblique 

- direction, 

~ Near the following margin are many bright elevations, 

clofe to vifible deprefiions. The depreiied parts are lets 
bright than the common furface. 

The penumbra, as it is called, about this fpot, is a confi- 
derable plane, of lefs brightnefs than the common furtace, 
and feems to be as much deprefled below that furface as the 
{pot is below the plane. 

Hence, if the brightnefs of the fun is occafioned by the 
lucid atmofphere, the intenfity of the brightnefs muft be lefs 
where it is depreffed ; for light, being bait alt be 
_ the more intenfe the more it is deep. 

- O88. 12,1794. The whole furfaee of the fun is diverfified 

by shisquality in the elevation of the fhining atmofphere. The 
loweft parts are every where darkefi; and every little pit has 
_ the appearance of a more or lefs dark {pot. 
_ + A dark fpot, which is on th< preceding fide, is furrounded 
by very great inequalities in the elevation of the lucid atmo-» 
 fphere; and its depreffion below the fame is bounded by an 
_ immediate rifing of very bright light. > 

O08. 13,1794. The fpot in the fun Lobferved yefterday 

is drawn fo near the margin, that the elevated fide of the fol- 

_ lowing part of it hides all the black ground, and ftill leaves 
_ the cavity vifible, forthat the ceprefiion ‘of the black {pots, 
guid the elevation of the facule, are cqually evident. . 


* 


Y 
*. 


[To be continued. j 


> 


R2 ‘ WI. On 


é [: 32g 


HIE. On the Prodwtion of Caft Irox, and the Operations of tha q 
Blaft-Furnace. By Mr. Davip MusuHet, of the Clyde 
Tron-Waorks. Communicated by the Author. 


L was my wifh, in the papers preceding this communica-+ 
tion, to convey a clear and competent idea of the nature of © 
iron as a metal; as alfo of ores, and iron-ftones in general. 
~ T have endeavoured to explain, upon principles grounded on 
experiment, the chief agents of change in the fmelting ope- 
ration, fo far as they affect the quality of the materials pre- 
‘ pared. J have aimed at perfpicuity rather than minutenefs, 
which often becomes tedious; and renee: the facts may 
not. be conveyed in a ftyle fo popular as communications, 
which profefs a conveyance of praétical truths, generally are, 
yet, I truft, this wall form no real bar to their utility. When 
facts are to be learned, and principles fatisfaétorily explained, 
it is furely beft to begin by the examination of fimple caufes; 
and tracing their agency according to their quantities, rela- 
tive proportions, and affinities. Thefe faéts. will undonbt~ 
edly, in the end, be more radically underftood by ufing fuck 
_ phrafes, er figns, 2s denote i each a refpective quality af. _ 
fixed in confequence of a knowledge of its properties and ef-s 
fects. In fhort, if the language ot reafoning of our manu~ 
factories is ever to become fcientific ; if philofophy and che- 
tuaitry are ever to become of general utility in the perfection 
ef any branch; then thofe truths which conftitute the foun< 
gation of all feience are not to be rejected, though clothed — 
ina drefs which at firft fight appears difcordant to our ha. 
bits, or burdenfome to our memory. 

_ The operations I am about to defcribe have never as yet 
received any explanation confonant to true philofophy or — 
chemical facts ; yet there are few which prefent a more beau- 
, tiful chain of affinities, decompofition, and recombination, 
than the manufacture of dron in all its various ftages. An 
extenfive foundry is a laboratory fraught with phenomena of — 
the moft interefting nature in chemiftry and natural philo= 
fophy : are we not then juftly furprifed to find that prejudice 
‘ Rub 


On the Produétion of Caft Iron, &e. 325 


ftill reigns there; and that the curious manipulations of thefé 
regions are ftill fhrouded with error and mifconception 5 as 
if Saher dingy ftruéture forbade the entrance of genius, or 
configned her laborious unlettered fons to an endlefs ftretch 
of pacha obfeurity ? 

The plate of the blaft-furnace, given in the preceding 
Number, having a full defcription appropriated to it, I fhall 
proceed to detail the train of preparation neceflary before the 
furnace is brought to produce good melting iron. 

The furnace belting finifhed, the bottom “ail fides of it, iw 
two feet up the {quare funnel, receive a lining of common — 
bricks upon edge, to prevent the ftone from fhivering or 
mouldering when the fire comes in contaét with it. On the 
front of the furnace is ereéted a temporary fire-place, about 
four feet long, into the bottom of which are laid correfpond- 
ing bars. The fide-walls are made fo high as to reach the 
under-furface of the tymp-ftone ; excepting a {mall fpace, 
which afterwards receives an iron plate of 1! inches thick- 
nefs, by way of a cover: this alfo preferves the tymp-ftone 

_from any injury it might fuftain by being in contaé with the 
flame. A fire is now kindled upon the bars, and is fed occa- 
fionally with {mall coals. As the whole cavity of the furnace 
ferves as a chimney for this fire, the draught in confequence 

is violent, and the body of heat carried up is very confider- 
able. In the courfe of three weeks the furnace will thus 
become entirely free from damp, and fit for the reception of 
the materials: when this is’ judged proper the fire-place is 
removed, but the interior bricks are allowed to remain till 
the operation of blowing commences. Some loofe fuel is 
then thrown upon the bottom of the furnace, and a few baf- 
kets of cokes are introduced; thefe are allowed to become 
thoroughly ignited before more are added. In this manner 
the furnace is gradually filled; fometimes entirely full, and 
at other times 5-8ths or 3-4ths full. The number of baf- 

Kets full depend entirely upon the fize of the furnace: that 

in the plate will contain goo bafkets. If the coal is fplin 
the weight of each bafket-full will be nearly 110lb.x 

_ g00=99,000lb. cokes. As this quality of cokes is made 

with a lols of nearly 50 per cent, the original weight in raw 
4 coals 


/ 


726 Ci« - On the Production of Caft, Iron, Y 


coals will be equal to 198,000 lb. When we refleét that thts 
vaft body of ignited matter is replaced every third day, when 
the furnace is properly at work, a notion may be formed ,of 
the immenfe quantity of materials requifite, as alfo the con- 
fequent induftry exerted to fupply « one or more furnaces for 
the fpace of one year. 

When the furnace is fuficiently heated. throughout, {pe- 
cific quantities of cokes, iron-{tone, and blaft- furnace cinders 
‘are added: thefe are called charges. The cokes are com- 
monly filed in bafkets, which, at all the various iron-works, 
are nearly of a fize. The weight of.a bafket, however, de- 
pends entirely upon the nature and quality of the coal, being 
from 70 to 1121b. each *.. The iron-ftone is filled into boxes, 
which, when moderately heaped, contain 561b. of torrefied 
iron-ftone; they often exceed this when the ftone has been 
feverely roafted. The firft charges which a furnace receives, 
contain but a fmall proportion of iron-{tone to the weight of 
cokes: this is afterwards increafed to a fuli burden, which is 
commonly 4 bafkets cokes, 3201b.; 2 boxes iron-ftone, 112 ]b.; 
i box blaft-furnace cinders, 60 or 7olb.t. At new works, 
where thefe cinders cannot be obtained, a {imilar graphy 
of limeftone is ufed, 

The defcent of the charge, or burden, is facilitated by open-. 
ip the furnace below two or three times a-day, throwing 
out the cold cinders, and admitting, for an hour at a time, 
a body of frefh air. This operation is repeated till the ap- 
proach of the iron-ftone and cinder, which is always an- 
nounced by a partial fufion, and the dropping of lava through. 
the iron bars, introduced to fupport the incumbent materials” 
while thofe on the bottom are carried away. The filling. 
above is regularly continued, and when the furnace at the 


* This fame variety in te coal renders it almoft impoffible, under one’ * 
defcription, to give a jult idea of the proportions ufed at various blaft-.” 
furnaces: to avoid being too diffufe, I fhall confine my defeription con-. 
ne€ted with a coal of a medium quality, or a mixture of fplint and free~ - 
coal, a bafket of which will weigh from 78 1b. to 84lb. 

+ A preference at firft is always given to blaft-furnace cinders in place 
of lime; being already vitrified, ‘they are of much eafier fufion, and tend to’ 

; pater. the furface of the hearth by glazing it over with a black vitrid 


chat. j 
top. 


Se, See 


and the Operations of the Blaft-Furnace. 129 


top has acquired a confiderable degree of heat, it is then 
judged time to introduce the blaft; the preparations neceflary 
for which are the following :— 

The dam-ftone is Jaid in its place firmly imbedded in fire- 
gay; the dam-plate is again “imbedded on this with the fame 
cement, and is fubject to the fame inclination. On the top 
of this plate is a flight depreffion, of a curved form, towards 
that fide fartheft diftant from the blaft, for the purpofe of 
concentrating the feoria, and allowing it to flow off in a con- 
nected ftream, as it tends to furmount the level of the dam. 
From this notch to the level of the floor a declivity of brick- 
work is.erected, down which the fcoria of the furnace flows 
in large quantities. The opening betwixt the dam and fide- 
walls of the furnace, called the fauld, is then built up with 
fand, the loofe bricks are removed, and the furnace bottom 
is covered with powdered lime or charcoal-duft. The ig- 
nited cokes are now allowed to fall down, and are brought 
forward with iron bars nearly to a level with the dam. The 
{pace between the furface of the cokes and the bottom of the 
tymp-plate is next rammed hard with {trong binding fand 3 
and thefé cokes, which are expofed on the outfide, are co- 
vered with coke-duft.  Thefe precautions being taken, the ° 
tuyere-hole is then opened and lined with a foft mixture of 


fire-clay and Joam: the blaft is commonly introduced into 


the furnace at firft with a finall difcharging-pipe, which is 
afterwards increafed as occafion may require. In two hours 


after blowing, a confiderable quantity of Java‘will be accu- 


mulated; iron bars are then introduced, and perforations 
made in the compreffed matter at the bottom of the furnaces: 
the lava is admitted to all parts of the hearth, and {oon tho- 
roughly heats and glazes the furfaces of the fire-ftone. Shortly 


after this it rifes to a level with the notch in the dam-plate, 


and by its own accumulation, together with the forcible ac- 


tion of the blaft, it fows over. Its colour is at firft black ; ‘its 
fraéture denfe, and very ponderous; the form it affumes in 
funning off is flat and branched, fometimes in long ftreams, 


and at other times lefs extenfive. If the preparation has been 
; well conduéted, the colour of the cinder will foon change to 


White; and-the metal, which in the {tate of an oxyde formerly 
i coloured 


/ 


128 On the Produétion of Ca/? Tron, 


coloured it, will be left in a difengaged ftate in the furnacés 
When the metal has rifen nearly to a level with the dam, it 
is then let out by cutting away the hardetted loam of the 
fauld, and conveyed by a channel, made in fand, to its pro- 
per deftination ; the principal channel, or runner, is called 
the ow, the lateral moulds are called the pigs. 

In fix days after the commencement of blowing, the fur- 
nace ought to have wrought berfelf clear, and have acquired 
capacity fufficient to contain from 5000 to 7000 weight of 
iron. The quality ought alfo to be richly carbonated, fo as 
to be of value and eftimation in the pig-market. At this 
period, with a quality of coal as formerly mentioned, the 
charge will have increafed to the following proportions :— 
§ bafkets cokes, goolb.; 6 boxes iron-flone, 336]b.; 1 box. 
-limeftone, roolb. 

An analyfis of the {melting operation, and the tendency 
which the individual agents have to produce change in the 
quality and quantity of the iron, come next under confidera-~ 
tion. Let us, however, firft notice the characteriftic features 
exhibited by the different kinds of iron while in fufien, 
whereby the quality of the metal may be juftly defined. 

When fine (No. 1.) or fupercarbonated crude iron is run 
from the furnace, the ftream of metal, as it iffucs from the 
fauld, throws off an infinite number of. brilliant fparkles of 
carbon. ‘The furface is covered with a fluid pellicle of car 
buret of iron, which, as it flows, rears itfelf up in the moft 
delicate folds: at firft the fluid metal appears like a denfe, 
ponderous ftream, but, as the collateral moulds become 
filled, it exhibits a general rapid motion from the furface of 
the pigs to the centre of many points; millions of the fineft 
undulations move upon each mould, difplaying the greateft 
nicety and rapidity of movement,. conjoined with an uncom~ 
monly beautiful variegation of colour, which language is in 
adequate jufily to defcribe. Such metal, in quantity, will 
remain fluid for twenty minutes after it is run from the fur~ 
nace, and when cold will have its furface covered with the 
beautiful carburet of iron, already mentioned, of an uncom- 
monly rich and brilliant appearance. When the furface of 
the metal is not carbureted, it is {mooth like forged iron, and — 

always 


F 


J 


and ihe O;erations of the Blaft-Furnace. 12g 


always convex. In this ftate iron is too tich for melting 
without the addition of coarfe metal, and is unfit to be uifed 
in a cupola furnace for making fine caftings, where thinnefs 
and a good {kin are requifite. 

No. 4, or oxygenated crude iron, when iffuing from the 
blaft-furnace, throws off from all parts of the fluid furface a 
vaft number of metallic fparks: they arife from a different 
eaufe than that exerted in the former inftance. The extreme 
privation of carbon renders the metal fubject to the combina- 
tion-of oxygen fo foon as it comes into contac with atmo- 
fpheric air. This truth is evidently manifefied by the ejec- 
tion of fmail fpherules of iron from all parts of the furface: 
the deflagration does not, however, take place till the globule 
has been thrown two or three feet up in the air; it then in- 
flames and feparates, with a flight hiffing explofion, into a 
great many minute particles oF brilliant fire. When thefe 
are collected they prove to be a true oxyde of iron, but fo 
much faturated with oxygen as to poffefs no magnetic obe-= * 
dience. The furface of oxygenated iron, when running, is 
covered with waving flakes of an obfcure fmoky fine: ac- 
companied with a hiffing noife; forming a wonderful con- 
traft with the fine rich covering of plumbago in the other 
ftate of the metal, occafionally parting and exhibiting the 
iron in a flate of the greateit apparent purity, agitated in 
numberlefs minute fibres, from the abundance of the carbon 
united with the metal, 

When iron thus highly oxygenated comes to reft, {mall 
fpecks of oxyde begin to appear floating upon the furface: 
thefe increafe in fize; and when the metal has become folid, 
the upper furface is found entirely covered with a feale of 


blue oxyde of various thickneffes, dependent upon the ftage 


of oxygenation or extreme privation of carbon. This oxyde, 
in common, contains*about 15 per cent. of oxygen, and is 
very obedient to the magnet. In place of a dark blue f{mooth 


furface, convex and richly carbonated, the metal will exhibit 


a deep, rough, concave face, which, when the oxyde is re+ 
‘moved, prefents a great number of deep pits. This iron in 
fufion ftands lefs convex than carbonated iron, merely be- 
caufe it is lefs fufceptible of a ftate of extreme divifion ; and 
_ Vou. VY, S indeed 


130 On the Produéction of Caft Iron, 


indeed it feems a principle in all metallic fluids, that they 
are convex in proportion to, the quantity of carbon with which 
thev are faturated. ‘This iron flows dead and ponderous, and 
rarely parts in fhades but at the diftance of fome inches from 
each other, 

This is a flight fketch of the appearance of the two ex- 
treme qualities of crude, or pig-iron, when in a ftate of fu- 
fion. According to the divifion formerly made, there ftill 
remains two intermediate ftages of quality to be deferibed : 
thefe are, carbonated and carbo-oxygenated iron; that is, 
No. 2 andg of the manufacturers. Carbonated iron exhi- 
bits, like No. 1, a beautiful appearance in the runner and 
pig. ‘The breakings of the fluid, in general, are lefs fine s 
the agitation lefs delicate ; though the em of the fluid is 
equal, if not beyond that of the other. When the internal 
ebullition of the metal is greate(t, the undulating fhades are 
fmalleft and moft numerous: fometimes they affume the 
fhape of {mall fegments; fometimes fibrated groups; and at 
other times minute circles, of a mellower colour than the 
eround of the fluid. The furface of this metal, expofed to 
external air, when cooling is generally flightly convex, and 
full of punétures: thefe, intron of a weak and fufible nature, 
are commonly finall in the diameter, and of no great depth. 
In firong metal, the punctures are much wider and deeper. 
This criterion, however, is not infallible, when pig-iron of 
different, works is taken collectively. At each individual 
work, however, that iron will be ftrongeft whofe honey- 
combs are largeft and deepett. 

Carbo-oxygenated, or No. 3, pig-iron, runs f{moothly, 
without any great degree of ebullition or difengagement of 
metallic {parks. The partings upon its furface are longer, 
and at greater diftances from each other than in the former 
varieties ; the fhape they affume is either elliptical, circular, 
or curved. In cooling, this metal acquires a confidezable por- 


tion of oxyde; the furface is neither markedly convex nor — 


concave; the punctures are lefs, and frequently vanifh alto- 


gether. Their ablence, however, is no token of a fmooth — 


face fueceeding: in qualities of crude iron oxygenated be- 
yond this, 1 have already mentioned that a concaye furface 


Ss 


aie oa 


—_— 


—_— ee ee 


—_— ee ee eee 


and the Operations of the Blaft-Furnace. ‘131 


is the confequence of the extreme abfence of carbon; and 
that, in proportion as this’principle is abfent, the furface of 
_ the iron acquires roughnefs and afperity. 

It may perhaps be proper here to mention, once for all: 
that although, for convenience, the manufacturer has, from 
a juft eftimation of the value of the metal in a fubfequent 
manufacture, afixed certain numbers for determinate quali- 
ties of iron, yet it is dificult to fay at what degree of fatu- 
‘ration of carbon each refpective term commences: fuffice 
it then to fay, that the two alterative principles, oxygen and 
earbon, form two diftinct clafles, that in which oxygen pre- 
dominates, and that in which carbon predominates ; the 
latter comprehends No. 1 and 2 of the manufacturers, the 
former includes oxygenated, white and mottled; and the 
equalifation of thefe mixtures form, as has already been no- 
ticed, the variety of carbo-oxygenated crude iron. 

I fhall now obferve fome things relative to the various 
faces whicly crude iron aflaumes. .No,1 and 2, with their 
intermediate qualities, poffefs furfaces more or ‘Jefs convex, 
and frequently with thin blifters: this we attribute to the. 
prefence of carbon, which being plentifully interfperfed bes 
‘twixt and throughout the particles of the metal, the ten- 
dency which the iron has to fhrink in cooling is entirely 
done away; it tends to diftend the aggregate of the mafs, 
_ and to give around face, by gradually elevating the central 
"parts oF: the furface, which are always lalt to lofe their flat 
__ idity. 
Again, that quality of iron known by the name of No. 3, 
or carbo-oxygenated, is mo{t commonly found with a flat 
furface. If we fiill farther trace the appearance of the fur- 
face of pig-iron, when run from the furnace, we {hall find 
No. 4, either with a white or mottled fracture, poflefied of 

concave faces rough end deeply pitted. Beyond this it may 

_ be imagined that every degree of further oxygenation would 
be productive of a furface deeper in the curve, and rougher, 
with additional afperities. The contrary is the cafe: when 
» crude iron is fo far debafed as to be run from the furnace in 
clotted Jumps highly oxygenated, the furface of the’ pigs is 
found to be more convex than that of No.1 iron 3) but then 
HedKi: a the 


1920+ On the Produfizon of Caft Iron,” 


the fracture of fuch metal prefents an impure mafs covered 
on both faces with a mixture of oxydated iron, of a blueifhk 

colour, nearly metallic. In fhort, this quality of iron is in-_ 
capable of receiving fuch a degree of fiuidity as to enable us 

to judge whether the convexity of its furface is peculiar to its 

ftate, or is owing to its want of divifion as a fluid, whereby 

the gradual confolidation of the metal is prevented. 

Thefe features fufficiently diftinguifh betwixt the various 
qualities of crude iron after they are obtained from the blaft- — 
furnace: there are, however, criterions not lefs infallible, 
whereby we can prejudge the quality of the metal many 
hours before it is run from the furnace. Thefe are the co- 
Jour and form of the fcoria, the colour of the vitrid cruft 
upon the working bars, and the quantity of carburet which 
is attached to it. The variety of colour and form in the cin- 
der almoft univerfally indicate the quality of the metal on 
the hearth. Hence, from a long courfe of experience, have 
arifen the following denominations: ‘‘ Cinder of fulphury 
iron ;”? “ Cinder of No. 1, No. 2, and No. 3;’’ and ‘ Cin- 
der of ballaft iron.” Although at different works, from local 
circumftances, the fame kind of fcoria may not indicate pre- 
cifely the fame quality of iran, yetthe difference is fo fmalk 
that the following defcription of the various cinders may 
convey a very juft idea of their general appearance. 

When the fcoria is of a whitifh colour and fhort form, - 
branching from the notch of the dam, and emitting from its 
fiream beautiful fparks of ignited carbon, refembling thofé 
ejected from a crucible of caft fteel in fufion, expofed to ex- — 
ternal air, or to the combuftion of fine fteel filings in a white ~ 
flame; if, when iffuing from the orifice of the furnace, it is — 
of the pureft white colour, poffeffing no tenacity, butin a — 
ftate of the greateft fluid divifion, and, when cold, refembles: 
a mafs of heavy torrefied fpar, void of the fmalleft vitridap- — 
pearance, hard and durable, it is then certain that the fur- — 
nace contains /ulibury iron, i. ¢. fuper-carbonated iron. At. 
blaft-furnaces, where a great quantity of air is thrown in pen _ 
minute, fuper-carbonated crude iron will be obtained with a 
cinder of a longer form, with a rough flinty fra€ture to- i 
wards the outfide of the column, . 


: That 
; 


{ 


and the Operations of the Blafl-Furnace. I 33 


That cinder which indicates the prefence of carbonated 
iron in the hearth of the furnace, forms itfelf into circular 
compact fireams, which become confolidated and inferted 
into each other; thefe are in length from three to nine feet. 
Their colour, when the iron approaches the firft quality, is a 
beautiful variegation of white and blue enamel, forming a 
wild profufion of the elements of every known figure; the 
blues are lighter or darker according to the quanuty of the 
metal and the aétion of the external air while cooling. When 
the quality of the pig-iron is fparingly carbonated, the blue 
colour is lefs vivid, Jefs delicate; and the externa] furface 
rougher, and more fullied with a mixture of colour. The 
fame feoria, when fufed in vefiels which are allowed to cool 
gradually, parts with all-its variety of light and fhade, and 
becomes of a yellowifh colour, fometimes nearly white when 
the quantity of incorporated metal has been {mall.. 

The cinder which is emitted from the bla{t-furnace when 
carbo-oxygenated (or No. 3,) iren is produced, affumes a 
long zig-zag form. The ftream is flightly convex in the 
middle; broad, flat, and obliquely furrowed towards the 
edges. The end of the ftreani frequently. rears itfelf into 
narrow tapered cones, to the height of fix or eight inches: 
thefe are generally hollow in the centre, and are eafily de- 
molifhed, owing to their exceflive brittlenefs. The colour 
of this lava is very various; for the moft part it is pale yel- 
low mixed with green, Its tenacity is fo great, that if, while 
fluid, a fmall iron hook is inferted into it at a certain degree 
of heat, and then drawn from it” with a quick but fteady 
‘motion, 20 to 30 yards of fine glafs thread may be formed 
with eafe. If the colours are vivid and variegated, the thread 
wil] poffefs, upon a minute feale, all the various tints of co- 
louring which is found in the columnar mafs. , When by 
accident a quantity of this lava runs back upon the difcharg~ 
ing-pipe, it is upon the return of the blafL impelled with fuch 
velocity as to be blown into minute delicate fibres, fmaller 
than the moft ductile wire; at firft they float upon the air 
like wool, and when at reft very much refemble that fub- 
flance. 

The prefence of oxygenated crude iron (Na. 4,) on the 

furnace~ 
A 


534 On the Produétion of Caft Iron, &e. 


farnace-hearth, is indicated by the Java refolving itfelf into 
long {treams, fometimes branched, .fometimes columnar, 
extending from the notch’ to the lowelt part of the declivity 5 
here it commonly forms large, flat, hollow cakes, or melines 
to form.conical figures: thefe are, however, feldony perfect; 
for the quantity of fluid Java, conveyed through the eentre of 
the column, accumulates fafter than the external fides of the 
cone are confolidated; and thus, when the ftructure is. only 
half finifhed, the fmall crater vomits forth its fuperabundant 
Java, and-is demolifhed. The current of fuch lava falls hea- 
vily from the dam as if furcharged with metal, and emits 
dark red fparks refembling the agitation of ftraw embers. 
Its colour is ftill more didien than the former defcriptions of 
fcoriz, and is found changing its hues through a g@reat va- 
riety of greens thaded with browns. iAivother’ variety of feo- 
ria, W hich indicates the fame quality of tron, affumes a fimi- 
jar form; but has a black ground colour mixed with browns, 
or is entirely black. When the latter colour prevails, the 
texture of the cinder becomies porous; the quantity of iron 
left is now very confiderable, and. fuch as will be eafily ex- 
tracted in the aff: av-furnace with proper fluxes. In cafes of 
total derangement i in the furnace, the fcoria will {till retain 
this black Gee: ur, although the quantity of metal may amount 


to 25 per cent.; the freeones however, becomes denfe, and ° 


its {pecific sai mereafes in proportion to the quantity of 
metal it holds incorporated. 

The next fource of information, as to the quality of the 
iron in the furnace, is to be got from the colour of the feoria 
upon the working bars, which are trom time to time inferted. 
to keep the furnace free from lumps, and to bring forward 
the feoria. When fuper-carbonated crude iron is in the 
hearth, the vitrid cruft upon the bars will be of a black co- 
lour and fmooth furface, fully covered with large and_ brik 
jiant plates of phambago. 

As the quality of the metal approaches to No. 2 (carbo- 
nated), the carburet upon the feoria decreafes both in point 
of quantity and fize. 

When carbo-oxygenated iron (No.3) is in the furnace, 
the ‘working hars are always coated’ witha lehter co- 


9 loured 


i 
| 
. 
: 


| 
| 
| 


A 


PEARS 


SLPS TTT ERS: 


ete 


> 


Hints for thé Formation of a Theory of the Earth. 135 


Youred fcoria than when the former varieties exift; a fpeck 
of plumbago is now only found here and there, vind that of 
the fmalleit fize. When the quality of the metal is oxy-, 
genated (No. 4.), not only have the plates of carburet dif- 
appeared, but alfo the coally colour on the external furface of - 
the feoria ; what now attaches to the bars, 1s nearly of the 
fame nature and colour as the lava emitted at-the notch of 
the dam. 

Thefe criterions are ‘fallible; for, 2 as the fufibility or car- 
bonation of the metal is enone in a direét ratio to the 
comparative quantity of the coally principle prefent in the 
furnace, fo in the fame proportion will the vitnid cruft 
encircling the working bars exhibit the prefence of that 
principle in the furnace. 


eee eee SSSSSSSSSSSSSSSSSSSSSSsSSsSSSSsSS9S99n9Snsns9998989nsns9sms er 


1V. Agenda, or a Colle&ion of Obfervations and Refearches 

fe) 3 > 

the Refults of which may ferve as the Foundation for a 
Theory of the Earth, By M. Du Saussure. 


{Continued from Page 29.] 
CH A Pa XSET. 


Errors to be avoided in Ob fer: vations refpeting Geology. 


; ee are fome errors into which people may readily 
fall when they have not had long experience in any given 
kind of obfervation, and againft which it is of importance to 
put beginners at leaft on their guard. . 
2. One may be readily deceived in regard to the relative 
diftances of remote objects. All the ftars and planets appear 
‘to be at an equal diftance from us. Distant mountains all 
appear to be in the fame plain. Thus thofe, which are fitu- 
ated very far behind the reft, feem, to form one body with 
them; fo that people believe they fee continued and uninter- 
rupted chains when there are really none, and) where the 
mountains, on the contrary, are infulated, 
The abfolute diftance of objects, even when not very re- 
mote, is equally difficult to be afcertained on high moun- 
: tains, 


. 


146 “ate Hints for the Formation of 


tains, where the tranfparency of the air, and the. abfetice of 
vapours, deftroy the aérial perfpective. I have oftem-ima- ; 
gined that I had only two or three hundred fteps to make in 
order to reach a fummit, the diftance of which from me was 
more than a leacue in a firaight line. 

3. There ate a oreat many errors in regard to ftrata. Their 
great thicknefs may make one believe “that there are none — 
where they really exift. In the like manner , if the vertical 
ftrata, or thofe only very much inclined,- prefent their planes” 
to the eye of the obferver, he will think he fees fhapelefs and 
indivifible matics; while, if their feétions were feen, their 
divifions would readily be diftinguithed. A mountain then 
muit be feen under afpects that interfect each other at right 
angles before we can pronounce that it is not divided by 
ftrata. : 

4. At other times accidental fiffures, but produced how- 
ever by a caufe which is common to them, exhibit the ap- 
pearance of ftrata when there are none; or when, if there 
are, their fituation is very different from that of thofe ftrata. 
It is the internal tifue of the flone only which in many cafes 
can determine whether the divifions obferved are the interftices 
between ftrata or mere fiflures; becaufe the ftrata are con- 
ftantly parallel to the internal Jamine, or fchiftous texture of 
the ftone. Cryftals, the Jamellated texture of which may 
fometimes be confounded with a fchiftous texture, may af- 
ford an ex¢eption to this rule, by prefenting lamine perpeh- 
dicular to the planes of the firata; but it is not difficult to 
diftinguith them. - ; 

5. One may alfo form an erroneous opinion refpecting a 
the direGtion of a mountain, or of its ftrata, when the eye is 4 
not fituated in their prolongation, or at leaft near it. 

6. The apparent fituation of the ftrata may alfo lead into 
an error. They appear horizontal even w hen they are very — 
much incliried,‘and when they are not feen but in a fection -— 
formed by a plane parallel to the common fection of their 
planes with the horizon. It is im poffible to judge of their — 
inclination, and to meafure it with certainty, but on’a fee~ 7 
‘tion perpendicular to the common fe¢tion, w hich I have jut t 
‘Miehttoned. 4 


ve 


a@ Theory of the Earth. 139 

6. A. The greateft error, however, is that which mdy 
‘be committed in regard to the fuper-pofition of firata. I 
have often feen novices in the ftudy of mountains believe 
that one ftratum repofed on another; one of granite, for ex- 


| ample, on one of flate; becaufe they found flate at the bot- 


tom of the mountain, anid granite at the top; while the flate 


was only laid againft the bafe of the mountain, and the granite, 
‘on the other hava: was funk in the earth far below the flate. 
We muft not thei! fay, that a ftratum is fituated below ari- 


other, but when we really fee it extending itfelf below it. 


7. And even when we diftin&ly fee a rock placed above 


another, we muft examine whether that which is uppermoft 


does not occupy that fituation accidentally ; whether it has 
not flipped, or rolled down, from a more elevated mountain ; 


‘and, in the laft place, though they may be clofely connetted, 


one muft examine whether their prefent fituation is really 


al Sen! 


. 


‘the fame in which they were formed, arid whether they have 
‘not been reverfed, and united accidentally in a fituation con- 
trary to that of their original formation. 


8. One is frequently deceived, alfo, in regard to the nature 
of ftones and of mountains. Though:a well-accuftomed eye 


may often judge at fome, and even a confiderable diftance, of 

the kind of ftone of which a mountain is compofed, fuch ° 
_ judgment is however often erroneotis: mountains of granite, . 
or gneifs, tender and deftruétible, often affume, at a diftance, 


the round form of fecondary mountains; fometimes, alfe, 


‘mountains of calcareous flone, hard of their kind, ‘and iii 


- fata either vertical or very much inclined, prefent the bold 


forms, the peaks, and fharp-angled indentations of the gra- 
nite fummits. 

g. People are often deceived even on a hear view. A ftone 
may have a foreign covering of mica, for example, while the 
interior part is of a very different nature. 

to. Effervefcence with the nitrous acid is commonly con- 
fidered as a certain character of calcareous ftone; but this 
charaéter may be deteptive, fince barytes and sided a ef- 
fervefce alfo*: and we muft not confider it enough to touch 

* And, on the other hand, there are calcareous ftones which do nét 


‘CFfervefee, j 
Vor. V, Lc a ftone 


a8 Hints for the Formation, of 
a fione with the nitrous.acid, or to Jet fall a.drop of the acid 
(on its furface,. finee the abforbing earth, whateyer it is, may 
Ae only difleminated between, argillaceous or filiceons partie 
cles,» We, mutt, therefore: immerfe),a fragment. of the, fione 
in, a quantity of the acid fuficient todidiolge. it entirely, fi it 
he wholly foluble, and, eblerve wheter there saesiid any — 
Fefiduum that withflands folution, fg ty 7 vtite tiv 
11. Fhe action of the air andiof, meteors often, ne foflils 
appearances abfolutely diferent from thofe which ‘they shad 
_ before they were fubjected torit.,, Wemutt not then be fatif-- 
fied with a fuperficial examination; .¢ mult, found the rocks 
to the quick where the ngsion of meteoric aap has Not per’ 
netrated. - f 
12. People are et seer aoa pare paeneonnd 
ftones as fimple {tones, when the compofition of them, does nat 
manifelt itfelf on the firkt ¥ iew, either on account of the {mall- 
peut of their compofing parts, or becaufe fome of thefe parts ~ 
are cach inclofed feparately in.a eoyering which conceals,the 
interior of them. One may guard;againft this error by.ob- 
Fomving the foil in the fun with ftrong magnifying glaffes, — 
after having moiftened ats furface with water or the, nitrous 
acid, and fill better by expoling it oxadually to the flame of 
the blow-pipe. A + 4 
13. People are often. deceived an regard, to ery Aallifation, 
either im the true form.of the oryfials, or, above all, in.taking ~ 
for real. cryftals\parafite cryitals, or fuch as have hace formed 
in the moulds made\by eryfials of another kind. . Thus,we - 
dee \cryftals of quartz,’ petro-filex, and jafper, formed, in the 
morvlis made by caleareous, eryfials, and which have, affumed 3 
the form of the latter. ul aries 
14, In. régard to, errors, o¢cafioned by ignorance jof the 
ditingive éharasters of foflils, and.of, the:names proper for 
them, the only means of avoiding fuch, errors is toftudy with - 
care goad authors 3 aud, above all, collections formed, or at” 
leaft atrangediand. titled, by,ablemineralogifts. . a 
15. But when ethe, Aightet dowbt,is entertained in “regard 
to the denomination which ought, tobe give en to any fofiil, 
_an exact defeription muf he made either of its external cha- 
raéters or its moti ftriking phyfical properties, fuch as weight 


‘ i Q and 


\ Bel Thesry of the Earthy 73g 

3 and folubility *. | “If this defeription is well’ drawn up, the 
érror. refpeting the name may be rectified, and the obfervas 
~ tion will not be loft, a$ it ‘would be were there any reafon to 
 fiifpeét the juftnels of the’denomination, and no means of cér- 
reGting i it by a defeription f. ’ 

* 16. When the characters of a foflil give it facha hkenefs 
to another that it is found near the limits which'{e sparate the 
_ Senera or fpecies of thefe' two foffils, we' mutt follow’ the ex- 
_ ample of Werner and his difciples}:by marking: that this fof- 
- filis intermediary, or forms a tranfition from the one fpecies 
| to the other. For if we fhould afcrile™it- exclutively-to the 

enus A, without noting the characters which bri ring it.near 
to the genus B, another obferver, on feeing the Bins fofil, 
“might refer it to the genus B, and no one koala Kiiow which 
of them was déccived. 
-, 17- People are often deceived alfo by mixing opinion with 
obfervation, and giving the former for the latter ; as when 
- people affert, that they have feen veftiges of extinguifhed vol- 
canoes, » Dbecautle: they have feen black or porous. ftones, or 
§ ‘ftones of a prifmatic form, without deigning to deferibe t them 

ge care, but by qualifying them. merely as lava‘ or ale 
. 186 In the laft place, a very frequent fouree of e1 error o 
ereat a confidence ‘in the fi fidelity of one’s memory or in oe 
; julinefs of one’s firft obfervations. Thee two ii of con- 
fidence go often hand in hand; and people éannot BR? ard 
-againft the errors, which are the confequence of them, but 
“by noting down, on-the fpot, :all: obfervations to witch jany 
‘importance is attached, cfpecially if they are a\litthe complex, 
and carry away fpecimens, with ‘their characters earefitll+ 
“marked upon them, of the objects that ‘are the fubject of 


a ‘Hardnefs, refrangibilitv, eleétricity, &ce HH. ; 

gsSaul A perfon now dead, who in h’s time was confidered as a unlidgis 
_ it, } Wrote ‘to me that he had found marine fhells in'pranites Iebegged 
jim to give mevan exa€t defeription of: the fione which he calledspraniie, 
He ait fo; but E perceived that the {tone was a free- ftone ov fand-ftonéyand 
7 € fpecinens he wfterwards fent me proved that [was not deceived. 7 Wie 

ix 4y here recollect Reeupero’s pyrites of Altna.) The errors of thiskind, 
rifing from falfe denominations, are innumerable ;: foranexaét know- 
UA a of inineral fubhiahces is more difficult to be obtained, and more raré,, 
7 an is generally nnagined;—Note of the Auruomy: (41 4 | 


a i Te thefe 


140 Objervations on Animal Eleétricity. 


thefe obfervations; for it is not fpecimens of rare objects 
merely that fhould be collected. The end, indeed, of the 
geological obferver is, not to form a cabinet of curiofities, 
but he muft carry away fragments af things apparently the 
moft common, when an exaét determination of their nature 
may be interefting to theory. People may thus employ, with 
advantage, the means of confirming or reétifying their firft 
obfervations, and of making profound refearches and compa- 
rifons impoffible to be made on the fpot *, 
[To be continued. | 


SS eee 
——————————————e——eEeEESSSSeSSSeSSCaQaaoaoaoaoaoee eee 


Y. Obferuations on Animal EleGricity, and particularly that 
called Spontaneous. By J.J. HEMMER. 


[Concluded from Page 7. ] 


ig a letter, dated Jane 21, 1787, which I received from 
M. De Sauffure, he confeffes that he had not made any far- 
ther experiments on animal cle¢tricity; and that he did not 
know whether any had been made by others. As I was 
convinced, however, that a complete knowledge of that elec- 
tricity which is produced in the human body by the friétion, 
of the clothes, as well as fpontaneoufly, might be of great 


* We think i¢ our duty to fubjoin here fome advice to travellers in 
regard to the quettions which they may afk in the different towns. 

Whence do they procpre the materials proper for building; fuch as — 
lime, platter, tiles, flate, ftones of different kinds, and fand ? Dothey — 
burn turf or coal; and where are they found? Where do they procure 
their porter’s clay, fuller’s earth, the clay ufed for refining fugar, their 
whetftones and millftones? To obferve with what the ftreets are paved ; 
of what ftone the fteps of ftairs are formed; marks for boundaries, &c.; 
and to earn from what place they are brought. To afcertain oobieeitde y 
wells or the foundation of houfes are dug; and whether there are in the 
neighbourhood any rayjnes or prectpices. Thefe queftions will ferve to | 
facilitate the means of obferving the nature of the ground, by pointing 
eut the natyral or artificial excavations that may exift in the neighbour- 
hood, or which cught to be vifited. For the fame reafon it is properta — 
examine the fhores of rivers, It will be of ufe alfo to take a general view 
ef the country from the tops of towers and of the higheft fteeples. It will 
be of fome importance alfo to enquire, in the country, whether the isha-~ 
bitants make ufe of lime, marl, plafter, coal, earth, or turf-afhes, for ma- 
puriog their land; ang from what places thefe fubftances are procured. C, 


j utility 


Obfervations on Animal Eleétricity. 141 


utility both to the fcience of electricity in general, and par- 
ticularly to medical electricity, I refolved to make refearches 
on this fubjeét by means of experiments. The method I 
employed was as follows :—In order that I might examine 
the electricity of my own body, I infulated myfelf on a board 
which ftood on glafs feet. I then touched, for a determined 
time, (at firft commonly half a minute, afterwards only a 
moment,) the plate of my condenfer, which I have defcribed 
in another place*; I then applied the condenfer to a Caval- 
Jo’s highly fenfible electrometer, as -improved by M. De 
Sauffure, and, by means of a glafs tube rubbed with a piece 
of woollen cloth, examined the kind of electricity when an- 
nounced by the diverging threads. The eleétricity of the 
plate of the condenfer or ele¢trometer, which correfponded 
with that of the body, I marked with + when pofitive, with 
— when negative, and with o when none was prefent. J 
made my experiments on the 21ft of February 1786; and 
fince that period have repeated them, not only on myfelf, but 
on other perfons, both male and female, of various ages and 
different conftitutions, when they were in motion, or at reft; 
dreffed and undreffed; when tired, and in good fpirits; hot or 
cold; fafting or full; fleeping or awake; at different tempe~ 


atures of fs weather and of the apartment, &c. 


Refults of the ‘Ehperiments? 


1. Animal electricity is common to all men; Bead get 
found it, in the courfe of my experiments, on thirty perfons 
of both fexes and all ages, and of every habit of body, I can 
with juftice conclude on its being general. 

2. Animal electricity is different in different men, at the 
fame place and at the fame time}; not only in ftrength, but 


-alfo in the kind; being in many weak, and others ftrong; in 


fome pofitive, and in fome negative. 

3. This difference of electricity is often obferved in: dif- 
ferent perfons, when, befides time and place, the other cir- 
gumfances appear to be all equal. 

4. The &rength and kind of this eleéricity are often dif. 


* See Gren’s Fournal der Phyfik, Vol, IL Part I1. p. 210. 
ferent; 


T42 Obfervations on Animal Eleéricity. 
ferent; not only in different men, but alfo in the fame pers 
fon. In 2422 experiments, in which I examined my own ~ 
electricity, E found it 1252 times pofitive, 771 times nega- 
tive, and 399 times o. The electricity of my maid, in 94 
experiments, was, on the other hand, 19 times ee 33 
times Negative, and 42 times o. 

5, It often happens, tifat, during the experiment, the eee 
tricity changes; that is, from pofitive to negative, or from 
ftronger pofitive to weaker, and at laft becomes o. It 'then 
pafies from the Jaft to weak negative, and gradually to 
ftronger. 

6, [t happens alfo, not unfrequently, that the eleétricity, 
at the commencement of the experiment, is ftrongly pofitive 
_ or negative, but paffes afterwards to the oppofite kind with 

the like force, which continues for a confiderable time. 

7. Notwithflanding this wonderful and almoft contmaal 

alternation, animal elestricity appears to be naturally pofi- 

tive. As the eleGtric matter is diffufed throughout all na- 

‘ture, and adheres, in a fixed form, to no body, all the arti- 
cles of our nourifhment contain each their fhare of it. The 

electric fluid is difengaged, and diffufed with the blood and 
juices through the body; from which it is conveyed off, after - 
being accuniulated in it, by the pores of the fkin and other 
duéts, when there is.no interruption in them. This is con- 
firmed by experience; for when animal eleétricity is exa- 
mined in a body expofed to no violent exertions, as when a 
perfon fits or repofes, ‘and when there is confequently no great 
lofs of heat, it is commonly pofitive. Thus the eleGtricity of 
my body, which I ethane while fitting at reft, when the 
natural heat of the body was not dif ‘urbed, appeared, im 332 

experiments pofitive, in 14 negative, and in 10 was o. 

8. When animal ele&iricity, therefore, is 0, or negative, 
the body muft. be in an unnatural {tate (ala violento). . 
g. Cold changes natural or pofitive animal electricity into 
the oppofite kind, or at Ieaft leffens it. In 60 experiments 
{ made on myfelf after coming from a cold air, the tempes — 
sature of which’ was-at the freezing point or below it, my | 
electricity was 38 times, negative, 7 times 0, and 15 times 
pohtive e, the laf. being not unfrequently weak, T had often 
an 


at 


‘Wa Obfervations on Animal Eleéirieity, 143 


_ & opportunity of obferving the -pleafant phenomenon, that 
_ the negative electricity atline from cold, after pulling off 2 
cold and putting on-a warm coat, was {peedily converted into 
pofitive, or the degrees next to it. When the thermometer 
5 dttood feyera] degrees above the freezing point, and a fome- 
what cold ara preyailed, the latter was s fificient to produce 
negative oro electricity, as I experienced , four, times. OF 
43 times, while I fat lightly clothed in a warm apartment, 
_ the electricity was 8 times 0, thrice— , and twice w eakly +. 
Nay, when I clothed myfelf well, and remained any time at 
a cooler part of the room, fuch as the open door or window, 
it found the electricity either negative or weakly pofitive, For 
producing this effect, it is in breneral fufficient if a part only 
of the warm body be expofed to cold. When the electricity 
was ‘commonly +, while [ fat at perfect reft, on my ufuat 
q chair, I oftentimes remarked that it was perceptibly nega- 
tive if my feet were extremely cold, without being baa to 
; aflign aay other caufe for, this phenomenon. It is, how-= 
ever, fully proved by the following circumftances; During 
23, times that I wafhed my hands. ra face with cold water, 
‘ the eleétricity was only 15 times perceptibly +, 8 times—, 
£ thrice 9, and 7 times weakly +; though a moment nes 
or after, it was, for the moft part, frongly si ser 
That cold impedes pofitive electricity, or makes it lefs and . 
seduces it to o, may be €afily- comprehended ; becaufe cold. 
© caufes every thing to contract, leflens the pores of animal 
Dodies, and, by thefe means, obftruéts the efcape of the clec- 
q tric matter. That it, however, conyerts this electricity into 
‘hegative, or gives to the external part of animal bodies the 
; ‘property of extraGing from other bodies, when in contaét 
; with eh a part of their natural reuse is not eal, to be 


fined a iG of their sais quantity. of electricity. , But 
hen, by the contraction of the pores, they receive no more 
of the eleétric matter from the interior parts of the body 
they muft, in order that the equilibrium be kept up, not fru 
tain n any Jofs of it. This lofs,is either real or apparent, The 
former can {carcely he, affewted, as there are not fufficient 
grounds for fugh an.idea. Yor if it be faid that the electric 
ba oe 4+ : matter 


r44 Obfervations oh Animal Eleéricity. 


matter naturally contained in the external part of the body, 
is expelled by that accumulated more and more in the interior 
parts, on account of the cold, and which thereby acquires a 
ftronger repulfive power, it is of no weight; fince this power 
would prevent the plate of the condenfer from giving up any of 
its natural electricity to the finger when applied to it. There 
is more reafon, therefore, to affert the latter, viz. that this 
want is only apparent; that is, that the eleétric fluid, which 
the external parts of the body naturally poffefs, is not expelled 
by the effects of cold, but fixed, or fo faft united with the 
parts in which it is contained, that it Iofes all movement, 

and gives no indications of its prefence, This kind of union 
is not uncommon in nature: it takes place in regard to the 
particles of fire, which produce heat; when moift bodies 
evaporate, or when falt is mixed with ice. 

10. Laflitude impedes alfo the pofitive animal eleétricity, or 
changes it into the oppofite. During 16 times that I walked 
backwards and forwards in my apartment, or was otherwife 
employed, the temperature of the weather being 10, 12, 14, 
and more degrees of heat, and no cold wind prevailing at 
the time, I foimid the eleétricity only once weakly +, five 
times o, and ten times—. In 32 experiments, when ftand- 
ing at reft, the electrisity was 30 times 0, and twice weakly +. 
In 27 experiments, while I fat at reft, it was always ftrong- 
ly +3 and in five experiments, while walking at a moderate 
pace, it was perceptibly +. I found the cafe to be the fame 
on my fervant and another young man. 

I will not, however, fay that the electricity, when the body 
is in a ftate of reft, always ceafes, or is changed from pofitive. 
Many times the ftrength of the body is greater than to allow 
of its being exhaulted by fatigue, as I have more than once 
experienced. 

11. By rubbing a part of the body, pofitive cle&tricity is 
not impeded. T he rubbing may be performed with linen 
or woollen. 

12. Sudden, fpeedy, and violent ‘motion can change every 
kind of animal eleétricity into the oppofite. A luminous and 
beautiful appearance was occafioned when I inclined and 
‘taifed my body fuddenly in turns, and threw upwards quickly 


and 


Obfervations on Animal Eleétricity. 145 


and with a certain degree of violence, fometimes my.arms, 

and fometimes my feas: Under thefe circumftances the 

electricity was thrice changed from — to +, and 16 times 
from 0, or weak +, to—. On my fervant, under the eas 

circumftances, it was eight times changed from + to — 

and on my maid five times fronr — to +. 

13. Everyother motion of the body, not connected with Roh, 

violence, or with uncommon agitation of the limbs, when it 

does not produce much fatigue, does not impede pofitive ani- 
- mal electricity. 
14. Such motion is no impediment alfo to negative animal 
| electricity. ; 
_ 15. After noon, or dinner-time, animal electricity is not 

_ greater thah common. 

8 16. The ufe of coftee makes no change in animal electricity, 
17. Continual {training of the thoughts is not only favour- 
( able to pofitive animal eleCtricity, but increafes it in an un- 
- common degree. 
_ 18. Animal electricity is impeded by perfpiration. 
_ ‘Ig. Animal eleétricity is {tronger in winter than in fummer, 
20. Repofe at noon, or any other fhort fleep when fitting in 

’ the day-time, does not difturb pofitive animal electricity. 

; 21. The breath does not conduct animal electricity in a 
mee pele manner, I breathed on the cover of the condenfer 
in various places, but I never found the leaf traces of elec- 
‘tricity. The eleétricity, in all probability, was difperfed too 
‘fpeedily, or was too fubtile to be perceptible. 

22. Bodily motion is by no means neceffary for seagate 
animal eleétricity; 
23. Neither does it depend on the movement occafioned 

by refpiration. 

24. Animal electricity arifes alfo without frifion of the 
elothes, My experiments leave no doubt on this fubject; as 
T found the electricity on my own body lively and durable for 

half an hour, or an hour, when I had on no clothes. Ido 
not fay, however, that the friction of the clothes does not 
jnereafe it. 

» 25. Animal eleétricity is excited without any friGtion of the 
external parts of the body. 
26. There is alfo a {pontaneous kind of animal electricity, 
By OL. V. oo U VI. Obn 


gh tt 


— 


seat 


[ 146 J 


YI. Obfervations on Pot-afh; being an Inquiry how far the — 
mifchievous Effeéts of Septic Acid are reftrained by Pot-afh — 
and other Alkalies, particularly in refpeét to the Effedis — 
of Septite of Pot-a/b (Nitre or Saltpetre) upon Animal 
Flefh intended to be eaten, and upon the Human Stomach; 
in a Letter from Dr. Mitchill to Dr. Priefiley, dated ~ 
Plandomz, May 4, 1799; Communicated by Dr, M1tT~ © 
CHILL, 


Ox a former occafion (2 Medical Repofitory, p. 236 ef 
__feq.) an attempt was made to fhew that the /epéic acid, which ~ 
‘is formed in certain putrefactive procefles, was materially dif- 
ferent in its conftitution and qualities from the xitrous acid 
obtained by diftillation from faltpetre. Since the compofi- 
tion of that piece, I have obferved that Juncker, in his view | 
of the doétrines of Beccher and Stahl], (2 Confpeétus Chimie, 
p. 280,) is of the fame opinion, declaring, that in whatever 
manner the work of feparating it from the putrefcent or 
other bodies with which it was naturally mingled, was un- © 
dertaken, ‘ ne micula tamen acidi nitrof pure fiftitur,” zo¢ 
@ particle of pure nitrous acid can be obtained. And he warns 
his reader, that in the cbfervations which he offers he means ° 
that /pirit of nitre ONLY which is liberated from its connec- © 
tion with an alkaline falt. On the native feptic acid, which ~ 
is, as he allows, furnifhed fo largely by the animal kingdom, 
(p. 277,) and js by far the moft active and interefting form 
of oxygenated fepton, Juncker, like mott other writers, hag 
faid {carcely any thing at all. 

The highly deftrijctive effets of this offspring of putreface — 
tion have been pointed out in detail in a former eflay (t Me- © 
ical Repofitory, p. 39, 40), in which it was obferved that 
certain fubftances, and among others pot-afh in particular, 
poffeffed a power to reftrain and curb its ferocity. The neu-- 
tral falt, formed by the union of this peftilential acid with — 
the fixed alkali, is the faltpetre or nitre of the ihops and of 
commerce. Concerning the medicinal and economical qua- 
jities of this fubftance, it: is manifeft to me that there are — 
many miftakes yet prevalent : : and they appear | to be worthy 
pf being pointed out and corregted, Ts 

ng 


Dr. Mitchill’s Obfervations én Pot-Afb. 147 

The feptite of pot-ath has been denominated a falt of many 
excellent qualities, a fal polychrefius; and a great phyficiant 
once wiflied, for the good of his profeffion, there could be 
found ove other temedy fo certain and fteady in curing dif- 
| eafes as nitre. It has likewife been termed an antiphlogi/lic 
| femedy, good for all manner of inflammatory difeafes with 
 phlogiftic denfity of the blood; poffefling fine attenuating 
| powers, being in nowife acrimonious; and happily calcu- 
’ lated to withftand a putrefcent flate of the body. It has fur- 
| ther been calied a refrigerant, a diuretic, and a carminatives 


Such are fome of the fuperlative effects afcribed to this 
ni compound of the acid of peftilence and pot-afh: and for 4 
| tonfiderable time after I became acquainted with the mif- 
 thievous effects, wrought occafionally by the naked feptic 


' therefore did not appear to me improbable that the charac- 
| ter of the compound of the two might, as in a multitude of 
other cafes, be exceedingly different from that of either the 
» conftrtuent acid or alkali. 

But latterly I have been inclined to the opinion, that pot- 
, afh is capable of combination with oxygenated feptom in dif- 
_ ferent degrees ; that is to fay, fepton, before combining with 
the alkali, may have been united to more or /e/s of oxygen 3 
[fe and alfo fepton, im any of its degrees of oxygenation, may 
| be united with pot-afh in different proportions: in other 
words, the acid may vary in its /trengtb, ‘and likewife, ort 
pe every degree of firength, may be united to the alkali zn va- 
| rious proportion: The nitrum nitratum, defcribed by the older 
a chemifts, ig arr example of pot-ath _/uper-faturated with nitric 
acid, and, ftrange to tell! has beem extolled for its adyan- 
fageous operation in ardent fevers, accompanied with thirft 
and with a dry and foul tongue. I have ftrong reafon to 
~ think that there is a difproportion between the acid and al- 
f li in other forms of nitre; as I have known litmyus-paper 
_ to be turned repeatedly reddith by a watery folution of falt- 
os petre, the refidue of a quantity which was fwallowed by 
os, U2 miftake, 


7 


¢ 


148 © Dr. Mitchill’s Ob/ervations on Pot-Afh, 


miftake, and which nearly deprived a man of his life. Afet q 
of correct experiments is wanting to clucidate more com- : 
pletely this part of a very curious ‘and highly important fub- — 
ject. 
Be thefe things as they may, all experience fhews that the 
connexion between feptic acid and pot-afh is eafy to diffolve 5 
at leaft, a portion of oxy oo feparates very readily from the 
hitre. The experiment of reddening blood by mixing ‘pow- 
dered fat rtpetre with it, was known to Hoffman, and, I think, 
fairly evinces a partial decompofition of the falt. It feems to 
have a fimilar operation upon the refidue of that fluid in the 
flefh of flaughtered animals, and the reddening of the Jean © 
and fibrous part of meat is rit a owing fo the oxygen — 
attracted from the nitre. ; 
But a heightening of colour is not the only effect which — 
feptite of pot-afh works upon provifions fprinkled with it. ~ 
There are in many meats, efpecially of old animals, and of j 
thofe which have been a long time falted, a foughne/s and — 
bardnefs which render them difficult to be cut and to be — 
chewed. The feptic acid feems in fome degree to be dif- 
joined from the pot-afh, and evidently affifts in decompofing, — 
to a certain point, fhe vafcular and fibrous ftru€ture of the’ 
meat, The quantity of nitre generally put on is fmall; was 
the proportion ‘larget, the meat would be yet further difvad q 
ganifed, and be feared more /hort and tender, almoft even 
to rottenne/s. But the injurious effect of the nitre is pre=_ 
vented by the fea-falt commonly mingled with it, in the — 
manner and upon the principle defcribed in my “ Obferva-_ 
tions on Soda.” (2 Medical Repofitory, p. 292, et /eq.) The 
ufe of faltpetre, then, in curing provifions, 1s to make thenr 
reddifh and tender, and not to exercife an antifeptic and bard=~ 
ening power, as the muriate of foda does, r 
/With all thefe confiderations before me, I entertained” 
great doubts of the truth of thofe fine things told over and” 


‘mildnefs and wholefomenefs of nitre, and of its wonderful — 
effe&ts as a calmer and foother of difeafes. It feemed very | 
range to me, that the ua which before its union via 


i ee 
ees 


in a Letter to Dr. Pricftley: #49 
transformed, as, notwithftanding the laxity of their cohefion, 
to cure fuch difeates immediately afterwards. 

While I was confidering hele things, a cafe fell under my 
obfervation, which.allowed me fully to witnefs the operation 
of this boafted cooler, carminative, and febrifuge. It fhews, 
beyond a doubt, that feptic acid, though coerced by pot-afh, 
is in fome degree feptic acid fill Its native virulence does 
not even ee wholly forfake if. Nitre ought to be ranked 
among the poifons; for, in a fufficient dofe, it is truly a poi- 
fon. Though it may be adminiftered in {mall quantities with 
out exciting terrible fymptoms, it refembles in that refpect 
meft other venomous fubftances, which can be fwallewed 
without detriment, and even often with advantage, when 
their dofe is not too Jarge. It is time for writers of Difpen- 
fatories, and on Materia Medica, to know the facts concern- 
ing nitre and its operation, and to publifh them for the fake 
of undeceiving their readers. Too long has the medical 
world heen the dupe of idle and partial opinions on this fub- 
ject. Bead the following accident, and judge of what I have 
faid from the fymptoms induced by {wallowing feptite of pot- 
ath or faltpetre :-— 

A carman, of middle age, had followed his bufinefs as 
ufual on Saturday the 20th day of April 1799. On Sunday 
morning he determined to take a faline cathartic for an in- 
difpofition too trifling to require the advice of a phyfician. 
Accordingly his wife diffolved an ounce of what fhe believed 
to be fulphate of foda (Glauber’s falt) in water, and gave it 
to him at a draught. He fwallowed it. Soon after he was 


-feverely incommoded by what he termed “ a great weaknefs 


about his heart.’” Naufea came on, and was followed by 
vomiting of the contents of the ftomach, mixed with confi- 


: -derable quantities of blood at each time. His ftrength was 


exceedingly impaired: and a fenfation of coldnefs over the 
whole body was remarked by him, particularly in the extre- 


-mities. I did not fee him until after the bloody vomiting 


had continued at times for feveral hours, and then his pulfes 


“at the wrift were very flow. He was however quite rational, 
- and faid he then felt much better than he had done. On ex- 


amining what kind of falt he had take n, for fome cryftals of 


it remained in a wide-mouthed bottle, I found it to be fep- 


tite 


4%0 Dr. Mitchill’s Obfervations on Pot-Afh, i 

tite of pot-ath (faltpetre.) This was about cleven o'clock: 
before noon, and he had taken it at fix in the morning. As 
it had had no purgative effect, I ordered him fome cate oily 
and almond milk fweetened with fugar, or fome pe thle 
ee fome water-gruel. 

35 Commentar, de Rebus, &c. p. 196, a cafe is men- 
cand of death from taking an ounce of nitre: arid if a part 
of the quantity which this mam took had not been vomited 
tip, he probably would have died too. | The ol. ricini purged 
him gently, and he gradually got better, but complained 
very much of weaknefs about the preecordia. 

There are numerous other accidents not materially unlike 
thefe. Such occurrences give us no very favourable account 
of the benignity of nitre as a medicine. It is a pity that 
practifers of phyfic do not better underftand the component 
parts of their preferiptions. How few know that, in admi- 
niftering nttre, their patients are made to fwallow a portion 
of the naufeating and fickening acid of putrefaction ! 

Poffibly thefe yemarks may have a tendency to rempove the 
doubt-contained in your letter of April 11, 1799. You will 
hereby perceive that my native acid of fepton is a combination 
of this bafis with oxygen and water ; whereas your arézficial 


acid of nitre undergoes a partial davonsiedn by the heat of 


dittillation, and is adulterated befides with whatever happens 
to be mingled with it during and after its combination with 
the vegetable fixed alkali. And both thefe forms of acid 
differ from atmofpherical air; inafmuch as the former are 
chemical mixtures, the latter is mechanical. 

It would be better for fcience if the word ‘* nitre’” was re- 
jected altogether from ufe. Nzéria, whence the term comes; 
was, you know, a diftriét of ancient Egypt, famous for the 
quantity of mineral alkali which it afforded. (D’Anyille’s 
Geograph.—Egypt.) This faline fubftance has thence been 


called by the ames mitrum, mitre, &c. En confirmation of 


which, I obferve, in the Dictionary of Calepinus, printed at 
Bafil in 1538, that what they ealled mztrwm was a material 
employed to cleanfe clothes, and wath the bodies which wore 
them. And S. Bochart remarks, (1 Opera. Chanan, L. II. 
cap. xiv.) that the ancients made a kind of ley from a/besy 


Joday 


e 


in a Letter to Dr. Prieftley. Ist 


foda, and bole, (cinere, nitro, et cimolid,) for more effeCtually 
clearing their bodies from naftinefs when they bathed., I 
need not remark to you, that I employ the word ‘¢ nitre,”” 
Not in its ancient, but modern fenfe, 

It is highly defirabie that fome of our men, whofe opinions 
have weight with the public, would perufe the work of Lan- 
cifi, phyfician to Pope Clement XI, on the noxious exhala- 
tions of marfhes. (De Nox. Palud. Efflaviis.) By the per- 
fevering and luminous refearches of this great man, it was 
found, as long ago as the year 1716, that marfh-water, by 
fimple diftillation, (Jd7d. Lib. II. c. xii.) manifeited an acid 
quality ; and that calcareous {tones (Ibid. Lib. If. ¢.1i.) were 
better for paving the ftreets of cities than /liceous ones, be- 
caufe the alkaline nature of the former was adapted to imbibe 
the noxious moifture of the air, and fweeten the acid falts 
with which it abounded. Indeed, much of the matter des 
tailed by the writers.of our days on local fources of dif- 
tempers, may be found better obferved, and better ftated, by 
Lancifi, than in their writings. By the by I obferve he 
mentions the Englith philofopher Mayow, (Jdid. Lib. I, 
P. ii. cap. 2.) 

If the philofopher of Rome had reafoned upon his own 


' difcovery, he could not have failed to draw the inference, 
that by alkaline. fubffances might the HyDRA of peftilence 
_ be overcome.—As I have mentioned this moniter, I fhal] 


paufe a little to give you my opinion of the allegory among 
the ancients concerning her: and I attempt the explanation 
the more willingly, as I believe Lord Verulam has faid no- 
thing about it. The fable is this :—In Peloponnefus, between 


_Mycenz and Argos, there was a fen or marth of fome extent 


galled Lerna. This muddy and ffagnating pool was inhabited 


by Hydra, a horrible and devouring moniter with feveral 
heads ; fomé {ay feven, others nine, and others fifty. The 
gaalignity of her poifan was fugh that 2 wound from an ar+ 


Yow dipped into it was inftantly mortal. She made dreadful 


t 


; 
9 

a 
- 


. 


, 


havoc among the people of the furrounding country, and dez 
youred a great number of their fheep and other cattle. In 
obedience to the orders of the tyrant Euryfiheus, Hercules 
went to fight this deftructive and formidable creature. On 


hig 


s 


m53 Dr. Mitchill’s Obfervations on Pot-Afh, 


his approach, a crab came forth to the affiftance of Hydra: 

but Hercules crufhed the crab, and afterwards flew Hydra. 
Of the heads of Hydra, it’ was reported, when ome was cut 

off, two would fprout from the wound, unlefs prevented by 

the immediate application of fire. Hercules, availing himfelf 

of the aid of fire, fucceeded in his undertaking. In the ninth _ 
figure of Montfaucon’s 66th plate, there is a figure of Her- 

eulés with crabs near his feet, having, as the learned father 

eurioufly enough remarks, a relation to fome myftery which 

he does not comprehend. (1 Antiquity ee Art. Her- 

eules, chap. ix.) 

Now, it appears to me, this 1s an sffegsFy expels of the 
peftilential vapours emitted by the bog of Lerna, and of the 
means found by experience ufeful to “drain off its flagnant 
water, and to clear the adjoining and furrounding mor ites! 

The word “ hydra’’ is derived from idig, water. This 
fluid then, detained upon the marfh of Lerna, favoured oc- 
eafionally the production of unwholefome exhalations, Such 
vapours, being at once invifible and i injurious, were afcribed 
to fome preternatural enemy or deftruétive monfter; and 
being difiufed, or wafted around the country, and often- 
times cutting off both man and beaft, were fancied to be 
the effec of: the fuppcfed nionfter’s poifon. According to 
their extent and virulence was fhe reported to have fewer or 
more heads for preparing and inflicting this poifon. The 
mere draining off the water, and leaving the mud and flime 
bare, was termed ‘cutting off an head; and the imcreafe of 
deleterious gafes, m confequente of expofing fuch a naked 


furface, was aptly exprefled by the fprouting forth of two in 


its place. By cauterifing, or fearing, was underftood either 
the folar heat in drying the ground after the water was drained 
away, or the burning up of the trees, fhrubs, and obftacles 
to free ventilation by ordinary combuftion, or perhaps both. 
The crab, who was Hydra’s ally, perhaps does not refer to the 
fun’s place in the conftellation Cancer, fo much as to fhew the 
frequent recurrence of the difficulties, and the fuperior ftreneth 
and {kill requifite to overcome then:. In the whole allegory 
© Hercules’? may be underitood to mean “ infuperable con- 
rage and induftry.”” North America, at the elofe of the 18th 
7 century, 


‘well as “« hydra, 


in a Letter to Dr. Priefiley. 153 


century, wants a Hercules, This interpretation is confirmed 
by another confideration, that the ancients had not only 
their Hydra, who lived in the water, but their Cher/ydra, 


who remained afier the marth or fen was dried up. Cher- 


frdra, being derived’ from the two words, xpc0s, land not fit 
for the plough; and viex, the monfler of the fens; will thus 
mean the venomous and fickly condition of the neighbouring 
atmofphere after the water was exhaled, and the ground at 
the fame time not renderéd arable thereby, typified by a poi- 
fonous ferpent: and was thus expreffive of the rage of pefti- 
lential effuvia, which fometimes, and under certain circum- 
ftances, continue in a virulent a in dry weather, near 
their dried fources. 

Hydra is feemingly mentioned by Virgil (4En, vi. v. 576.) 
‘as 2 fictitious or poetical animal. Bathent, however, with his 
‘uiual prodigious erudition, appears defirous to make the whole 
ftory literally intelligible. (Hierozoici pars pofter. Lib. III. 
cap, xiti.)" But Lancifi, with a more clear and difcriminating 
mind, perceives that important phyfical truths are doricealal 
ander this two-fold allegory, and fhews how they are to be 
unriddled. (De Nox. Palud. Eff. Lib. IL. p. 1. cap. 3.)— 
Jn confidering thefe matters you will not fail to recolleé that 
the claffical writers, and others, ufe the word ‘ hydrus’’ as 
” and fome of them apparently confound 
the two. The former noun of the mafculine gender is pro- 
bably the name of the real animal, the water-/nake, the 
Jatter of the mnaginary one.—But of this enough. 

If peftilential matter, as I obferved before, can be fubdued’ 


by alkalies, then the formation of feptite of pot-afh in the 
‘alimentary canal mu(i be a very frequent and common pro- 
eefs. It is univerfally agreed that peftilential matter may be 
taken into the flomach by fwallowing; and no reafonable 


doubt can be entertained of its production within that organ, 


_and other parts of the intefiinal tube, from the corrupted re- 


mains of food. The whole tenor of prefcription, as explained 


_in my letter concerning the ufe of alkaline remedies in fevers, 
(1 Medical Repof. p. 265.) goes to fhew that the offending 
-eaufe is of an acid quality: and in its worft forms, I think 
_he acid engendered has fepton for its bafis; fince aliment, 


Vou. V. X containing 


154 Defeription of a Mercurial Gaxometer. 


containing this principle only, is capable of yielding that 
moft noxious compound. When feptic acid thus exifts in 
the alimentary canal, and carbonates, tartrites, &c. of pot- 
ath, are taken down, the ftronger acid is attraéted, and a 
proportional quantity of nitre or faltpetre is formed. Thus, 
in abundance of cafes, the praétifers who are fond of pre- 
feribing feptite of pot-afh might fpare themfelves the trouble, 
as. that faline compound is, in certain cafes, formed in the 
ftomach and bowels in confiderable quantity. What precife 
effect the nitre fo formed has on the inteftines, and on the 
conftitution at large, deferves to be inquired into with great 
care; for | am not without apprehenfion that fome of the 


fad fymptoms, occafionally attendant on fevers, are modified ~— 


by the feptite of pot-ath formed within the belly.—I believe, 
however, I muft now ftop, and trouble you no further for 
the prefent than by affuring you, that I hope much from 
-your aid in this inquiry, which you inform me you confider 
f€ as a happy train of difcovery ; 3” and that I am, very re- 


fpectfully, yours, 
SAM. L. MITCHILL, 
To Dr, Priefiley. 


VIL. Defcription of a Mercurial Gazometer conftrudted by 
Mr. W.H. Pepys jun. Communicated by the Author. 


if ME difficulty attending the exhibition of acid and al- 
kaline gafes, was the firft idlgeainent to. Prieftley, Lavoifier, 
and memees, to ufe mercury for fuch experiments; but the 


great expence and enormous weight of this fluid obliged 3 


many accurate and experienced chemifts to relinquifh them 


almoft entirely, as there appeared no other likely means of t 


fucceeding but by its means and that of the exhaufted re- 


ceiver. A contrivance to leffen the quantity of mercury 
neceffary for fuch experiments was therefore a defirable ob- 


jet; and by introducing the dome ufed by Mr. Watt in his — 
“hydraulic bellows, I have fucceeded in conftruéting an ap+ — 


paratus in which both of the above-mentioned requifites are 


obtained at a comparatively {mall expence. As it is hardly 
| | poflible 


Defeription of a Mercurial Gazometer. 155 
poflible to japan tin or copper fo perfectly as to prevent their 
being attacked by mercury when brought in contaét with 
them, I had the cylinders turned in hignum vite, on which 
the mercury has no action: the conduéting tube is of glafs 3 
and the cocks aré coated on the infide with varnith. 

The ufefulnefs of an apparatus fo conf{tracted will appear 
fufficiently obvious, when it is recollected that all gafes pafled 
through any other fluid than mereury, watef for inftance, 
take up a quantity of moifture, which adds confiderably to 
their gravity, and makes it impoffible to determine their 


x. real weight. 


' 


- For Pp Pighing of gafes I make ufe of a glafs globe and ftop- 
eock of a fasaller fize than is commonly employed, as greater 
accuracy can be obtained by ufing a proportionally delicate 
beam than by employing a larger globe, which muft be fuf- 
pended to a beam of fuch Giese as greatly to inereafe the 


' friction on its axes. Itis of great importance, in the analyfis 


of bodies, or in other chemical experiments, to be able to 
afcertain with accuracy the weight of any gas obtained by 
the procefs. The weight of two or more quantities of gas 
fhould however be always tried; and the mean be taken to 
prevent any error. 
A, (Plate IIT.) is a reprefentation of the bell of the gazo- 
meter, made of glafs, furnifhed with a cock at top, ach able 


to contain 34 ounces troy of diftilled water. The divifions 


Of capacity, determined by actual meafurement, are marked 
on the glafs with a diamond. BB, fection of two cylinders 
of lignum vite, the outward one {crewed upon the folid in- 


ternal one, which is made to project at its lower extremity, 


and furnifhed with a male fcrew; to work into a female ferew 
with which the lower end of the external cylinder is fur 
nifhed. The fpace between thefe is fo adjufted as to be al- 
moftt filled up by the fubftance of the glafs bell A when 
dropped into it, fo that the quantity of mercury neceflary-to 
fill up that fpace is proportionally fmall. The internal cy- 
linder has a conducting tube up through its axis, the lower 
end of which is furnifhed with a female ferew anfwering to 
the male fcrew of the cock of the {mall receiver C. The re- 
eeiver C is made of glafs, and open at bottom, When this 
tn X 2 receiver 


156 Defcription of a Mercurial Gazometer. 


receiver is ufed, it is ferewed into its place, and refts upon a 
fmal] cup or ciftern of mercury D, in which the beak of a 
retort, furnifhed with a bent glafs tube, to be afterwards no- 
ticed, may be introduced under the receiver, E,E,E,E, fec-' 
tion of a wooden ftand upon which the cylinders of lignum: 
vite are fupported, having an openmg through the top to. 
permut the cock of the receiver C to be joined to the con- 
du@ting tube of the internal cylinder B. The ciftern D is 
adjufted to its height by means of a rifing cylinder in the 
pedeftal F. Gis a transfer glafs for mixing alkaline gafes in 
vacuo, or other purpofes; and, when ufed, is joined to the: 
top of the bell A. H,-a glafs globe and ftop-cock, capable 
of holding 14 ounces troy of diftilled water for weighing 
gafes: it receives its gas by being inverted, and fcrewed inte 
the bell A. I, a bladder furnifhed with a ftop-cock to affitt 
in holding, transferring, or mixing different gafes. K, an 
elaftic gum-bottle, capable of containing 30 ounces of di- — 
filled water, for holding the acid gafes: when ufed, it is 
{crewed into the top of the transfer G; the bottom cock of 
the latter being at the fame time joined to the bell A, previ- 
oufly charged with the alkaline gas: the cocks being turned, 
“the gafes ruth tagether in vacuo. L, a fmall portable air- 
pump, for exhautting the globe H. M,a double male fcrew, 
which fits any part of the apparatus, and on which a valve 
may be faftened. N, a double female ferew. O, a fmall in- 
ftrument, which [ would not have mentioned, had I not found 
it of peculiar fervice in collecting fpilled mercury : it is made 
of glafs, the mouth being applied at @: you may colle&t any 
{mall globules of mercury by the fmall end 4, by which 
means they are elevated into the receiver at Q. It is ufeful 
likewife for removing mercury from the {mall ciftern. 
One of the principal objections to the ufe of mercury im 
fuch experiments as this apparatus is mtended for, has been,. 
the great foree neceflary to overcome the refiftance of a co- 


lumn of mereury when gafes are to be received over that 


denfe fluid; a-refiftance in the proportion of one inch of 
mercury to fourteen inches of water, and which very few 
lutes are able to withftand. «This refiftance I overcome by 
a very fimple contrivance: a bent tube fitted into the beak 


of RY 


5 SR) er 


eed 


* 


On the Preparation of Writing Ink. 137 
# the retort, (if one be employed,) or into a Wolf’s appa- - 
ratus, and pafling into the upper part of the fmall receiver, 
as exprefled in the plate at C. By employing mercury for 
fuch experiments, another advantage is gained by the ule of 
this apparatus, namely, a power of exhauition in the retort, 
or Woltf’s bottle, equal to a column of two inches of mer- 


_ curyy or 28 inches of water: This will be eafily conceived 


when it is recolleéted that, by drawing up the large receiver 
A, the fmall one C is raifed in its ciftern, bearing up with 


* it the contained mercury, which is kept in its place by the 


preffure of the atmofphere on the furface of the mercury in | 
the ciftern. The cock of the fimall receiver C is then to be 
turned off, and that of the large one A to be turned on. The 


_ air, of which the retort, or Wolf’s bottle, i is thus exhaufied, 


may then be let out, by plunging A into the mercury be- 
tween the cylinders BB, and turning off the cock. When 


_a fufficient quantity of gas pafles from the retort, or bottle, 


through the bent tube into C, to level the mercury in it and 
the ciftern, the communication may again be opened, and 


the fame fieps followed as before defcribed. By this means 


I have been enabled to obtain more gas, from the fame ma- 
terials, than if I had received it through a fluid of the weight 
of water; a circumftance of fome importance where nice dud 
accurate peli are looked for. 

The plate of the apparatus is on a {cale of nearly three 
inches to a foot. 


ee 


VUHI. A Communication refpediing the Preparation of Writing 


ee 


Ink. By Mr. DEsORMEAUX junior. 
Mr. Epiror, 


EING a conitant reader of your truly inftruétive and 
entertaining Work, and having noticed in the Number for 
Oétober, p. 29, a communication relative to an improved 
writing ink, Lam, in confequence, induced to offer fome prac- 
tical remarks on that fubject. 

Previous to my reading that communication refpeéting 


the difcoyeries of Prouft having been applied by Van Mons 


to 


448 On ihe Preparation of Writing Ink. a 
to the preparation of the fluid alluded to, I had made a great 
variety of experiments, ih fome of which I treated the ful« 
phat of iron precifely as there directed ; but fince that times 
I have, with a view to improvement, followed the rule which 
is there prefcribed ftriftly, and have befides, at former inter- 
vals, gone over and varied the experiments of Macquer;) 
Lewis, Berthollet, Ribancourt, Prouft, and other celebrated 
chemifts, both foreign and native, who have treated on this 
and other fubjeéts nearly allied to it; with a view, if pof+ 
fible, to eftablith certain data upon which to ground the beft: 
mode of fabricating the article in queftion, being very de- 
firous conftantly to obtain an ink for the common purpofes 
of penmanfhip, which, at the fame time that it fhould flow 
with freedom, fhould have the proper degree of luftre or glof- 
finefs, and be at the moment of ufing intenfely black, with 
a capability of retaining that colour eotifianglie , even though 
openly expofed to the “adtion of the fun and air. This, I 
prefume, I have accomplifhed: at leaft, during a {pace of ten 
years, I have never met with any formula w hand bbe fo well 
rewarded my pains as the one which I am about to. commu- 
nicate. Having been brought up in a line of bufinefs im 
which I am in the daily habit of obferving the aétion of fuch 
fubftances upon each ‘other as enter into the formation of 
ink, it may be readily imagined that, in a practical point of 
view, my opportunities for the improvement of it have fallen 
little thort of any individual whatever. If to this I add, that, 
fince the year 1794, I have annually fupplied the public with 
at leaft 17,000 gallons of ink, befides preparing powder for its. 
oceafional production, it may be inferred that I have fpared 
no pains in ftudying what would beft eonduce to its perfect- 
ability ; and after the many attempts which I have made, I 
have never found my. expectation or that of my friends de= 
ceived, when the procefs has been conducted agreeably to the © 
following direétions :—In fix quaris (beer meafure) of water, 
(it does not appear of importance whether it be rain, river, or 
{pring water,) oz four ounces of the beft Campeachy log= 
wood, chipped very thin acrofs the graim; (the boiling may 
be continued near an hour;) adding from time to time a little - 
boiling water, to compenfate for wafte by evaporation : ftrain 
9 the 


v = 


F On the Preparation of Writing Ink. AS9 


the liquor whil/? hot, fuffer it to cool, and make up the 
quantity equal to five quarts by the further addition of cold 
water. To this cold decoétion put one pound averdupois 
weight of blue galls, or 20 ozs. of the beft galls in forts, 
which fhould Be firft rasan bruifed; 4 ozs. of fulphat of 
iron, calcined to whitenefs;. 4 oz. of the acetite of copper, 
which fhould be triturated in a mortar, moiftened by a little 
of the deco&tion gradually added till it be brought to the - 
form of a fmooth palte, and then thoroughly intermixed with 
the whole mafs. Three ounces of coarfe brown fugar, and fix 
ounces of good gum Senegal, or Arabic, are alfo to be added. 
Thefe feveral ingredients may be introduced one after the 
other immediately, contrary to the advice of fome, who re- 
- commend the gum, &c. to be added when the ink is nearly 
- made; as gum, ew ever, 1s at prefent exorbitantly dear, three 
or four ounces will be found fufficient, with only one and an 
half ounce of fugar, unilefs, for particular purpofes, it is wanted 
_ to beara higher glofs than common. In regard to the ufe 
of fugar, which f have here recommended, I hope I fhall not 
 ‘trefpafs in remarking, that my obfervations, on a very exten- 
- five feale, are coincident with thofe of M. Ribancourt, who 
 fays, that a degree of fluidity is by its means imparted, which 
_ allows the dofe of gum to be enlarged confiderably beyond 
_ what it would bear without it; and it is thereby rendered 
_ lefs liable to clog the pen, which, efpecially when the nib is 
' very fine, if it does not flow freely, quits it fo flow as unplea~ 
fantly to retard the writer, and is totally unfit for fine manu- 
_ feripts; befides, by fuch an union of gum and fugar, a de- 
_ gree of confiftency is given to the liquor, which enables it to 
 fafpend a much greater portion of colouring matter than 
otherwife could be effected; a circumiftance of the greateft 
importance to its hue and permanency. © It is far from my 
_ defign, in thus tranfmitting my ideas, to induce a fuppofition 
that it is eaaét/y after this manner that I, or any other perfon 
_ who fupply ink by wholefale, compound it; fo far from it, 
- that the firft coft of one gallon, on the plan here fuggefted, 
_ would exceed twice the fum which: is ufually paid for it to 
the manufacturer, although by retail it is difpofed of at an 
_ €normous rate, For private perfons, cc who with to 
be 


160 On the Preparation of Writing Ink. 


be particular in their manufecripts, the rule I have here baid 
down will be found fully to anfwer their expectations at @ 
cheaper rate than they are in general furni{hed with it, The 
beft veftel, in my opinion, in which to make ink, ts a come 
mon ftone bottle, which will contain half as much more as 
is propofed to be made, and which fhould be agitated twice 
a day, and be left uncorked, in order to expofe frefh furfaces 
of the liquor to the action of the air, without which it can- 
not be expected to write very black when firft ufed, but with 
this precaution may be fit for ufe in about 14 days; when 
it may be poured from its dregs, and soem up, to preferve it 
from duft, as well as wafle by evaporatidn. In cold weather 
it fhould never be fuffered to freeze, which is found to caule 
a difunion of its parts, nor does it ever afterwards recover 11s 
former intenfity of colour, luftre, or durability. Many per- 
fons, I am aware, difapprove, and therefore omit the ufe of 
Joewood, from an apprehenfion that it induces a tendency in 
the ink to fade; this however, from the ftricteft attention, I 
can affert' to be fallacious, at leaft where it is not had recourfe 
to by way of fubftitute for the other more expenfive articles ; 
indeed its effets are quite the reverfe, where all the ingredi-: 
ents are properly proportioned. As to the beautiful complexion 
which is given by it to the entire mafs of fluid, it would be 
needlefs to infift, unlefs for the fake of thofe who are unac- 
quainted how a mixture of the acetite of copper and logwood 
liquor work together, and by which, in this inftance, a rich- 
nefs and bloom is given, which can in no other way be got 
with equal economy and fuccefs; independent of which, the 
colouring matter of the wood, by its affinity with the oxyde 
of ivon, has a very powerful effect to blacken the ink, and 
to render it lefs capable of change from any unfaturated acid 
in the fulphat of iron, or from the operation of the air, I 
am aware, too, that the introduétion of cupreous matter has 
been objeéted to, on the fcore of its mjuring the penknife by 
a portion of copper attaching itfelf thereto in confequence of 
fuperior elective attraétion, whereby it has been remarked 
that a part of the knife’s edge is diflolved, and a quantity of 
copper aniwering thereto is exchanged and depofited in its 
place, which is always faid to happen when the pen retains 

a little 


On the Preparation of Writing Ink. 16 


a hittle ink at the time of its being mended. This, I think, 


is {pinning out .the effet of chemical affinity too far; for 
although, with refpet to tke reafoning, the truth mutt be 
admitted, I contend, notwithftanding, that its confequences 
to the edge are net apparent te the eye; nor is any fenfible 
detrimental change thereby produced upon the knife, more 
than what is induced by any other ank into which neither 
the fulphat or the acetite of copper is introduced. As to 
miyfelf, however, I have never yet feen a receipt for the form~- 
ation. of ink, where each of the principles were fo.completely 
proportioned and faturated with each other as to be inert 
when applied to the furface of a piece of polithed metal, 
fuch as iron, for example; nay, even the frequent contact of 
water only, if allowed to remain, would {poil any inftrament 
made of that material. I fhall not enlarge on this particular, 
conceiving the moft powerful objection I can offer in oppofi- 
tion to that opinion, is, that I have now lying by me a 
penknife, which has been in conftant ufe between two and 
three years, and which even yet retains almoft as good an 
edge as it had at firft, by the mere affiftance of an unprepared 
leather ftrap, although in the ink with which I write the 
acetite of copper has always been ufed. But even admitting, 
for argument’s fake, that what I have attempted to difprove is 
true, how many hundred pens might be made and mended 
ere it would be requifite to beftow twopence to the-cutler for 
the exercife of his art? In fhort, if the introduétion of the 
fubftance alluded to into ink be a fault, I confider it as one of 
no confequence when put in competition with the advantages 
of beauty, durability, and intenfity of colour imparted by it. 
I fhall intrude no“longer on the time or patience of your 
readers, than by requefting, if any of them are pofleffed of a 
cheap and efficacious method whereby the mouldinefs of ink 


may be prevented, that they will communicate the fame 


through the medium of your Magazine, in doing which 2 
very confiderable fervice will be rendered towards its perfeét- 
ability. The admixture either of a {mall quantity of the 


-muriate of foda, of the’ nitrate of pot-afh, of alcohol, or of 


cloves, have been feverally recommended for this purpofe; 
; t by experience I know that of thefe oily alcohol will 


‘a, Vou. V. ® avail, 


162 An Inquiry concerning the 
avail, and this cannot be added in fufficient quantity without 
caufing it to fink into, and fpread upon the paper; fo that, 
sideeui its ufe is altogether interdiéted. The beft plan which 
{ have Hitherto found as a preventive to the vegetative pro- 
cefs I here allude to, is, to add the ingredients of which the 
ink is compofed to the cold decoétion 5 if recourfe be had to 
boiling, ALL together, it is found very rapidlv to promote the 
itt aise h's ; and were ebullition totally avoided, it would 
on that account be better, but then we could not obtain the 
ink of fo deep a colour; yet I know of no inftance in which 
mouldinefs wiil not appear in time, and that in no inconfider- 
able degree. In fine, I am ignorant of any fubftance, or me- 
-thod, that has been hitherto ufed as a fpecific to remedy the 
 defe&t. If there is any that can be fuggefted, I fhould be 
happy to put it to the teft of experiment. 
Iam, Sir, yours, &c. 


L. DESORMEAUX jun, 
No. 8, Vine Court, Spitalfields. : 


. 


IX. An Inguiry concerning the Weight afcribed to Heat. | By 
BensaAmMin Count Rumrorp, F.R.S.M.R.LA. &e, 
Read before the Royal Sogiety May 2, 1799. 


"Tue various experiments which have hitherto been 
made with a yiew to determine the queftion fo long agi- 
tated, relative to the weight which has been fuppofed to be 
gained, or to be loft, by bodies upon their being heated, 
are of a nature fo very delicate, and are liable to fo many © 
errors, not only on account of the imperfections of the in- 
framents made ufe of, but alfo of thofe, much more difficult 
to appreciate, arifing from the vertical currents in the atmo- 
fphere, eaufed by the hot or the cold body which is placed 
in the balance, that it is not at all furprifing that opinions 
have been fo much divided relative to a faét fo very difficult 
to afcertain. 

Yt is'a confiderable time fince I firft began to rexeaipine on 
this fubje&, and I have made many experiments with a view 
so its inveftigation; and in thefe experiments | have taken 


all 


Weight afcribed to Heat. 163 


all thofe precautions to avoid errors, which a knowledge of 
the various fources of them, and an earneft defire to deter~ 
mine a fa& which I conceived to be of importance to be 
known, could infpire: but though all my refearches tended 
to convince me, more and more, that a body acquires no ad~ 
ditional weight upon being heated, or rather, that heat has no 
effect whatever upon the weights of bodies, I have been fo 
fenfible of the delicacy of the 1 inquiry that I was for a long 
time afraid to form a decided opinion upon the fubject. 

Being much. ftruck with the experiments recorded in the 
Tranfactions of the Royal Society, Vol. LXXV. made by 
Dr. Fordyce, upon the weight faid to be acquired by water 
upon being frozen; and being poffefled of an excellent ba- 
lance, belonging to his moft Serene Highnefs the Ele¢tor 
Palatine Duke of Bavaria, early in the beginning, of the 
winter of the year 1787 (as foon as the cold was fufficiently 
intenfe for my purpofe) I fet about to repeat thofe experi-+ 
ments, in order to convince myfelf whether the very | extraor- 
dinary fa& related might be depended on; and with a view 
to removing, as far as was in my power, every fource of error 
and deception, I proceeded in the following manner :— 

Having provided a number of glafs bottles, of the form and 
fize of what in England is called a Florence flafk (blown as 
thin as poffible) and of the fame fhape and dimenfions, I 
chofe out from amongft them two, which, after ufing every 
method I could imagine of comparing them together, ap- 
peated to be fo much alike as hardly to be diftinguifhed. 

Into one of thefe bottles, which I {hall on AS put 
4107,86 grains troy of pure diftilled water, which filled it 
about half full; and into the other, B, I put an equal weight 
of weak fpirit of wine; and, fealing both the bottles her+ 
metically, and wafhing them and wiping them perfectly 
elean and dry on the outfide, I fufpended them to the arms 
of the balance, and placed the balance in a large roomy 
which for fome weeks had been regularly heated every: 
day by a German ftove, and in wliich the air was kept up 
to the temperature of 61° of Fahrenheit’s thermometer, with 
very little variation. Having fuffered the bottles, with their 
contents, to remain in this fituation till I conceived they 

¥-2 mutt 


164 An Inquiry concerning the 


muft have acquired the temperature of the circumambient 
air, I wiped them afrefh with a very clean dry cambric 
handkerchief, and brought them into the moft exaé equi- 
librium pofhible, by attaching a fmall piece of very fine filver 
wire to the arm of the balance, to which the bottle which | 
was the lighteft was fufpended. 

Having fuffered the apparatus to remain in this fituation 
about twelve hours longer, and finding no alteration in the - 
relative weights of the bottles, (they continuing all this time 
to be in the moft perfeét equilibrium,) I now-removed them 
into a large uninhabited room fronting the north, in which 
the air, which was very quiet, was at the temperature of 
29° F., the air without doors being at the fame time at 27°3. 
and, going out of the room, and locking the door after me, 
t fuffered the bottles to remain forty-eight hours, undifturbed, 
in this cold fituation, attached to the arms of the balance as: 
before. 

At the expiration of that time I entered the room, ufing. 
the utmoft caution not to difturb the balance, when, to my 
great furprife, I found that the bottle A very fenfibly pre- 
ponderated. 

The water which this bottle contamed was completely 
frozen into one folid body of ice; but the fpirit of wine, in’ 
the bottle B, fhewed no figns of freezing. 

I now very cautioufly reftored the equilibrium, by adding - 
fmall pieces of the very fine wire of which gold lace is made, 
to the arm of the balance to which the bottle B was fuf- 
pended, oe I found that the bottle A had augmented its 
weight by +-3>5; part of its whole weight at the beginning 
of the experiment ;. the weight of the bottle with its contents: 
having been 4811,23 grains troy, (the bottle weighing 703,34" 
erains, and the water 4107,86 grains,) and it requiring now 
34, parts of a grain, added to the oppofite arm of the ba- 
lance, to counterbalance it. 

Having had occafion juft at this time to write to my friend, 
Sir Ghats Blagden, upon another fubject, I added a poft- 
fcript to my letter, giving him a fhort account of this expe- 
ment, and telling him how “ very contrary to my expeétation’’ 
the vefult of it had turned out: but I foon after found that ¥ 

hac 


6 


Ce ee ee eee ee 
‘ 


Weight afcribed to Heat. 163 
had been too hafty in my communication. Sir Charles, ix 
his anfwer to my letter, expreffed doubts refpecting the fact; 
but, befere his letter had reached me, I had learned,. from 
my own experience, how very dangerous it is, in philofo- 
phical inveftigations, to draw conclufions from fimgle expe- 


riments. 


- Having removed the balance, with the two bottles attached ° 
to it, from the cold into the warm reom, (which ftill remained 
at the temperature of 61°,) the ice in the bottle A gradually 
thawed; and being at length totally reduced to water, and 
this water having acquired the temperature of the furround- 
ing air, the two bottles, after being wiped perfectly clean and 
dry, were found to weigh as at the beginning of the experi- 
ment before the water was frozen. 

This experiment, being repeated, gave nearly the fame re- 
fult, the water appearing, when frozen, to be heavier than 
in its fluid ftate; but fome irregularity in the manner in 
which the water loft the additional weight which it had ap- 
peared to acquire upon being frozen, when it was afterwards 
thawed, as alfo a fenfible difference in the quantities of 
weight apparently acquired in the different experiments, led 
me to fufpe& that the experiment could not be depended or 
for deciding the fact in queition: I therefore fet about to 
repeat it, with fome variations and improvements :—but, be- 
fore I give an account of my further inveftigations relative to 
this fubje&t, it may not be amifs to mention the method 1 
purfued for difcovering whether the appearances mentioned 
in the foregoing experiments might not arife from the im- 
perfections of my balance; and it may likewife be proper to 
give an account, in this place, of an intermediate experiment 
which I made, with a view to difcover, by a fhorter route, 
and in a manner lefs exceptionable than that above-men- 
tioned, whether ‘bodies actually lofe, or acquire, any weiglit, 
upon acquiring an additional quantity of latent heat. 

My fufpicions refpeéting the accuracy of the balance arofe 
from a knowledge (which I acquired from the maker of it} 
of the manner in which it was conftructed. 

The three principal points of the balance having been de- 
termined, as nearly as poffible, by meafurement, the axes of 

‘ 7 | motion 


166 An Inquiry concerning the 

motion were firmly fixed in their places in a right line, and 
the beam being afterwards finifhed, and its two arms brought 
to be in equilibrio, the balance was proved by fufpending 
weights, which before were known to be exactly els to 
the ends of its arms._ 

If with thefe weights the balance remained in equilibrio, it 
was confidered as a proof that the beam was juft ; but, if oné 
arm was found to preponderate, the other was gradually 
lengthened, by beating it upon an anvil, until the difference 
ef the lengths of the arms was reduced to nothing, or until 
equal weights, fufpended to the two arms, remained in equi- 
Kbrio; care being taken, before each trial, to bring the two 
ends of the beam to be in equilibrio, by reducing, with the 
file, the arm which had been lengthened. 

Though in this, method of conftruéting balances the moft 
perfect equality in the lengths of the arms may be obtained, 
and confequently the greateft poffible accuracy, when ufed at 
' atime when the temperature of the air is the fame as when 
the balance was made; yet, as it may happen that, in order 
to bring the arms of the balance to be of the fame length, 
ene of them may be much more hammered than the other, 
I fufpected it might be poffible that the texture of the metal 
forming the two arms might be rendered fo far different by 
this operation as to occafion a difference in their expanfions 
with heat ; and that this difference might occafion a fenfible 
error in the balance, when, being charged with a great 
weight, it fhould be expofed to a confiderable change of 
temperature. 

o determine whether the apparent augmentation of 
weight, in the experiments above related, arofe in any de- 
gree from this caufe, I had only to repeat the experiment, 
caufing the two bottles A and B to change places upon the 
arms of the balance; but, as I had already found a fenfible 
difference in the refults of different repetitions of the fame 
experiment, made as nearly as poffible under the fame cir- 
eumftances, and as it was above all things of importance to 
afcertain the accuracy-of my balance, I preferred making a 
particular experiment for that purpofe. 

My firft idea was, to lufpend to the arms of the balance, by 

very 


Weight afcribed to Heat. 167 


very fine wires, two equal globes of glafs filled with mer- 
¢eury, and, fuffering them to remain in my room till they 
fhould have acquired the known temperature of the air im it, 
to have removed them afterward into the cold, and to have 
feen if they ftill remained in equilibrio under fuch difference 
ef temperature: but, confidering the obftinacy with which 
moifture adheres to the furface of glafs, and being afraid 
that fomehow or other, notwithflanding all my precautions, 
one of the globes might acquire or retain more of it than the 
other, and that by that means its apparent weight might be 
increafed ; and having found, by a former experiment, of 
which I have already had the honour of communicating an 
account to the Royal Society, that the gilt furfaces of metals 
do not attract moifture; inftead ale vlafs clobes filled with 
mercury, I made ufe of two equal folid globes of brafs, well 
gilt and burnifhed, which I fufpended to the arms of the 
balance by fine gold wires. 

Thefe globes, which weighed 4975 grains each, being 
wiped perfe€tly clean, and having acquired the temperature 
{61°) of my room, in which they were expofed more than 
twenty-four hours, were brought into the moft ferupulous 
equilibrium, and were then removed, attached to the arms 
of the balance, into a room in which the‘air was at the tem- 
perature of 26°, where they were left all night. 

The refult of this trial furnithed the mow fatisfactory proof! 
of the accuracy of the balance; for, upon entering the room, 
I found the equilibrium as perfect as at the beginning of the 
experiment. 

Having thus removed my doubts refpecting the accuracy 
of my balance, I now refumed my inveftigations relative to 
the augmentation of weight which fluids have been faid to 
acquire upon being congealed. 

In the experiments which I had made, I had, as I then 
imagined, guarded as much as poflible againft every fource 
of error and deception. The bottles being of the fame fize, 
neither any oecafional alteration in the preflure of the atma- 
fphere during the experiment, nor the neceflary and unavoid- 
able difference in the denfities of the air in the hot and in 
the cald rooms in which they were weighed, could affegét 

their 


: 


168 an Inquiry concerning the 


their apparent weights; and their fhapes and their quantities 
of furface being the fame, and as they remained for fuch a 
confiderable length of time in the heat and cold to which 
they were expofed, I flattered myfelf that the quantities of. 
moifture remaining attached to their furfaces could not. be fo 
different as fenfibly to effect the refults of the experiments, 
But, in regard to this laft circumftance, F afterwards found 
reafon to conclude that my opinion was erroneous. 

Admitting the fact ftated by Dr. Fordyce, (and which my 
experiments had hitherto rather tended to corroborate thar 
to contradiét,) I could not conceive any other caufe for the 
augmentation of the apparent weight of water, upom its being 
frozen, than the lofs of fo great a proportion of its latent 
heat as that fluid is known to evolve when it congeals; and 
I concluded, that if the 18 of latent heat added to the weight 
of one body, it muft of neceffity produce the fame effect on 
another, and confequently, that the augmentation of the 
quantity of latent heat muft, in all bodies, and in all cafes, 
diminith their apparent weights. od 

To determine whether this is actually the cafe or not, I 
made the following experiment :— 

Having provided two bottles, as nearly alike as poffible, 
and im all refpects fimilar to thofe made ufe of in the exper 
riments above-mentioned, inte one of them I put 4012,46 
grains of water, and into the other an equal weight of mer- 
eury; and fealing them hermetically, and fufpending then 
to the arms of the balance, I fuffered them to acquire the 
temperature of my room, 61°; then, bringing them into a, 
perfect equilibrium with each other, I removed them into a 
room in which the air was at the temperature of 34°, where 
they remained twenty-four hours. But there was not the leat 
appearance of either of them acquiring or lofing any weight. 

Here it is very certain that the quantity of heat loft by the 
water muft have been very confiderably greater than that loft 
by the mercury, the fpeeific quantities of latent heat in water 
and in mereury having been determined to be to each other 
as 1000 to 333 but this difference in the quantities of heat 
jof, produced no fenGible difference on the weights of the 
-fiuids in- quefijon, > asl 
Tee Had 


Weight afcribed to Heat. 169 

Had any difference of weight really exifted, had it been no 
more thant ove millionth part of the weight of either of the 
fluids, I fhould certainly have difcoyered it; and, had it 
amounted to fo much as +5254 part of that weight, I fhould 
have been able to have meafured it: fo fenfible, and fo very 
accurate, is the balance which I ufed in thefe experiments. 

I was now much confirmed in my fufpicions, that the ap- 
parent angmentation of the weight of the water upon its 
being frozen, in the experiments before related, arofe from fome 
accidental caufe; but I was not able to conceive what that 
caufe could poffibly be,—unlefs it were either a greater quantity 
of moifture attached to the external furface of the bottle 
which contained the water, than to the furface of that con- 
taining the fpirits of wine,—or fome vertical current or cur- 
rents of air, caufed by the bottles, or one of them, not being 
“exactly of the temperature of the furrounding atmofphere. 

Though I had forefeen, and, as I thought, guarded fuffi- 
ciently aguinft thefe accidents, by making ufe of bottles of 
the fame fize and form, and which were blown of the fame 
kind of glafs, and at the fame time, and by fuffering the bot- 
tles in the experiments to remain for fo confiderable a length 
of time expofed to the different degrees of heat and of cold, 
which alternately they were made to acquire; yet, as I did 
not know the relative conducting powers of ice, and of {pirit 
of wine, with re{pect to heat; or, in other words, the degrees 
of facility or difficulty with which they acquire the tempera- 
ture of the medium in which they are expofed, or the time 
taken up in that operation; and, confequently, was not ab/fo- 
lutely certain as to the equality of the temperatures of the con- 
tents of the bottles at the time when their weights were com- 
pared, I determined now to repeat the experiments, with fuch 

variations as fhould put the matter in queftion out of all 
doubt. 

I was the more anxious to affure myfelf of the real tempe- 

ratures of the bottles and of their contents, as any difference 
in their temperatures might vitiate the experiment, not only 
by caufing unequal currents in the air, but alfo by caufing, 
at the fame time, a greater or lefs quantity of moifture to | 
remain attached to the glafs. | 
Vou. V. Z Re 


» 


170 | An Inquiry concerning the 


To remedy thefe evils, and alfo to tender the experiment 
tore ftriking and fatisfactory in other refpects, I proceeded 
in the following manner :— 

Having provided three bottles, A, B, and C, as nearly 
alike as poffible, and refembling in all refpects thofe already 
defcribed ; into the firft, A, I put 4214,28 grains of water, 
and a {mall thermometer, made on purpofe for the experi- 
ment, and fufpended in the bottle in fuch a manner that its 
bulb remained in the middle of the mafs of water; into the 
fecond bottle, B, I put a like weight of fpirit of wine, with a 
like thermometer; and, into the bottle C, I put an equal 
weight of mercury. 

Thefe bottles, being all hermetically fealed, were placed 
in a large room, in a corner far removed from the doors and 


windows, and where the air appeared to be perfeétly quiet; - 


and, being fuffered to remain in this fituation more than 


twenty-four hours, the heat of the room (61°) being kept up 


all that time with as little variation as poflible, and the con- 
tents of the bottles A and B appearing, by their inclofed 


thermometers, to be exactly at the fame temperature, the 


bottles were all wiped with a very clean, dry, cambric hand- 


kerchief; and, being afterwards fuffered to remain expofed 


to the free air of the room a couple of hours longer, in order 
that any inequalities in the quantities of heat, or of the moif- 
ture attached to their furfaces, which might have been occa- 
fioned by the wiping, might be corrected by the operation 
of the atmofphere by which they were furrounded, they were 
all weighed, and were brought into the moft exact equili- 


brium with each other by means of {mall pieces of very fine. 


filver wire attached to the necks of thofe of the bottles which 
were the lighteft. 

This being done, the bottles were all neve into a room 
in which the air was at 30°, where they were fuffered to re- 
main, perfectly at reft and undifturbed, forty-eight hours ; 
the bottles A and B being fufpended to the arms of the ba- 
lance, and the bottle C fufpended, at an equal height, to the 
arm of a ftand conftruéted for that purpofe, and placed as 
near the balance as poffible, and a very fenfible thermometer 
fufpended by the fide of it. 

At 


“ 


Weight afcribed to Heat. 71 


At the end of forty-eight hours (during which time the 
apparatus was left in this fituation) I entered the room, open- 
ing the door very gently for fear of difturbing the balance; 
when I had the pleafure to find the three thermometers, viz. 
that in the bottle A, which was now inclofed in a folid cake 
of ice, that in the bottle B, and that fufpended in the open 
air of the room, all ftanding at the fame point, 29° F., and 
the bottles A and B remaining in the moft perfect equilibrium. 

To affure myfelf that the play of the balance was free, I 
now approached it very gently, and caufed it to vibrate; and 
T had the fatisfaction to find, not only that it moved with 
the utmoft freedom, but alfo, when its vibration ceafed, that 
it refted precifely at the point from which it had fet out. 

I now removed the bottle B from the balance, and put the 
bottle C in its place; and I found that ¢dat likewife remained 
of the fame apparent weight as at the beginning of the expe: 
riment, being in the fame perfec equilibrium with the bot- 
tle A as at firft, 

I afterwards removed the whole apparattis into a warm 
room, and, caufing the ice in the bottle A to thaw, and fuf- 
fering the eee. bottles to remain till they and their contents 
had acquired the exact temperature of the furrounding air, I 
wiped them very clean, and, comparing them together, I 
found their weights remained unaltered. 

This experiment I afterwards repeated feveral times, and 
always with precifely the fame refult; the water, zm no in- 
fiance, appearing to gain or to lofe the leaft weight upon 
being frozen, or upon being thawed; neither were the rela- 
tive weights of the fluids in either of the other bottles in the 
leaft changed, by the various degrees of heat, and of cold, to 
which they were expofed. 

If the bottles were weighed at a time when their contents 
were not precifely of ihe fume temperature, they would fre- 
quently appear to have gained, or to have loft, fomething of 
their weights; but this doubtlefs arofe from the vertical cur- 
rents which they caufed in the atmofphere upon being heated 
or cooled in it; or to unequal quantities of moifture attached 
to the furfaces of the bottles; or to both thefe caufes ope- 


rating together, 
Zo As 


sgt! 
aM an 


17m An Inquiry concerning the © 


As I knew that the conduéting power of mercury, with 
refpeét to heat, was confiderably greater than either that of 
water or that of fpirit of wine, while its capacity for receiv- 
ing heat is much lefs than that of either of them, I did not 
think it neceffary to inclofe a thermometer in the bottle C, 
which contained the mercury; for it was evident that when 
the contents of the other two bottles fhould appear, by their 
thermometers, to have arrived at the temperature of the me- 
dium in which they were expofed, the contents of the bottle 
C could not fail to have acquired it alfo, and even to have 
arrived at it before them; for, the time taken up in the heat- 
ing or in the cooling of any body, is, cateris paribus, as the 
capacity of the body to receive and retain heat direé#ly, and 
as its conduéting power inver/ely. 

The bottles were fufpended to the balance by filver wires, 
about two inches long, with hooks at the ends of them ; and, 
in removing and changing the bottles, I took care not ta 
touch the glafs. I likewife avoided, ypon all occafions, and 
particularly in the cold room, coming near the balance with, 
my breath, or touching it, or any part of the apparatus, with 
my naked hands. 

Having determined that water does not acquire or lofe any 
weight upon being changed from a ftate of fluidity to that of 
ice, and vice verfd, I fhall now take my final leave of a fub- 
je&t which has long occupied me, and which has coft me 
much pains and trouble ; being fully convineed, from the 
refults of the above-mentioned experiments, that if heat be 
in fact a fubjlance, or matter, (a fluid /wi generis, as has been 
fuppofed,) which, paffing from one body to another, and 
being accumulated, is the immediate caufe of the pheno- 
mena we obferve in heated bodies, (of which, however, I 
cannot help entertaining doubts,) it muft be fomething fo 
infinitely rare, even in its moft condenfed ftate, as to baffle all 
our attempts to difcover its gravity. And, if the opinion which 
has been adopted by many of our ableft philofophers, that 
heat is nothing more than an inteftine vibratory motion of 
the conftituent parts of heated bodies, fhould be well founded, __ 
it is clear that the weights of bodies can in nowife be affected 


by. fuch motion. Py 
. I @ 


. 


Veight afcribed to Hea. 194 


Tt is, no doubt, upon the fuppofition that heat is.a fub- 
ftance diftinét from the heated body, and which is accumu, 
lated in it, that all the experiments which have been under. 
taken with a view to determine the weight which bodies have 
been fuppofed to gain, or to lofe, upon being heated or cooled, 
have been made; and upon this fuppofition (but without, 
however, adopting it entirely, as I do not conceive it to be 
fufficiently proved,) all my refearches have been direéted. 

The experiments with water, and with ice, were made in 
a manner which I take to be perfectly unexceptionable; in 
which no foreign caufe whatever could affect the refults of 
them; and the quantity of heat which water is known to 
part with, upon being frozen, is fo confiderable, that if this 
lofs has no effect upon its apparent weight, it may be pre- 
fumed that we {hall never be able to contrive an experiment 
by which we can render the weight of heat fenfible. 

Water, upon being frozen, has been found to lofe a quan- 


tity of heat amounting to 140 degrees of Fahrenheit’s ther- 


ynometer; or, which is the fame thing, the heat which a 
given quantity of water, previoufly cooled to the temperature 
of freezing, actually lofes, upon being changed to ice, if it 
were to be imbibed and retained by an equal quantity of 
water, at the given temperature, (that of freezing,) would 
heat it 140 degrees, or would raife it to the temperature of 
(32° + 140) 162° of Fahrenheit’s thermometer, which is 
only 60° fhort of that of boiling water; confequently, any 
given quantity of water, at the temperature of freezing, upon 
being actually frozen, lofes almoft as much heat as, added 
to it, would be fufficient to make it boil. 

It is clear, therefore, that the difference in the quantities 
of heat contained by the water in its fluid ftate, and heated 
to the temperature of 61° F., and by the ice, in the experi- 
ments before-mentioned, was a¢ Jea/? nearly equal to that 
between water in a {tate of boiling, and the fame at the tem- 
perature of freezing. 

But this quantity of heat will appear much more confider- 
able, when we confider the great capacity of water to confain 
heat, and the great apparent effect which the heat that water 
ees upon being ‘frozen would produce, were it to be im- 

bibed 


174 Experiments made at the Polytechnic School . 


bibed by, or communicated to, any body whofe power of 
receiving and retaining heat is much lefs. . 

The capacity of water to receive and retain heat, or what 
has been called i its fpecific quantity of latent heat, has been 
found: to be to that of gold as 1000 to 50, or,as 20 to 15 
confequently, the heat which any given quantity of water 
lofes upon being frozen, were it tobe communicated to an 
equal weight of gold at the temperature of freezing, the 
gold, inftead of being heated 162 degrees, would be heated 
140 X 20= 2800 degrees, or would be railed to a brigh# rea 
heat. 

It appears therefore to be clearly proved, by my experi- 
ments, that a quantity of heat equal’to that which 4214 
grains (or about g? oz.) of gold would require to heat it from 
the temperature of freezing water to be red hot, has no fenfible 
effect upon a balance sip-Aaan of indicating fo fmall a varia- 
tion of weight as that of -~52>cs5 part of the body im quef- 
tion; and if the weight of gold is neither augmented nor 
leffened by one millionth part, upon being heated from the 
point of freezing water to that of a bright red beat, I think 
we may very fafely conclude, that ALL ATTEMPTS TO 
DISCOVER ANY EFFECT OF HEAT UPON THE APPA- 
RENT WEIGHTS OF BODIES WILL BE FRUITLESS. 


X. Extra& from the Report re[pedling Experiments made at 
the Polytechnic School in the Years V. and V1. on the Come 
bufiton of the Diamond. By C. Guyton. 


[Concluded from Page 61. ] 


Repetition of the Experiment in Fruétidor, Year FT, 


Averer examining what means were moft proper for pre- 
venting the veffels from cracking by the inequality of their 
ution it was found that there were none more certain 
than to employ, inftead of a glafs bell, a well-chofen globe 
of a moderate thicknefs, and of fuch a fize that its farkine 


‘might be at a fufheient diftance from the point of the lumis - 


mous cone. 


’ ~ The 


\ 


> Gees 


ex the Combuftion of the Diamond. 178 
The globe which we judged beft for anfwering thefe con- 


ditions was 28°63 centimetres in diameter: its content was 
123°25 decilitres, or 12,325 cubic centimetres, comprehend- 
ing that portion of the neck which it was thought proper to 
retain, and which was 159 millimetres. That we might the 
more eafily obferve the rifing and falling of the mercury in 
the infide, and thence determine the volumes of gas, we ce- 
mented on the outfide flips of paper, on which we traced, 
by means of meafured veffels, fcales indicating decilitres, or 
or 100 cubic centimetres. : 

It may be readily conceived, that it was not potible to fill 
fo frail a veffel with mercury in order to difplace it afterwards 
by oxygen gas. In transferring the gas by means of water, 
we fhould have been obliged to leave a portion of that liquid 
on the interior fide of the veflel. We determined, therefore, 
to conyey the gas, at the moment when it was difengaged 
from the oxygenated muriat of pot-afh, by means of a tube 
adapted to the diftilling apparatus, and made to defcend to the 
bottom of the globe in fuch a manner that the common air 
fhould be forced to iffue from the globe by another pipe fixed 
in the ftopper of the orifice, and communicating with the 
pneumatic tub. 

This procefs is exaétly the inverfe of that which I propofed 
in my work on aéroftats *, to fill a balloon of inflexible mat- 
ter with hydrogen gas. It was founded on the fame princi- 


ple—the difference of the fpecific gravity of the two fluids. 


Here it had the advantage of leaving the veflel perfectly clean; 
an important condition, and which it is fo difficult to obtain 
when air is expelled by mercury. 

It was readily forefeen that the firft portions of the oxygen 
gas would become mixed with the atmofpheric air, and that 
it would be neceffary to difplace this mixture feveral times by 
new quantities of oxygen gas, that no more azotic gas might 
remain in it, or, at leaft, that the remaining quantity fhouid 
be fo fmall as to be incapable of having a fenfible effect on 
the refults of the experiment. We had even contriyed means 
to determine it, by receiving under the pneumatic bell the 


* Defcription de l’aéroftat de Dijon, &c. 
- aft 


. 


456 Experiments made at the Polytechnic Schoot 


Jaft portions difplaced, that we might fubjeét them to a — 


eudiometric proof. 


With this view we employed 18 decagrammes (about fix 


ounces) of the oxygenated muriat of pot-afh, which were put 
into a retort, at once to furnifh, at one operation, the wholé 
quantity of the gas neceffary for this renewal. 

Thofe who havé not tried themf€lves' this method of fub- 
ftituting one aériform fluid for another, might entertain fome 
doubt refpecting the purity of that employed in our experi- 
ment; but it will be ealy for me to remove it. ‘This was an 
article of fo much importatice that we could not neglect at- 
tempting to colleé proofs of it. 

We know with what fuccefs M. Humboldt applied to the 
improvement of eudiometry, ‘The intereft which he took in 
our experiment induced me to invite him to come and deter- 
mine himfelf with thofe inftruments, and by thofe proceffes, 
which were familiar to him, the purity of the oxygen gas in 
which the combuftion was to take place. He readily ac- 
cepted my invitation, as I had reafon to expeét, from his well 
known zeal for the progrefs of fcience; and this article of 
our report is the production of his pen. I-had likewife the 
fatisfaction of fecing him apply eudiometric inftruments to 
the examination of the refiduum of the gas after the com- 
buttion. The following is the refult of the proofs to which 
he fubjeéted that introduced into the apparatus to ferve far 
the combuftion:— 

Nitrous gas, difengaged, by means of copper, from weak 
nitric acid, was tried’ with fulphat of iron and oxygenated 
muriatic acid, which fhewed in it from o’og to 0'10 of azot. 
One hundred parts of oxygen gas received, towards the mid- 
dle of the operation, as it iffued from the globe, in which we 
had propofed to difplace; in fucceffion, common air by oxygen 
gas, were mixed with 300 parts of this nitrous gas: there 
was an aériform refiduum of 0°66: making allowance for 
027 or 0°30 of azot, pre-exifling in the nitrous gas, we 
judged that, in 100 parts of gas tried, there were flill 36 of 
azotic gas. 

We then continued to introduce into the globe frefh oxy- 
gen gas. We colle&ted towards the end a portion which was 

- 9 ; fubjected 


ee 


+ Boe 
ow 


ae 


on the Combuftion of the Diaindnd. 299 


fubjected tu the fame proof, in the fame proportions, with 
the fame nitrous gas. The refiduum this time was only 30 
"parts ; and as the 300 of nitrous gas employed cdutanaie 
“nine or ten parts for 2 of azot, we eonlased that this oxy- 
gen gas was quite pure,+=Thele are the words of M. Hum- 
boldt. 

When this firft donna” was fulfilled, the queftion chest 
was to place, iri the centre of this globe, the diamond def- 
tined for the experiment. We had previoufly formed a fmall 
cup of the lower portion of a furnace-pipe, the tube of which, 
five centimetres in length, was fixed to an iron ftalk, and this 
ftalk was {tuck into a cylinder of cork deftined to be inferted 
in the neck of the balloon. This cork was dipped in matftic 
to fhut its pores, and a {mall glafs tube pafled through it to 
eftablifh a communication’ between the infide of the balloon 
and the mercurial tub. (See fig. 2. Plate IT.) 

‘We then placed the diamond on the cup, where we left it, 
haying put it there by means ofa ribbon, which we drew from 
under it in an inflant, as foon as the balloon had been in- 
verted, and its neck immerfed in the mercury. The balloon 
in this pofition was made faft in a kind of collet, which 
tefted on the edges of an iron mortar that ferved as a hy- 
drargyro-pneumatic tub. We then exhaufted, by fuétion, a 
portion of the oxygen gas fufficient to make the mercury: 
rife to 12. centimetres above the orifice of the balloon. 

The diamond was the fame that had been already expofed 
to the action of the folar fire towards the end of the experi- 
ment of the preceding year, and which had loft only two 
deci-milligrammes, and confequently weighed 199: g milli- 
grammes (3°766 grains), or one carat wanting ~* 

On the 5th Fructidor laft year, at one in the Bicep okt 
we began to throw upon the diamond the focus of the large 
lens of the National Inftitute. . The thermometer, expofed to 
the fun under a bell-glafs, indicated 39°75: the mercury in 
the barometer ft0od at 75°89 centimetres, (28 inches 0-5 
lines.) The volume of air; inclofed by means of the mer- 
cury in the tub, brought to the preflure of 757°7 millime- 

* It is well known that the carat of the jewellers is only 205772 milli- 


grammes. 


VoL, V. Aa tres 


148 Experiments made at the Polytechnic School 


tres (28 inches), and to the mean temperature of 12°5 de- 
grees of the decimal thermometer, according to the experi- 
ments of.Cit. Pneier, and the tables of Cit. Prony*, was 
then found to be 11,470 cubic centimetres. 

Having taken the neceffary precautions to heat gradually 
the balloon, the point of the luminous cone being ,almoft in 
the centre, we were obliged to cover with a glafs plate the 
wooden fupporter, which was already on fire. The diamond 
firft exhibited a black point at the angle immediately ftruck 
by the fun. We afterwards faw it entirely black, and as it 
were charred: we diftinctly perceived, a moment after, bril- 
liant points in a ftate of ebullition, as it were, on the black 
ground. The folar rays, having been for a moment inter- 
cepted, it appeared tranfparently red. The fun becoming 
obfeured by a cloud, we faw it of a much purer white chan 
it had been at the commencement of the operation. 

The fun having emerged from the cloud, the furface of the 
diamond affumed the appearance of metallic fplendour: it 
was then fenfibly diminifhed, and there remained no more 
than a quarter, of a len¢thened form, without angles or per- 
ceptible edges, but ftill very white, and of a beautiful tranf- 
parency. We obferved a flight fiffure at the bottom of the 
pipe which fupported it, but without any feparation of the 
parts. I muft not forget, that at the commencement of the 
combuftion we thought we obferved a purpurefcent cone arifing 
from the fupport in the pencil of the folar rays; but this phe- 
nomenon was only an optical effet, which depended on the - 
pofition of the obferver. 

The whole apparatus was left j in the fame ftate, only de- 
fended by an inverted box placed over it, until the 7th, when 
we again began, at one hour twenty minutes, to prefent the 
diamond to the focus. We foon obferved the fame pheno- 
mena as on the 5th, the black furface, the brilliant points in 
ebullition, which vanifhed and re-appeared according to the 
intenfity of the focus: we faw alfo a brilliant metallid ap- 
pearance, or rather leaden-colour. This is the expreffion 
which the affiftants employed to charaéterife this phenome- 
non. At one hour forty minutes the diamond was entirely 


* Journal Polytechnique, Part IJ, p. 65. : 
confumed.' 


on the Combujtion of the Diamond. 179 


confumed. We at firft fufpected that there ftill remained a 
brilliant particle; but we foon judged that it was a vitrified 
point of the fupport, which was confirmed on in{peéting the 
pipe when drawn from the globe. The queftion now was 
to collec the products of the combuftion. No means feemed 
likely to be attended with more certainty than to introduce 
water of barytes into the apparatus, taking care to adhere, as 
nearly as poflible, to the proportions indicated for the fatu- 
ration of the carbonic acid, which we fuppofed mnft have 
been formed to prevent the uncertainty which the excefs of 
this re-agent might occafion in the refults. The whole ap- 
paratus being removed into the fhade, we began on the gth 
to draw out the pipe which ferved as a fupport, and obferved 
on it two flight fiffures occafioned by the contraction, and a 
{pot of four or five millimetres in diameter, the centre of 
which had a vitreous appearance, and its edges a reddifh hue. 
On examining it with a magnifying glafs, we obferved at the 
loweft point a fpace of two or three millimetres diameter, the 
furface of which was really vitrified, but of a tarnifhed and 
unequal colour. We diftinguifhed a particle of white glafs, 
pure and brilliant, formed into a globule fome fmaller por- 
tions of the fame nature, and two fmall globules of a vitreous 
fubftance, which had a greenifh red colour, 

On one fide we obferved on the edges feveral other very 
fmall globules interfperfed in a yellowifh ground, and on the 
oppofite a flight tinge of very bright red with very {mall red- 
difh points. A particle of white earthy matter was at firft 
taken for a fragment detached from the edges of the pipe, 
but it was found friable, and afcertained, by the ftain it left 
on gold, to be oxyd of mercury. This examination being 
finifhed, we introduced into the globe five meafures of fatu- 
rated water of barytes, each of 46°5 cubic centimetres. The 
liquor immediately aflumed a milky appearance, and there 
was a diminution in the volume of gas, which, calculated by 
means of the attached paper {cale, amounted nearly to 300 
cubic centimetres. Thus we might ftop here and confider 
the experiment as terminated, and by making fome allow- 
ance for the errors unavoidable in fuch manipulations, and , 
make the refult tally with the amount, determined before by 
the noble experiment of Lavoifier and La Place, of the re- 

Aaa {pective 


180 Experiments made at the Polytechnic School 


fpeétive quantities of carbon and oxygen which form the car- 


bonic acid. Mr. Tennant feems to have done the fame thing’ 


lately after the combuftion of the diamond by nitre. . But we 
fhould only have confirmed what was before known, or fup- 
pofed to be known. Our object was not only to obferve, with 
more attention, what took place during the aét of combuf- 
tion, but to afcertain,; as accurately as poffible, the nature 
and quantity of the product, and the reader will find that the 
Jabour undertaken on this fubjeCt has not been fruitlefs. 

The liquor was agitated in the globe to mix the white mat- 
ter which had been depofited. We drew out 4% meafures 
of the five we had introduced by making ufe of the fame in- 
verted bottle filled with mercury, and which we ratfed on the 
infide by means of an iron ftalk compofed of feveral pieces, 
which could be adjufted by ferews. (See fig, 6. Plate II.) 

We introduced into the balloon three new meatfures, each 
containing the fame quantity of diftilled water, which was 
fhaken in the infide to detach and colle€t what adhered to 
the fides. Thefe united liquors, being immediately filtered 
in an open filtre, left 192 centigrammes (36°142 grains) of 
garbonat of barytes dried in the heat of boiling water. 

It may be readily judged what was our aftontfhment when 
proceeding to examine the liquor, inftead of finding in it a 
flight excefs of uncombined barytes, we obferved that it 
changed neither the colour of turmeric nor that of logwood, 
and that, on the contrary, it acted on an infufion of turnfole 


as water charged with the carbonic acid. The prefence of 


this acid unequivocally manifefted itfelf, when we poured 
upon it a few drops more of barytes water, which immedi- 


ately rendered it turbid. It was neceflary to add even 4°65 


centimetres of this water to faturate and precipitate the re- 
maining acid gas. Being informed by this phenomenon that 
the produétion of the gas had been more confiderable than 
we expected, and that fome of it ftill remained mixed in the 
aériform fluid in the balloon, we took every meafure necef- 
fary to determine the quantity. This we. were luckily en- 
abled to do by the divifions which had been marked on the 
feales, the orifice of the globe having never been yet taken 

out of the mercury, 
When the barytes water was taken out, the apparent vo- 
lume 


' 
i 
» 
ae, 


on the Combujtion of the Diamond. ids 


Jume was found to be exa&ly 122 decilitres, the internal 
column of the mercury above the level of the tub was 47 
_ _ millimetres; the barometer being at 759°96 millimetres, 
_  {FruGidor 19, year VI.) the centegrade thermometer at 
21°25, the real volume, at a mean preflure and tempera- 
ture, was_112.426 decilitres, or 11242°66 cubic centimetres. 

I ftill invited M. Humboldt to co-operate with us in exa- 

mining the nature of this refiduum of gas. It was transferred 
in his prefence into a pneumatic tub prepared on purpole 
with diftilled water, and received into four large flafks. The 
trial was made by the fame in{truments. and with the fame 
. nitrous gas, which had férved for the oxygen gas before the 
combuftion, and confequently containing from o°og to 0°10 of 
azotic gas. The trials made on portions extracted from dif- 
ferent flafks varied from 37 to 34 in the quantity of the re- 
fiduum of gas, in a mixture of 100 parts of gas examined with . 
300 parts of nitrous gas. 
_ I thall not even take the mean term, I thall flop at the 
weakeft, which indicates four hundredth parts of carbonic 
acid gas, which, I think, I can affert to be rather below than 
above the truth; fince a portion of this fame gas, brought 
into contact with ammonia, under a receiver, experienced a 
diminution of 4°5, per cent. 

Let us now eftimate the carbonic acid gas which entered 
into the compofition of the 192 centigrammes of carbonat 
| of barytes. According to Pelletier, whole accuracy is well 

known in refearches of this kind, 160 of this earthy falt con- 
tain 22 of acid gas *, which gives 42°24 for 192; and as the 
cubic centimetre of gas weighs 1°847 milligrammes, it fol- 

_ lows that the 42°24 centigramimes reprefent 228-621 cubic 

centimetres, If we now add, on the one hand, the 449 cubic 

_ centimetres, found in the refiduum of the gas after combnf- 

_ tion, and which, as we {aw, formed the four hundredth parts; 

and deduét, on the other, the fame quantity from the acitform 

fluid in which the combuftion was effected, it refults, that in 

11470 cubic centimetres of oxygen gas contained in the bal-~ 
loon, there remained, after the combutftion, only 107933 that 
*y 677 were confumed; that thefe 677 cubic centimetres of 


+ Annales de Chimie, Vol. XXI, p, 135. 
oxygen | 


182 Experiments made at the Polytechnic Schoos 


oxygen gas, in the ratio of 1°3577 milligrammes cach, pro- 
duced, with the 1999 milligrammes of the dianiond, ¥117°96 
milligrammes of carbonic ate: 

Int the laft place; that, inftead of the proportions 0°28 of 
combuttible fubftance, and 0°72 of acidifying principle, ob- 
ferved in the combuftion of sani the proportion was, for 
the combutftion of the diamond, - 17°88 of carbon. 

82°12 of oxygen. 


100°090 


Though it was not poffible for me to doubt faéts deduced 
from calculation, I at firft hefitated to admit differences fo 
confiderable in the manner in which the fame combuftible 
united itfelf to oxygen in the quantities it could take up, and 
the products of its combuftion; in a word, a carbonaceous 
eombuftible more abundant in real combuftible matter than 
charcoal itfelf, and which at the fame time differed fo much 
from it m the degree of temperature neceflary to determine 
the action of its affinity. But I foon began to refleét, 1ft, 
Fhat this would not be the only inftance of the firft degree of 
the oxydation of an acidifiable bafe having been operated with 

great difficulty, while the acidification was afterwards com- 
pleted with the utmoft facility: 2d, That feveral fubftances 
of the fame kind prefented to us gio thefe two characters ; 
a greater abundance in real earbon, and greater refiftance to 
namin ation» ; fo that they naturally placed themfelves in an 
imtermediary rank between the diamond and charcoak. Thefe 
two confiderations, {lill ftrengthened by the fimilarity of the 
phenomena obferved during dig courfe of cur two experi- 
ments in the paflage of the diamond to the {tate of earbonie 
acid, appeared to me to throw a ray of Jight on this fubjec& 
hitherto fo obfeure. 

In regard to the firf confideration it will be fufficient for 
me to call to mind with what difficulty the commencement 
ef a compofition of azot and oxygen is formed by the, direc 
way, and the high degree of temperature which it requires, 
while nitrous gas cannot be in contact with oxygen without 
palling immediately to the acid ftate. Charcoal will then be 


to the carbonic acid what nitrous gas is to the nitric, and ” 


tha 


on ithe Combuftion of the Diamond. 183 


Hie diamond will be’ to charcoal what azot is to nitrous yas. 
There will, therefore, be no longer occafion of wonder that 
more oxygen is neceflary to that fubftance, which as yet has 
none of it, than to that which has already been united with the 
quantity neceflary for arriving at the fir{t point of faturation. 
The fecond confideration refs on facts no lefs conclufive. 
Plumbago is a carbonacecus combutftible, which does not burn 
but at a very high temperature, er in nitre in fufion; which 
produces by its combuttion carbonic acid; which, as well as 
the diamond, is more abundant in combuftible matter than 
carbon itfelf. We are indebted to the illuftrious Scheele for 
the fir obfervation of this fact. One part of carbon alca- 
lifes only five parts of nitre; ene part of plumbago can alca- — 
life ten. The operation performed im a retort on $0 centi- 
grammes of plumbago, gave him 357 cubic centimetres of 
carbonic acid gas*. This agreement will not be contefted 
by thofe who, having been witneffes of our experiment, fo 


- unanimoufly declared, that the furface of the diamond af- 


fumed inftantaneoufly a leaden colour. 

This mineral is not the only body which prefents thefe 
ftriking charatters of a fubftance almoft incombuftible, and 
yet very. abundant, in combuftible matter. I defcribed, fix- 
teen years ago, in the Memoirs of the Academy of Dijon, a 
foffil found in a mafs in the coal-pits of the Rive-de-Gier, 
which was fent to me under the name of incombu/izhle coal, 
and which I then confidered as real coal which had paffed 
to the {tate of plumbago. I charaéterifed it in that manner. 

Our brother Dolomieu has defcribed a foffil of the fame 
kind, which he calls.carbure of alumine, which is the an- 
thracolite of Werner. I had already fufpected that it was 


' neither the prefence of feur or five centiemes of alumine, nor 


that of a ftill fmaller quantity of iron, that rendered it in- 
combuttible, but the little advanced ftate of the oxydation of 
the carbon. I fubjeéted it to two experiments, by which this 
was fully confirmed. 

The object of the firft was to determine if the alumine 
prefent was in a flate of combination fufficiently intimate to 


* Mem, de Scheele, French edit. Vol. II. p.27 and 29. 
g refift 


¢ * 


- 


#34 Experiments made at the Polytechnic School 


tefift the action of pot- -ath by the humid way: 100 party 
put in digeftion in that folvent, left im it 4°6 of alumine. 

The fecond was, to afcertain whether this combuftible; 
which poffeffed fo little inflammability, had alfo the power 
to alcalife more nitre than carbon, confequently to take up 
more oxysen. Three fucceffive trials gave for a mean refult 
the alcalifation of 7°87 parts of nitre by one part of that mi- 
neral; and the fame coally matter, digefted for four or five 
days in oxygenated muriatic acid, burnt completely with 6°5 
of nitre. 

M. Klaproth, the celebrated chemift of Berlin, had brefots 
fubmitted to trials of the fame Kind a foffil deferibed by M. 
Widenmanin under tht name of incombuftible coal, and found 
that 100 parts left, after combuftion at a very flrong heat, 
only feven of a cineritious refiduum ; that treated in a cru 
cible with eight parts of nitre, and the mafs diffolved in water, 
acids occafioned no precipitate. Kirwan, in his experiments 
on coal, remarks, that that which he calls Kilkenny coal, and 
which has a metallic brilliancy, which does not burn but 
when carried to incandefcence, and which then comfumes 
flowly without emitting flame, can decompofe 9°6 of nitre. 

After this I do. not fee how there can remain any doubt’ 
that thefe fuppofed incombuftible fubftances are real oxydes 
of carbon, which, like coal or charcoal, have the property of 


conduéting the electric fluid; of cementing iron; of taking 


the oxygen from fome acidifiable bafes; but which are not 
at that degree of oxydation neceffary for exerciling this fepa- 
rating affinity at a weak temperature. 

I muft not omit this opportunity of making fome appli- 
cation of this principle, which may become ufeful to the arts. 
It has not yet. been fufficiently explained, why fome animal 
and vegetable matters produce carbon fo difficult to be inei- 
nerabade why charred pit-coal, known under the name of 
coke, or cinders, and which has been half burnt in the pre 
paration, is, however, fo powerful a combuftible; why peat, 
or turf, the weakeft of combullibles, acquires, by being pro-= 
perly charred, the property of welding large pieces of iron 
better than charcoal; and why, in the laft place, charcoal; 
when expofed to a very ftrong heat in’ veffels impenetrable 

to 


on the Combujtion of the Diamond. 185 


to air, becomes there, in a certain degree, incombuftible, as 
is proved in the experiment made by Mr. Tennant, which I 
have mentioned in the article Air in the Di@ionnaire de 
Chemie Encyclopedique, Vol. 1. p. 724. 

The anfwer to all thefe queftions may be found in the 
theory I have laid down: they are charcoals in the firft de- 
eree of oxydation. Thus fome of them have not yet acquired 
that which conftitutes charcoal properly fo called; others, 
after poffeffing all the qualities of vegetable and mineral car- 
bon, have returned to the firft degree by a real (debrulement) 
unburning of the remaining carbon; {fo that by lofing their 
imflammability they become capable of fixing a greater quan= 
tity of oxygen, and confequently of fetting at liberty a greater 
quantity of caloric when they find themfelves at a tempera- 
ture fufficiently high to determine and complete their acidi+ 
fication. 

Some practical confequences will doubtlefs hence be de- 
duced in regard to procefies for the reduCtion of ritetals; for the 
cementation of fteel, which it is probable takes up only oxyd 
of carbon, fince it is feparated from it in that ftate; for the 
incineration of the carbonaceous refiduums of our analyfes ; 
for the carbonifation of wood, pit-coal, and turf: in a word, 
we may perhaps thence conclude the poflibility of rendering 
ufeful thofe mafles of pit-coal, faid to be incombuttible, found 
at Rive-de-Gier, by mixing it with more inflammable mat- 
ters, to maintain the temperature which determines its com- 
buftion. Its pofition, texture, afd all its exterior characters 
announce, as already faid, that it confifts of beds of coal 
changed by a fubterranean fire; and this is confirmed by 
tradition, which preferved to that mountain, for three cen- 
turies, the name of the Mozntain of Fire. (Montagne de 
Feu.) We can now pronounce that it 1s coke too far ad- 
vanced, but fo much the more fufceptible of producing a 
great heat under favourable circumftances. 

i _ RECAPITULATION. 

I fhall here enumerate the confequences, or rather the 
fa&ts, which refult from the phenomena obferved in the two 

Vou.V. Bb ~ combui- 


186 Experiments made-at the Polytechnic School 


combuftions of the diamond by the folar fire, and the expe- 
timents which followed :— 

1. It is not only by the colour, weight, hardnefs, tranf- 
parency, and other fenfible characters, that the diamond 
differs from charcoal, as feems hitherto to have been be-. 
lieved ; 

Om Nav is it by the ftate alone of the aggregation of the 
matter that conftitutes diamond : 

3. Neither. is it gn account of the 20oth part of the cine- 
ritious refiduum left by carbon, or the {mall quantity of Bye 
drogen which it contains. 

4. It is more effentially by its chemical properties that it 
differs. 

5. The diamond is the pure combutftible fubftance of this 
genus, 

6. The produé& of its combuftion, or of its combination 
with oxygen to faturation, is carbonic acid without refidue. 

4. Carbon burns at a temperature eftimated at 188° of the 
centigrade thermometer ; the diamond does not inflame but at 
abact. 30 pyrometric meal which, according to Wedge- 
wood’s feale, makes a difference of 188 to 2765. 

8. Charcoal, when kindled, maintains of itfelf, in oxygen 
gas, the temperature neceflary for its combuftion, The com- 
buftion of the diamond ftops when you ceafe to maintain it 
by a furnace-heat, or the union of the folar rays. 

g. The diamond, for its complete combuftion, requires a 
much greater quantity of oxygen than charcoal does, and 
produces alfo more carbonic acid. One part of charcoal ab- 
forbs in this operation 2°527 of oxygen, and produces 3°575 
of carbonic acid. One of diamond abforbs a little more than 
four of oxygen, and really produces five of carbonic acid. 

10. There are fub{tances which are in a ftate of interme- 
diary compofition between the diamond and charcoal. Thefe 
are plumbago, or native carburet of iron ; incombuitible fofiil 
coal; the carburet of alumine of Dolomicu ; the anthracolite 
of Ww erner; the black matter united to iron in the ftate of 
caft iron and fteel ; carbonaceous refiduums difficult to be 
incinerated ; and carbon itfelf unburnt, (d/drulé,) by the 
action of a ftrong heat without the contact of air. . 

9 11. Thefe 


on the Combuftion of the Diamond. PEAR | 


11. Thefe fubftances mixed, or weakly combined with 
three or four hundredths of their weight of iron, or alumine, 
give by their combuttion carbonic acid, like charcoal and the 
diamond. é 

They approach to carbon by their colour, their lightnefs, 
their opacity; by their ferving, like it, 1o decompofe water, 
to cement iron, to deoxydate metals, to deoxygenate ful- 
phur, phofphorus, and arfentc; and by conduéting, like it, 
‘the eleGtric fluid. They approach the diamond by contain- 
ing more combuftible matter than charcoal; by abforbing 
alfo more oxygen, and producing more carbonic acid; by 
decompofing more nitrous acid; by burning only at a much 
higher, temperature, even in nitre in fufion; and by their 
combuftion being ftopped when this temperature is lowered. 
They feem to differ from each other by the property of pro- 
ducing with zine galvanic irritation, as well as filver does : 
which can be effected neither by the diamond nor charcoal. 

12. Thus the diamond is pure carbon, the pure acidifi- 
able bafe of the carbonic acid. Its combuftion is effected in 
three periods, which require three different temperatures. At 
the firft, which is the higheft, the diamond affumes a black 
leaden colour. It is an oxydation in the firft degree, the ftate 
of plumbago and anthracolite. At the fecond temperature, 
which may be eftimated at 18 or 20 pyrometric degrees, 
there is a fecond flow and fucceflive combination of oxygen. 
It is a progrefs of oxydation which conftitutes the habitual 
ftate of charcoal, or rather that in which it is found after 
the action of a flrong heat in clofe veffels has difengaged a 
part of its oxygen. 

Thus plumbago is an oxyd of the firft degree, charcoal an 
oxyd in the fecond, and the carbonic acid the produét of the 
complete oxygenation of the carbon. 

Suppofing, then, that we operate with fufficient precifion 
to take away from the furface of the diamond the black mat- 
ter in proportion as it is formed, by fuddenly withdrawing 
from it each time the action of the folar fire, we fhould doubt- 
lefs be able to convert it into charcoal, or at leaft plumbago, 
if the too rapid paffage of the laft degree of oxydation to oxy- 
genation did not prevent us from furprifing it in that ftate. 

; Bb2 13. In 


388 Objeétions to the Mitchillian 


13. In the laft place, feveral confequences, of importance 
to chemiftry and the arts, arife from thefe principles, 

After this conclufion it will be afked, no doubt, how it 
happens that the fimple matter, pure carbon, the diamond, 
as fo rare while its compounds in different ftates are fo abun- 
dantly diffufed? To put an end to the aftonithment of thofe 
who might entertain any miftruft, I thall obferve, that alu- 
minous earth is alfo one of the moft common matters, and 
that adamantine fpar, as rare as the diamond, is however 
only alumine; that iron every where exifts, under all forms, 
except in the ftate of purity; the exiftence of native iron is ftill 
doubtful. The wonder exifts only in the oppofition of faéts 
to gur opinions, and will difappear in proportion as we dif. 
cover, and appropriate to ourfelves, the means employed by 
nature in producing the fame effects, 

Thofe who have never turned their attention to the hi 
fical fciences, to eftimate at leaft their influence on public 


- _ felicity, are difpofed to treat as vain curiofity labours which 


are not immediately directed towards a near objet of new 
enjoyment. What would have been their aftonifhment had 
they been told, that refearches on the nature of the diamond 
would one day produce truths which might give rife to 
happy changes in the practice of the moft familiar arts; in 
the preparation, and in the employment of the coarfeft com- 
buftibles! Such, however, are the confequences that may 
arife from the beft known properties of the effential principle 
carbon in its different ftates. 


XI. A Letter to the Editor, containing fome Objeétions to the 
Mitchiluian Theory of Peftilential Fluids. 


STR, 


OBSERVE, in the 15th Numher of your ufeful Maga+ 
zine, a communication from Dr. Mitchill, of New-York, 
fhewing the utility of conftructing the witht and paving 
the ftreets of cities, with calcareous in preference to JS liceous 
and argillaceous materials. This communication is con- 
tained in a letter from Mr, Da Cofta to the Dodtor, in which 

it 


Theory of Peftilential Fluids. , i89 
it is obferved, that although the city of Lifbon is one of the 
filthieft in Europe, and the moft infefted with putrid effluvia, 
yet that it neverthelefs is remarkable for its falubrity., This 
is attributed by Mr. Da Cofta to the calcareous materials, 
of which the buildings and pavements are conflructed, ab- 
forbing and neutralifing the feptic fluids, the caufe, accord- 
ing to Dr. Mitchill’s theory, of all contagion. 

In reply to this I would obferve, that from the author’s 
own account it is evident that the calcareous earth in the 
city of Lifbon does mot deltroy the putrid exhalations in any 
fenfible degree, and therefore cannot prevent any diforders 
to which they may give rife. The houfes, he obferves, are 
very offenfive, from the privies, and from inattention to clean- 
linefs. The mouths of the fewers go to. the wharves, and are 
bare at low water. The fluid which comes from thefe con- 
tains fo many infectious matters that its /lrong putrid fmell 
can fearcely be endured! It is plain, therefore, that the pu- 
trid exhalations are not deftroyed, or, at Jeaft, that they are 
fo quickly generated as to annoy the olfactory fenfe in an 
intolerable degree. The bodies of the inhabitants are con- 
tantly immerfed in putrid exhalations, yet contagion is not 
produced. The inference is, that putrid exhalations are not 
its immediate caufe. Contagion arifes where no putrefac- 
tion is going on, at leaft in any degree perceptible to the 
fenfes; as when a number of perfons are crowded together 
in jails, and even in the houfes of the poor in the winter 
feafon, without fufficient ventilation. On the other hand, 
putrefa&tion may be prefent, in a very high degree, without 
giving birth to contagion, as may be obterved in flaughter- 
houfes, cat-gut manufactories, &e. 

But, is it proved fufficiently that calcareous matters do 
abforb and neutralife feptic exhalations? Mr, Da Cofta re- 
marks, that he has obferved, two or three times, in Lifbon, 
dead animals upon the ruins of houfes, and of courfe fur- 
rounded by calcareous earth, in a ftate of deficcation ;. and, 
at the fame time, two or three fathoms diftant, another ani- 
mal dead too, and lying upon another kind of foil, in a ftate 
of complete putrefaction. I do not prefume to. queftion the 
truth of this, fince it was a matter obvious to the fenfes: but 

I deny 


¥90 Defcription of an Improved Air-Furnace. 

¥ deny the generality of the fa& equally from obfervation. 
I fufpended a piece of flefh, in a proper veffel, over a layer 
of chalk, and at the fame time laid chalk, in fmall pieces, on 
gauze, a few inches above the flefh: but I did not obferve 

that putrefa@ion was more backward than in other eireum- 
ftances, or that putrid exhalations were lefs extenfively dif- 
fufed around. That quickline deftroys putrefaction, is no 
proof of the opinion here advanced, fince this can be ac- 
counted for on other principles. 

If fevers Abound on the oppofite fide of the Tagus, whilft 
the city of Lifbon is free from them, there are probably other 
eaufes to which this may be afcribed, fuch as a marfhy foil, 
&c. Whether any thing of this fort exifts, the account here 
given by Mr. Da Cofta does not enable us to judge. 

It is the tendency of Dr. Mitchill’s theory to overturn fet- 
tled opinions, and to caufe us to abandon’ praétices, which 
have been generally employed, and much rehed on, for the 
deflruGtion of contagious matter. It is of great importance, 
therefore, that it fhould be well founded, left we be induced 
to lay afide means that are efficacious on grounds not fufh- 
ciently eftablifhed. Whatever becomes of Dr. Mitchill’s 
hypothefis, it appears to me to receive no fupport from the 
facts and arguments of the paper in queftion, although it is 


confidered by him as affording a ftrong confirmation of its 


truth. 
Withing every fuccefs to your valuable publication, I re- 
main, oe yours, &c. 


H. CLUTTERBUCK, 
Walbrook, O&. 21, 1799. 


KIL. Defcription of Mr. Howarn’s Improved Air- Furnace, 


i HE difficulty of obtaining a degree of heat fufficiently 
intenle for many operations in chemiftry, has been felt and 


lamented by every one engaged in fach purfuits; and, not- 


withftanding the refearches and -numberlefs experiments 
made profefiedly for that purpofe by the greateft men, the 
beft conftruction of an air-furnace is {ti]] a problem; in- 

deed, 


es 


Defcription of an Improved Air- Furnace. 19% 
deed, the rules laid down by thofe who have written on this 
fubjeét, differ fo widely from each other, that we muft fup- 
pofe a great number of circumftances, hitherto overlooked, 
enter into the conftru&tion of a good furnace. Having ob- 
ferved effects produced in that of Mr. Edward Howard, of 
Doughty-fireet, which we have feldom, if ever, feen equalled 
in any other furnace, we thought we could not better oblige 
our chemical readers than by giving a defcription of it. The 
difference in the prefent eaeaaGiied of Wedgewood’s pyro- 
meter pieces, from that ufed by him when he firft invented 
his inftrument, makes it impracticable (unlefs the {eale was 
alfo altered) to meafure correétly the degree of heat obtained ; 
it muft however be at leaft = 160°, and 1s fufficient to run 
down the beft Heffian crucibles. The moft ftriking devia- 
tion from the common confiruétion is in the lower part of . 
the chimney, or flue, being fmaller than the upper, and 
the greater depth of the afh-pit. Mr. Howard thinks that 
fomething depends on the direction of the horizontal fun- 
nel, which in this cafe opens to the north. Ii any of our 
readers fhould confiruét a furnace on this plan, we fhould be 
glad to be informed of the coincidence of effect *. 

Fig. 1. (Plate [V.) A, the cavity or body of the furnace, 

9 inches {quare and 1 foot 7 inches deep to the bars. B, the 
_ath-pit, 1 foot 2 inches, by g inches broad, and 2 feet 8 inches 
deep below the bars: this afh-pit opens to the external air by 
an horizontal funnel C, 6 feet long,  pafling under the floor 
of the laboratory: this not only furnithes a fupply of denfer 
air, but prevents the unpleafant effects of the cold draught 
on the legs and feet of the operator, which happens when the, 
ath- -pit opens into the laboratory. The external opening of 
this funnel is about 2 feet {quare, w vhich gradually contracts 
to the afh-pit in the manner fhewn in the plate. D, the 
aperture of the horizontal flue, 7 inches wide by 2! deep, 
contracting in width to 43 inches, where it enters the ver- 
tical flue or chimney, which is 44 inches. {quare, of which 
width it continues to the height of 7 feet, and is then en- 
larged to 5 inches fquare; which dimenfions it shine cia to 


* Dr. Pearfon's furnace, which is a very powerful one, agrees in fome 
parts of its conftruétion with Mr. Howard's 


the 


192 Travels through Egypt and Syria. 
the top of the brick-work, being 161 feet from E. The 
chimney finifhes by an iron pipe about 3 feet long. 

Fig. 2, F, thews the plan of the body of the furnace g inches 
thick, the top courfe of bricks being bound together in the 
ufual manner by a ftrong iron hoop G. H is an horizontal 
fe€tion of the chimney and flues*. When only a moderate 
decree of heat is wanted, the horizontal draught-hole C can 
be clofed by a fliding door or regifter, and an opening made 
into the afh-pit, direétly under the bars, by removing the 
ftone ftopper I. (Fig. 1 and 2.) This alfo is ufeful for oc- 
cafionally clearing the bars from feoria, or entirely removing 
them, in order fuddenly to put out the fire. The whole of 
the furnace and chimney is built of Windfor bricks. 


XI. An Account of Mr. Brown’s Travels through . 
Egypt and Syria, &c. 
[Concluded from Page 76. ] 


Ma. BROWN retired a fecond time to Cobbé, with > 
little hopes of ever leaving the country. Of the property, 
which the king’s agents had purchafed on bis arrival, no 
part of the price had yet been paid. He had been infulted 
with the mockery of juftice, yet obliged to thank his oppref- 
fors for the compenfation which their corruption. and malig 
nity alone had rendered incomplete. \ 

He had not omitted to renew to the Melek Mufa the re- 
queft which had been previoufly made to Mifellim and Ibra- 
him. He explained to him, in the leaft exceptionable man-' 
ner, his intention of coming to Cobbé ; completely did away 
all the fufpicions which his enemies had at firit excited ; and 
concluded with defirine permiffion to go to Sennaar, or to 
accompany the firft /e/atea (an armed expedition for the pur- 
pofe of acquiring flaves,) to the fouth or fouth-weft; or to 
have a fafe conduct, and one of the Sultan’s flaves, to dc- 
company him to Bergoo, (the firft Mahometan kingdom on 

the weft.) By the firft route he hoped to have reached Abyf- 
finia, or, if that had been impracticable, to have gone through 
Nubia to Egypt, or by Suakim to the Red Sea, and thence 


* The chimney is detached. about an inch from the wall behind all the 


way to the top. 
to 


through Egypt and Syria. 193 


to Mocha or Jidda. By the fecond he was almoft certain of 
fetUling fome important points relative to the White River, 
poliibly of tracing it to its fource. And by the third, either 
of paffing directly weft, and tracing the courfe of the Niger, 
or.of penetrating through Bornon and Fezzan to Tripoli. 

To the firft propofal he anfwered, in a manner which gave 
Mr. Brown reafon to doubt his fincerity, that the road to 
Sennaar was unpaflable, the Sultan being then mafter of 
He one half of Kordofan: that the natives of all that part 
of ‘it which remained eaiebdaeH were his implacable foes, 
and would infallibly deftroy any perfon who came from Dar- 
Fir: that he thought, however, if Mr. Brown waited an- 
other year, that route might poffibly be more feeure; and in 
cafe it fhould, he would uife all his efforts to obtain the Sul- 
tan’s permiffion for his departure.—Of the Se/atea he faid, that 
our traveller wou'd only encounter certain death by attempt- 
ing it, as, between the jealoufy of thofe who accompanied 
him, and the aétual hoftility of the country, there would be 
no hope of efcaping. Mr. Brown hinted, that the Sultan 
might give him a few attendants, whom he was very ready 
to pay, and an order to enable him to pafs unmolefted as 
nis phyfician in fearch of herbs. He replied, that he would 
propofe fuch a meafure, but he did not expeét it would re- 
ceive the Sultan’s approbation.—To the third propofal he an- 
fwered, that he had no hope of Mr. Brown’s fucceeding, and 
concluded with ftrongly recommending to him to feize the 
firft opportunity of returning to Egypt; but he affured him, 
if he could accomplifh any of the meafures he fo much 
wifhed, he would not fail to inform him and to afford him 
the neceffary aid’ Such was the ftate of affairs when Mr. 
Brown returned to Cobbé, dejeéted, and with little expeéta- 
tion of realifing even his leaft fanguine, hopes. ‘ Not more 
than fix weeks after this dokverfation had taken place, he was 
fent for to attend the Melek, who was confined by an old 
‘diforder in his tangs. He found him yet fenfible; but his 
‘eyes were fixed, “and extremities incapable of motion. Th 
five hours after, he expired. Thus were blafted our traveller’s 
‘returning: hopes of fuccefs; for'no mediator now remained 
‘between him end’ the monarch, ‘and no longer was there 

PeVOL, Vv, Ce near 


194 An Account of Mr. Brown’s Travels 


near the court a man even of feeming liberality and good 
jenfe, to whom his projects might be fafely opened. 

During the fummer of 1794, five men who had exercifed 
confiderable authority in fome of the provinces, were brought 
to El Father’as prifoners ; it was faid that they had been de- 
tected in a treafonable correfpondence with the hoftile leader, 
Hafthem, in Kordofan. They did not undergo any form of 
trial; but as the Sultan chofe to give credit to the depofitions 
made againft them, his command was iffued for their execu- 
tion. Three of them were yery young men, the youngeft not 
appearing to be more than feventeen years of age. A little 
after noon they were brought, chained and fettered, into the — 
market-place, before one of the entrances of the palace, ef- 
corted by a few of the royal flaves armed with fpears. Se- 
veral of the Meleks, by the monarch’s exprefs order, were 
prefent, to witnels, as he termed it, what they might expeét 
to fuffer if they failed in their fidelity. The executioner al- 
lowed them time only to utter a fhort prayer, when he plunged 
his knife into the neck of the oldeft, exaétly in the fame 
manner as they kill a fheep. The operation, too, is marked 
by the fame term, dhebbah. He fell, and ftruggled for fome 
time, The reft fuffered in their turn. The three laft were 
much agitated, and the youngeft wept. The two firft had 
borne their fate with becoming firmnefs. The crowd that 
had affembled had fearcely fatiated itfelf with the fpectacle 
of their convulfive motions while proftrate in the duft, when 
the flaves of the executioner coolly brought a fmall block of 
wood and began mangling their feet with an axe. Having 
cut off their feet, they carried away the fetters which had been 
worn by the criminals, though of Jittle value, and left the 
bodies where they-were. Private humanity, and not public 
order, afforded them fepulture. 

Near the end of the year 1795 a body of troops was muf- 
tered and reviewed, intended to replace thofe who had died 
of the fmall-pox in Kordofan, which, it was faid, amounted 
to more than half the army. The fpoils which had been 
taken from Hafhem were alfo oftentatioufly difplayed on this 
occafion. They confifted of eighty flaves, male and female, 
but the greater proportion of the latter, many of whom were 

exceedingly 


. 


‘ 


through Egypt and Syria. 195 


exceedingly beautiful, nor the lefs intcrefting, that, though 
the change in their fituation could. not be very important, 
their countenances were marked with défpondency. To 
thefe fucceeded five hundred oxen and two hundred large 

_ eamels; the whole proceflion was clofed by eighty horfes, 
and many articles of lefs value borne by flaves. Shouts rent 
the air of, Long live El Sultan Abd-el- rachman el rafhid ! 
May God render him always victorious ! 

A fhort time after, Mr. Brown caufed a petition to be 
drawn up, which was prefented by Ali-el-Chatib to the Sul- 
tan, in which he ftated his fufferings, requefted payment of 
what yet remained due to him, and permiflion to proceed on 
his journey to Kordofan. Though the perfon who prefented 
it was a man of confiderable weight, no anfwer was given. 
He therefore followed it up by a vifit in perfon, which he 
had refolved fhould be his laft. His arrival was no fooner 
known than he was directed to attend fome fick perfon, as 
he had feveral times done before. This he pofftively refufed, 
and it was many days before he could be admitted at court. 
On the 11th of December 1795, however, he accompanied 
the Chatib to the monarch’s prefence, and briefly {tated what 
he came to requeft; which the former feconded, though not 
with the zeal Mr. Brown wifhed, To his demand of permif- 

fion to travel, no anfwer was returned. But the generous 
and hofpitable monarch, who had received from him the 
value of 750 piaflres in goods, though his claim was well 
fupported, gave him only twenty meagre oxen, in value about 
120. piattres ! The ftate of his purfe would not permit him 
to refufe even this mean fupply; and he bade adieu to El 
Father, as he hoped, for ever. 

Having applied the value of the oxen to prepapations for 
his journey to Egypt, the report of the caravan’s departure 
growing daily ftronger, he loft no time in joining the Chabir, 
who was then encamped at Le Haimer, (3d March 1796,) a 
fmall village about three days journey north of Cobbé, where 
there was a tolerable fupply of wah ss but no other requifite 
for living. 
fe(Mr. Brown arrived at Le Haimer about a month before 
Ramadan; and it was not till the fixth day of E] Hedge, the 

Cc fecond 


196 Tenth Communication from Dr. Thornton. 


fecond month after that faft, that they a@tually commenced 
their journey to Egypt. In the mean time, baving pitched 
a tent under a great tree, where they were fheltered from the 
rays of the fun, he fed on polenta (as-eid’) and water with 
the camel-drivers. He had collected eight camels for the 
journey, but the beft of them was ftolen. while grazing ;~an- 
other died; and to fupply his place he was obliged to feek 
one on credit, for his whole exchangeable property at that 
time amounted only to eight piafires. 

The journey, once commenced, was continued with little 
remarkable except violent heat.. They returned by the only 
caravan route, Bir el Malah, Leghea, Sclime, Sheb, and El- 
aah, Their provifions were indifferent, and in fmall quan- 
tity. The camel-drivers regaled themfelyes with the fleth of 
thefe animals when they chanced to be difabled on the road. 
When they arrived at Beiris, they were met by a Cafhef, who 
* welcomed the Jelabs with an exhibition of fire-works. On 
this occafionsp is cuftomary to treat the chief merchants with 
coffee, and to prefent to each a ben./b of coarfe cloth, worth 
about a guinea; but he expects in return a flave from each, 
worth about ten guineas.» When Mr. Brown arrived at 
Affidt, he had been four months without eating animal food; 
and the hard living, heat, and fatigue, had brought on a di- 
arrhcea, by which he was much weakened; but before he left 
Affiat, where he paffed twenty days, it was much abated. 

After fome ftay in Egypt Mr. Brown embarked for Syria 
“on the 19th of January 1797 5 and having vifited Jerufalem, 
Damatcus, Aleppo, and: various other places, proceeded to 
Conftantinople ; from which he returned to England by 
Vienna, Drefden, Leipfic, and Hamburgh. He arrived! i in 
London on the 16th of September 1798, after an abfence 
of nearly feven years. 


XIV. Tenth Communication from Dr. THORNTON, Phy. 
feian to the General Difpenfary, &c. &c. &e. action to 
Pneumatic Medicine, 


One of the moft dreadful of human affli@ions is that 
where water opprefles the brain; and there are no hopes of 
\ any 


, 


Intelligence and Mifcellaneous driicle i. 197 


any medicine getting to that part, except what firft can enter 
the blood. Mercury has been fuccefsfully employed; but it 
produces fo great a derangement of the general health, that 
a fubftitute is certainly advifable. Can the abforbents of the 
brain be equally excited by vital air? 

Lydia Johnfon, zt. 13, living at No. 5, Hufband- 
fireet, after a putrid fever became perfectly blind, and 
had frequent fits, evidently arifing from oppreffion of the 
brain. Various means had been employed without the leaft 
advantage. I referred her to Meffrs. Wathen and Phipps, 
that they might fee the cafe. Under the inhalation of vital 
air, with the aid of bark’ and fteel, the fits foon gave way; 
and afterward, finding the air produced no mifchief, I in- 
creafed the quantity one day.to twelve quarts, mixed with 
three times that quantity of atmofpheric, and almoft imme- 
diately after the inhalation fhe had a dawning of fight, and 
going home fhe did nothing but cry out, Mama, mama! I 
fee now every thing. The cure has remained permanent 
above a year, and I faw her the other day in perfect health 
and fpirits, 


INTELLIGENCE, 


AND . 


MISCELLANEOUS ARTICLES. 


ROYAL SOCIETY OF LONDON. 


In the courfe of the prefent month (November) the Second 
‘Part of the TranfaGtions for the year 1799 was delivered to 
the Members. The contents are:—An account. of the dif- 
fection of an hermaphrodite dog: to which are prefixed, fome 
obfervations on hermaphrodites in general. By Everard Home, 
Efq. F.R.S.—An enquiry concerning the weight afcribed 
to heat. By Benjamin Count Rumford, F.R.S.M.R.1. A. &e. 
—An account of fome experiments on the fecundation of ve- 


getables: ina letter from Thomas Andrew Knight, Elq. to 
the 
\ 


198 _ Royal Society of London. 
the Right Hon. Sir Jofeph Banks, K.B. P.R.S.—Obferva- 


tions on the different fpecies of Afiatic elephants, and their. 


mode of dentition. By John Corfe, Efq. Communicated 
by the Right Hon. Sir Jofeph Banks, Bart. K.B. P.R.S.— 
Some abiervations on the ftruéture of the teeth of gramini- 
vorous quadrupeds, particularly thofe of the pipes and fus 
fEthiopicus. By Everard Home, Efq. F.R.S.—Experiments 
to determine the quantity of tanning principle and gallic acid 
contained in the bark of various trees. By George Biggin, 
Efq. Communicated by the Right Hon. Sir Jofeph Banks, 
K.B.P.R.S.—Effay on the refolution of Algebraic equations ; 
attempting to diftinguifh particularly the real principle of 
every method, and the true caufes of the limitations ta 
which it is fubje&t.- By Griffin Wilfon, Efq. Communi- 
cated by Edward Whitaker Gray, M.D. Sec. R.S.—On 
different forts of lime ufed in agriculture. By Smithfon 
Tennant, Efq. F.R.S.—Experiments and obfervations on 
fhell and bone. By Charles Hatchett, Efq. F.R.S.—A ca- 
talogue of Oriental manufcripts, prefented to the Royal So- 
ciety by Sir William and Lady Jones. By Charles Wilkins, 
Efq. F.R.S.—Prefents received from rene 1798 to June 
4799- 

On the 7th inftant the Society met for the firft time fince 
the long vacation, when the Croonian Leéture on mufcular 
motion, by Everard Home, Efq. was read. The fubject was 
on the conftruction of the membrana typani, At the fame 
fitting a pi€ture, by Mr. Brown, of the late Mr. Smeaton, 


civil engineer, was prefented to the Saciety by Alexander 


Aubert, Efq.* 

Nov. 14. The conclufion * the Croonian Lecture was 
yead, and a letter addreffed to Count Bruhl on the orbit of 
the comet feen in Auguft. 

Noy. 21. A paper by Dr, Herfchel on the power of pene+ 
trating into fpace by means of telefcopes. . This, the Doétor 
remarks, is connected with fomething different from their 
magnifying power. The extreme fenfibility of the optie 


* The meeting-room is hung round with portraits of deceafed meme 
pers; that of Sir Lfaac Newton being placed over the prefident’s chair. 
nerve 


Meteors. 19g 


nerve is fach as to require twenty minutes reft, on coming 
from the light, before (when his head is covered with a black 
hood) he is able to difcern fmail telefcopic ftars: an equal 
time is neceflary aftera ftar of the fecond or third magnitude 
pales the field of the telefcope——The paper was not gone 
through at this fitting. 


METEORS. 


Fiery Meteors have been more than ufually common of 
late. 

On Saturday night, the 2d of November, at half paft tem 
o'clock, a meteor, or ball of fire, paffed through the air im- 
mediately over the town of Pocklington, accompanied with 
a moft beautiful train of fire refembling the tail of a rocket, 
and appearing to be about 15 yards in length. The direction 
was from the north-eaft to the fouth or fouth-weft, and con- 
tinued vifible for about half a minute. 

Qn Tuefday morning the 12th of November, about fix 
o'clock, a meteor, or ball of fire, accompanied with a beau- 
tiful train, was obferved in different parts of Staffordfhire. It 
was preceded by feveral flafhes of vivid lightning. 

' The fame, or a fimilar meteor, was feen at the fame time 
in Yorkthire. The following is a defeription of it, as feen at 
Hull and the neighbourhood :—On the morning of the 12th 
of November, between the hours of five and fix, the heavens 
exhibited an awfully grand appearance. The fetting meon 
became partially ob{cured by dark cloudy {pots or {ftreaks : 
in oppofition to her was feen a lunar rainbow of the moft 
beautifully varied colours; after which, the middle region of 
the air was illuminated by meteors croffing each other in 
different dire€tions, and leaving behind them long {parkling 
trains, which were vifible for two or three minutes after thefe 
himinous bodies had difappeared; one of thefe meteors, more 
brilliant than the reft, illuminated the whole firmament, and, 
by its apparent approximation to the earth, created fome 
alarm. The thermometer was that morning at 50 degrees, 
The air, which the preceding night was cold and frofty, 
etonte remarkably clofe and warm, and produced on the 
walls 


200 Converfion of Iron into Steel. 


walls and furniture in Houles a an unufual danrpnefs and hu- 
midity. 


CONVERSION OF IRON INTO STEEL. 
In our Saft we noticed that Mr. Muthet, in varying the 
experiments fuggefted by C. Clouet’s procefs for the conver- 
fion of iron into fteel by cementation with carbonat of lime, 


had found that when lime, previoufly deprived of its car- 


bonic acid, was wled with the iron, the refult was, notwith- 
ftanding, caft fteel; and that, therefore, he found himfelf 
obliged to reje& the idea of the carbon neceflary to the con- 
verfion of iron into fteel, having been furnithed by the de- 
compofition of carbonic acid. 

We alfo in our laft Number laid before our readers C, 
Guyton’s report of the converfion of iron into caft fteel by 
means of the diamond, which is generally held to be pure 


carbon, and which, having difappeared in the procefs, was. 


therefore believed to have entered into chemical union with 
the iron by the affinity exejted between them by means of 
an high temperature. 

From the tenor of the letter from Mr. Muihet, which fur- 
nifhed us with matter for the notice firlt above referred to, 
we were led to fufpeét that, however probable it might be 
that in the cafe Jaft mentioned the carbon, which went to 
fteelify the iron, was furnifhed by the diamond; yet, as Mr. 
Mnifhet’s experiments went to thew that carbon could find its 
way from the ignited gas of the furnace to the iron, through 
materials which, on firft view, one would-hardly think per- 
vious to fuch a principle, it was certainly poflible that the 


French chemifts might be miflaken, and that the carbon, . 


which converted the iron, might not after all have been 
furnifhed by the diamond. 

Since, then, we correfponded with Mr. Mufhet on the ful 
je&t, and propofed that the experiment made at the Poly- 
technic School fhould be repeated, only keeping out the dia- 
mond, As the idea arofe from, and might indeed be faid to 
be embraced in, the fa&s prefented by Mr. Muthet; and as 
the procefs coincided fo nearly with others which he had 
communicated as executed and in train, we knew no perfon 


q fo 


Converfion of Iron into Steel. 201 


fo likely to do it complete juftice, or fo well qualified by great 
experience to cuard againft error. In this we have not been 
deceived. Mr. Mufhet, whofe zeal in every thing that con- 
cerns the improvement of the Britifh iron manufactory en- 
titles him to the gratitude of his country, has proved, by fe- 
veral conclufive experiments, that the French chemifts would 
have had fteel from their experiment even if no diamond had 
been employed in it. We {hall not detain our readers longer, 
but content ourfelves with laying before them 


An Account of the Experiments made by Mr. Mufbet with a 
view to prove whether the Experiment made at the Poly- 
technic School re/pecting the Converfion of Iron, into Seel by 


means of the Diamond is conclufive. 


I. © I introduced into a crucible fome pieces of foft mal- 
Jeable iron weighing 1250 grains. A larger crucible was 
next taken, half filled with fand pounded from the fire- 
ftone of which the blaft-furnace hearths at Clyde are made. 
The fmall crucible containing the iron was inverted upon the 
furface of the fand in the fecond crucible,.and forced fo far 
‘into it as to bring the iron and fand nearly into contact. The 
fpace betwixt the exterior furface of the fmall crucible, and 
the interior furface of the large one, was completely filled 
with the fame fand; the eeee of the inverted one alfo 
received half an inch of fand. This quite filled the outer 
crucible, and made it have the appearance of being entzrely 
filled with fand: a well fitted fire-clay cover fealed the whole. 
After a violent heat for 65 minutes the crucibles were with- 
drawn from the furnace: when cool, I found a flight crack 
in the exterior one; the fand however remained entire, and 
firmly cemented ‘bgmethier: though not vitrified, forming a 
thick porous lute {urrounding the fall crutible. Upon re- 
moving the fand, and examining the interior veffel, I found 
the pieces of iron fufed into one folid mafs, which proved foft 
fteel. The mafs of fand, which occupied the mouth of the in- 
verted pot, contained feveral detached globules of fteel; thefe, 
during the intenfity of the heat, and the extreme divifion of 

the fluid, had penetrated the fand, and one of them had ac- 
tually reached the bottom of the outer crucible. Thefe maffes 

Vou. V. Dd had 


202% Converfion of Iron into Steel. 


had in their defcent conveyed a blackifh-blue celour to the 
fand, and the fufion of the whole had glazed the bottom and 
fides of the inverted crucible, unoccupied by the fand, with 
the fame colour. The principle button, and fmall pieces, 
weighed 1229 grains: lof, 21 grains, =, of the original 
weight of the iron. 

“¢ The quality of this fteel was s uncommonly red- sbi and 
it was with difficulty it would take a form under the hammer, 
When cold it was much tougher than good fteel is ever found 
to be, and diftended in this ftate afionifhingly under the ham- 
mer. The fufion, however, had been moft complete; every 
part of the refult poffeffed a cryftallifed furface more or lefs 
accurate. Upon the whole, the quality of this fleel is, I 
think, fimilar to fome defcribed lately by C. Clouet. Its 
uncommon fortnefs, while it poffefled not the property of 
drawing into fhape with a fmooth uncracked furface, led me 
_ to conceive that the fufion was urged too {peedily, and before 
the fufficient quantity of carbon had been taken up which 
conftitutes good fteel. This induced me to repeat the experi- 
ment in the following manner :— 

II. * Having finerpete in an eer es three 
crucibles, made from Sturbridge clay, of various fizes; into 
the fmallcft one I put five pieces of malleable iron weighing 
1875 grains; upon the top of which I wedged a high-baked 
cover of fire-clay: upon the top of this cover, and to a level 

-with the edges of the crucible, I introduced infufible fand. 
This operation was performed upon a plate of red-hot iron, 
Jeft the fudden. contact of the cold air fhould endanger the 
foundnefs of the pots. The fmall crucible was next intro- 
duced into the fecond fize, and a cover fitted over the two. 
Lafily, this double crucible was placed into one fo much 
larger as to admit of a ftratum of fand, nearly half an 
inch thick, in fuch a manner as to infulate the former moft 
completely. This operation finifhed by covering the outfide 
crucible with a large fire-clay cover. My reafon for leaving 


the vacant fpace betwixt the two innermoft crucibles not 


filled up was, to guard againft any error in the refult, which 
might probably be occafioned by the aétion of the interior 
fire-clay caver, and the fand, in their refpective degrees of 

9 : fhrinkage 


Gonverfion of Iron into Steel. 204 
fhrinkace and expanfion. The whole was expofed to 4 mo- 
derate white heat for nearly. an hour, and for forty minutes 
further a heat equal to the whole power of the furriace. The 
crucibles were fafely withdrawn, and, nen examined, the 
following facts prefented themfelves :— 

cc The outer crucible rernained entire; the fand, next, 
formed an entire veffel confiderably connected. The ‘feeond 
erucible was alfo found, but in the bottom of it I found an ir- 
regular metallic mafs, A {mall hole in the fide of the interior 
pot had allowed nearly one-half of the original weight of iron 
to pafs; the remainder of it, forming a very beautiful circular 
button, refted upon the bottom. The furface was cryftallifed 
in radii, fhooting from a central point upon the upper fur- 
face of the button. The colleétive weight was 1858 grains : 
lofs, 17 grains, = ;1, part the weight of the iron. When the 
metal was lodged i in the fmall crucible, the fides and bottom 
were glazed, as in the former experiment. 

III. “‘ The fame experiment was repeated with bottle 
glafs, and a fimilar length and degree of heat applied. The t¢~ 
duétion of the glafs was entire. Rheewixt the exterior and mid- 
dle crucible, the glafs appeared as an entire interpofed veffel, 
completely furrounding the two fmaller ones. Upon exa- 
minirig the interlor crucible, I found that the contaé of the 
bottle- -alats had fufed the cover of fire-clay fitted over the iron, 
and that the promifcuous fufion of the glafs and clay formed 4 
very fine dark-green tranfparent mafs, ‘beneath which lodged 
the metallic bution, The upper furface ftill preferved the 
acutenefs of the original angles upon one piece of iron; the 
others had refolved theists by fufion into a very fine i ingot 
of foft fteel with partially cryftallifed edges. The w eight of 
the whole was 1759 graing; lefs fon. when put in, five 
grains; ¢qual to ,:, + part of the whole.—I am convinced 
that by prolonging the heat ten minutes, the whole iron would 
haye entered into fufion. I would from this and other expe- 
Timents infer, that the iron is of more difficult carbonation 
‘when a fufed medium is made ufe of, than when either pure 
fand, pure lime, or clay, are ufed. 

IV. “ In order that no proof might be further wanting to 
eftablith the faét of the iron receiving the carbon from its fo- 

Dd2 lution 


204. Caner fon of Tron into Steel. 


Jution’in caloric, and to obviate any objection which migh’ 
probably be ftarted againft this, by fuppofing that the carbon 
might be conveyed through the porous medium of the earths, 
or the bottle- olafs, before it entered into fufion, I made the 
following experiment :—Having made a mould in fand, I 
poured into it thinly fufed calcareous ftone; and, while the 
fluid was thin, introduced a fmall rod of red-hot iron, fuf- 
pended by a very fmall brafs wire. The dimenfions of the 
rod were fo proportioned to the mould that 5-8ths of an inch 
of a viirid cruft encircled the iron on all fides. The wire 
became fufed and difengaged as the fluid was’ confolidatine, 
fo that every avenue to the iron was completely fhut up. The 
mafs was carefully cooled to prevent fhivering, and as care- 
fully heated, when introduced into the farts in a crucible 
inverted in one larger, and the vacancy betwixt each fhut up 


from air ‘by means of pounded bottle-glafs. A cover was | 


fitted-on, and a violent heat urged for nearly two hours. The 
crucibles were taken out, free from blemifh, and cemented as 
one compact mafs. When cool, I found the metal in the 
interior crucible refolved into a very fine ingot, which proved 
afterwards to be foft fteel; capable, however, of hammering 
and hardening to great advantage. The weight of fteel ob- 
tained was 1157 grains; left, 33 grains, = =; part of the 
whole. The fufed lime, which had formerly’ cooled of a 
pure whitifh porcelain colour variegated with blue ftreaks, 


was now of a fpongy brown colour, exaétly refembling the- 


Java of the blaft-furnace when oxygenated crude iron is. pro- 
duced. ‘This alteration was unqueftionably owing to the de- 
ficient weight in metal having tm part been oxydated by the 
interior air of the crucible, or by oxygen from the furnace, 
and united to the earth in the ftate of a fufed oxyde. The 
great difference in the lofs of metal fuftained in thefe two laft 
experiments muft be fought for in the quantity of iron taken 
up by the flux: im the’others, the folidity and tranfparency 
of the glafs were uncommonly fine; in thefe the flux was 
opaque, dark, and porous, evidently furcharged with iron. 

‘* It will appear from thefe experiments, that we are ftill 
without any fatisfactory or conclufive proof of the fteclifica- 


tion of iron folely by means of the diamond, 
F “ There 


Monument to Count Rumford. £05 


«« There is ohe experiment which would, if fuccefsful, efta- 
blith the point. C. Clouet calculates, that, to conftitute grey 
rude iron, 1-6th of carbon is neceflary. Were fix parts ‘of 
iron, and a diamond, equal to 1-6th of this, fubjected to the 
fame procefs as formerly, and the refult grey, or carbonated 
erude iron, inftead of ficel, the inference would be juft, and 
the conclufign fatisfatory.. » 

“ Tn the prefent fiate of my information, I doubt whether 
the diamond afforded even one particle of carbon to the iron. 
From many experiments, wherein I ufed very pure well char- 
red wood and ‘malleable iron, I uniformly found that the 
weight of the fteelified ingot nearly equalled the fum of that 
of the iron and carbon originally introduced: fo that, in 
place of having a lofs of real iron equal to 4, as experienced 
by the Parifian chemitts, had the diamond been taken “up 
by the iron, the ingot of Atecl, would have weighed within 
seo part of the aggregate weight of both, and from ; to 
+> part more than the iron, at firft introduced. 

“¢ So far as I have gone, I think my experiments quite 
conclufive: the others you mention fhall be attended to in 
due time.” vt 


MonUumMENT to Count RuMFORD. 


In. the introduction.to a German: tranflation of Count 
Rumford’s Effays, lately publithed at Weimar, we find, 
among other anecdotes relative to the author, an account “4 
a monument that was erected at Munich in the year 179% 
in commemoration of his public fervices. 

This monument, which is fituated in a’beautiful publiegar- 
den adjoining 'to the ramparts of the city, was erected (with- 
out the knowledge of the Count, while he was abfent from 
Bavaria,) by the principal inhabitants of Munich, with the 
permiffion and approbation of the late Eleé&or. « 

The monument is adolid pile of a quadrangular form, con- 
firucted‘of hewn ftone, about twenty feet in height; and it 
has two principal fronts, which are ornamented with feulp- 
ture and in{criptions. 

_ Upon one of thefe fronts theres a baffo relievo of twa 

figures 


206 ~ Menument to Count Rumford. 


ficures at whole length reprefenting the Genius of Plenty 
leading Bavaria by the hand, and ftrewing her path with 
flowers. Under this emblematical piece of feulpture, upon a 
broad tablet of Bavarian marble, there is the following i in- 
feription in the German language :— a 


LUSTWANDLER sTEH! 
DANK STZRKET DEN GENUS. 
. BIN SCHEPFERISCHER WINK CARL THEODORES, 
VON MENSCHENFREUNDE RUMFORD, 
MIT GEIST. GEFIHL, UND LIEB’ GEFAST, 
HAT DIESE EINMALS @DE GEGEND 
IN DAS WAS DU NUN UM DICH SIHEST 
VEREDELT. 


Which may be thus tranflated + 


Stay, Rambler ! 
Thankfulnefs increafes Enjoyment. 
The creative glance of Charles Theodore 
Rumford, the Friend of Mankind, 
With Genius, Tafte, and Love infpired, 
Changed this.once defert place 
Into what thou now beholdeft. 


Upon the oppofite front of the monument there is a me+ 
dallion of Count Rumford, as large as the life, reckoned 4 
good likenefs, and under it the following infcription :-— 


IHM 
DER DAS SCHMAEHFLICHSTE OEFFENTLICHER URBEL; 
DEN MUESSIGANG UND BETTEL TILGTE; 
DER ARMUTH HILF, GEWERB UND SITTEN, 
DER VATERLAENDISCHEN LUGEND 
$O MANCHE BILDUNGSANSTALT GAB: 
LUSTWANDLER GEH! 
UND SINNE NACH IHM GLEICH ZU SEEN 
>» N GEIST UND THAT, - 
UND UNS 
AN DANKs 


Luminous Appearance produced by Sugar. 407 
- In Englith as follows :— ; 


To Him 
Who rooted out the moft difgraceful of public Evils, 
- Tdlenefs and Mendicity ; 

Who relieved and inftruéted the Poor, 
And founded many Inftitutions 
For the Education of our Youth; 

Go, Wanderer! 
Strive to equal him 
In Genius and Activity, 
: And us 
In Gratitude! 


That Count Rumford may long live to enjoy the heart~ 
felt fatisfaQion that muft refult from the contemplation of 
the fuccefs of his labours in promoting the happinefs of man- 
_ kind, muift be the fincere with of every lover of {cience, and 
of every true friend to virtue and morality, 


LUMINOUS APPEARANCE PRODUCED BY SUGAR, 


In the procefs of breaking fine white fugar in a dark apart- 
ment, a very perceptible luminous appearance is. obferved, 
the caufe of which is as much unknown to us as that pro- 
duced by rubbing againft each other two flints, particularly 
thofe of Iceland, The following is offered by Dr. Juch*, of 
Wiirzburg, as a kind of explanation of this phenomenon: 

** While breaking refined fugar,”’ fays he, * in fmal] 
pieces with a hammer and blunt knife, I fuddenly perceived 
a very fingular fmell,- which had a great refemblance to that 
of fuming nitrous acid. I looked immediately round me to 
fee whether fome vefiel containing that acid might not be in 
the neighbourhood ; but I faw none, and was certain that 
nothing of the kind had been in the room. I then examined- / 
the cirenmftance more narrowly, and found, on breaking fine 
fugar, that a fmell fimilar to that of aquafortis was always. 
perceived by every perfon prefent. 

“This fimultaneous difengagement of light, and of the {mell 
of nitrous acid, I explain in the following manner :—When 


¥ In Scherer’s Journal der Chemie, Now 10+ 


fugar 


208° abate of Fron, —Eleéiricity of Tce... 


fagar is broken, a new furface being prefented to the ait a 
real acidifying proceis infantly sakes place: a fmall portion 
of the oxygen’ of the atmofphere unites itfelf with the fugar, 
but not enough to form faccharine acid, as the quantity is not 
perhaps fafficient. for that purpofe; bed at the-fame moment 
the atmofphere in‘contaét ‘with th the new furface of the fugar 
is fo changed, m regard to the proportion of its component 
parts, that it affects the olfactory organs in the fame manner 
as nitrous acid. This phenomenon may receive fome ses 
jluftration by repeating the experiment ua clofe vellel.’ 


A SINGULAR OXYDATION OF IRON. 


Dr. Juch alfo gives the following fingular nottce :— 

« | had,” fays he, “ a fmall leather flafk filled with iton 
filings, which } frequently ufed with my electrophorus both 
charged and uncharged. I had occafion one day for a quan- 
tity of pure iron, and, having no. other at hand, had recourfe 
to the filings in the flafk, which I knew were pure. I emp- 
tied it on a picce of paper. I laid the paper on my hand in 
order to convey it to the place of its deflination; but T had 
fearcely held it a few feconds when I perceived’a {trong heat, 
which inereafed fo much that [ could no longer hold the 
paper. -Some minutes after, the paper became brown, and 
at length took fire. It did not, however, flame. The iron 
Ainge were’ in a ftate of ignition; and. when the heat‘had 
décrenleay } foumd the iron converted into a highly friable 
exyd.” 


ELECTRICITY GF ICE, .. 


The fame author mentions, that.eleétric fparks: may Bis 
sbtained by the ufual manipulation froma cylinder of ice. 
Thole who may not be afraid of the labour, can make the ex+ 
periment at the temperature of — 16; R. = — 57125 Pabr. 


THE 


zt * 


PHILOSOPHICAL MAGAZINE. 


DECEMBER 1799. 
ee ee eS : 


{. On different Sorts of Lime ufed in Agriculture. By 
SMITHSON TENNANT, E/g. F.R.S.* 


if WAS informed laft fummer, that, in the neighbourhood 
of Doncafter, two kinds of lime were employed in agricul. 
ture, which were fuppofed to differ materially in their effects. 
One of thefe, which was procured near the town, it was ne- 
ceffary to ufe fparingly, aud to fpread very evenly over the 
land: for it was faid, that a large proportion of it, inftead of 
increafing, diminithed the fertility of the foil; and that, 
wherever a heap of it was left in one fpot, all vegetation was 
prevented for many years. Fifty or fixty bufhels upon an 
acre, were confidered to be as much as could be ufed with 
advantage, The other fort of lime, which was obtained from 
a village near Ferry-bridge, though confiderably dearer from 
the diftant carriage, was more frequently employed, on account 
of its fuperior utility. A large quantity was never found 
to be injurious; and the fpots which were entirely covered 
with it, inftead of being rendered barren, became remark= ~ 
ably fertile. The different properties afcribed to thefe twe 
kinds of lime were fo very diftin@t, that it feemed probable 
they could not be imaginary; and it therefore appeared to 
be worth the trouble of afcertaining them more fully, and 


* From the Phil. Tran/. of the Roval Society for 1799, Fart IT. 
Vou, V. Ee of 


gto On different Sorts of Lime ufed in Agricultures 

of attempting to difeover the nature of the ingredients fram 
whence the difference arofe. For this purpofe I procured 
fome pieces of cach fort of limeftone, and firft tried whas 
would be their effect upon vegetables, in their natural ftate, 
by reducing them to coarfe powder, and fowing im them the 
feeds of different plants. In both kinds the feeds grew 
equally well, and nearly in the fame manner ag they would 
in fand, or any other fubftance whiel: affords no nourishment 
to Dewan Pieces of each fort of ftone were then burnt 
to linte j j and, after they bad been expofed for fome wecks te 
the air, that dec caufticity might be diminithed, fome feeds 
were fown in them. In the kind of lime which was found 
moft beneficial to land, almoft all the feeds came up, and 
continued to grow as long as they were fupplied with water 3 
atid the roots of the plants had many fibres, which had pes 
netrated to the bottom of the cup in which they grew. Upon 
examining the compofition of this fort of lime, it proved to 
confit entirely of calcareous earth. By its expofare to the 
dir for about three months, it was found to have abforbed 
4-5ths of the fixed air required to faturate it. Im the other 
kind, a few only of the feeds grew, and the plants produced 
from them had hardly any ftalks or roots, being formed al- 


mef{t entirely of the two feed-leaves, which lay quite loofe 


upon the furface. This fort of lime, being fpread upon a 
garden foil, to the thicknefs of about the tenth of an inch, 
prevented nearly all the feeds which had been fown from 
coming up, whilft mo injury was oceafioned by common 
Jimé ufed m the fame mauner. Upon examining the com- 
pofition of this fubltauce, which was fo deftructive to the 
plants, it was difcovered to contain three parts of pure cal- 
careous earth, and two of magnelia. The quantity of fixed 
sir which it had -abforbed, by being expofed for about the 
fame tithe as the pure lime juft errerttitined; was only 42 huns 
dredihs of that combined with it before it was burnt. 

As it feemed probable that the magnefia contained in this 
lime was the caufe of its peculiar properties, the following 
experiments were made, to determine the effects of that fubs 
flance upon the growth of vegetables. Some feeds, chiefly 
of colewort, which were preferred from their growing quickly, 

were 


4 


‘On different Sorts of Lime ufed in Agriculture. 2id 


‘were fown in uncalcined magnefia; but, though they {prouted, 
the leaves never rofe above the furface, and the plants were 
entirely without roots, nor did they appear to grow better in 
magnefia which had been wafhed in water containing fixed 
air, Calcined magnefia was, however, much more deftruc- 
_tive, as the feeds would not come up in it. To compare its 
effects on vegetables with thofe of lime, each of thefe carths 
was mixed, in different proportions, with fand, in fmall cups, 
in which feeds were then fown. The lime was obtained from 
marble; and, before it was put into the fand, was made to 
fall to powder, by being moiftened with water. In a mix- 
ture of four ounces of fand with three or four grains of cal- 
cined magnefia, it was a long time before the feeds came up, 
and the plants had hardly any roots or ftalks ; and, with ten 
grains or more of magnefia, there was no appearance of ye- 
getation, Thirty or forty grains of lime did not retard the 
growth of the feeds more than three or four of magnefia, and 
the injurious effects were not fo lafting. The lime, by ab- 
forbing fixed air, foon loft its deftructive properties ; fo that, 
after keeping thefe mixtures four or five weeks, feeds were 
found to grow in that with forty grains of lime, nearly as 
well as in pure fand; but, in that with four grains of mag- 
nefia, they produced only the feed-leaves, as was defcribe 
before. It was neceflary occafionally to break in pieces the 
{and which had fo much lime, as it would otherwife have 
een too hard to admit the feeds to penetrate through it. 
Plants will bear a much larger proportion of magnefia in ve- 
getable foil than in fand: with twenty grains, however, of 
calcined magnefia, in as much foil as was equal in bulk to 
four ounces of fand, the feeds produced only the feed-leaves 
without roots; and, with about forty grains, they were en- 
tirely prevented from coming up, 

In countries where the magnefian lime is employed, it 
was faid, that the barrennefs of any {pot on which a heap of 
it had been laid, would continue for many years. To learn 
how far it could by time be deprived of its injurious quali- 
ties, I procured fame pieces of mortar, made of this {pecies 
of lime, from two houfes, ane of which had been built three, 
and the other eight years: they were taken from the outfide 

Re 2 af 


212 On different Sorts of Lime ufed in Agriculture. 


of the building, where they had been expofed to the ‘air. 
After they were reduced to powder, feeds were fown in them. 
Only a few came up, and even thofe produced merely the 
" feed-leaves, without any roots. As plants would grow in 
the limeftone from which this fpecies of lime was formed, 
although not in the mortar made from it, I wifhed to know 
what proportion of the fixed air, originally contained in the 
limeftone, had been abforbed by the mortar. For this pur- 
~pofe a piece of it was finely powdered, to render it of an uni- 
form quality: it was then tried how much of this powder, 
and of the limeftone, would -faturate the fame quantity of 
acid: by this means I afcertained the proportions of lime- 
{tone and mortar, containing equal quantities of the magne- 


fian lime. ‘The fixed air being obtained from them in thofe — 


proportions, and meafured in an inverted veffel, with quick- 
filver, it was found that the mortar which had been expofed 
three years had abforbed 43, and that of eight years only 
47 hundredths of the quantity originally contained in the 
himeftone. I was not able to obtain any mortar which had 
been made earlier, though it might deferve to be known how 
much fixed air it was ultimately capable of abforbing. Com- 
mon mortar, which had been expofed to the air for a year 
and three quarters, had regained 63 hundredths of its full 
quantity of fixed air. 

As the preceding experiments were tried during the winter, 
in a room warmed by fire, perhaps under circumftances more 
favourable to vegetation, the fame quantity of magnefia would 
not be equally pernicious. 

Magnefian limeftone may be eafily diftinguifhed from that 
which is purely calcareous by the flownefs of its folution in 
acids, which is fo confiderable, that even the fofteft kind of 
the former is much longer in diffolving than marble. - From 
this property of the magnefian limeftone, there appeared to 
be reafon for fufpecting that the kind of marble which had 
been called Dolomite, from M. Dolomieu, who firft re- 
marked its peculiarity in diffolving flowly, might alfo be 
fimilar in its compofition. An analyiis of One fubftance 
was lately given in the Journal de Phyfique : but this is pro- 
bably erroneous ; as upon examining three fpecimens, they 

were 


oe oe: ¢ 


On different Sorts of Lime ufedin Agriculture. 233 


were found to confift of magnefia and calcareous earth, like the 
magnefian limeftone ; fo that it ought no doubt to be confider- 
ed as the fame Blecich of ftone, but j in a ftate of greater purity. 
The pieces of dolomite were from different ides ; one of them 
being found among the ruins of Rome, where it is thought 
to have come from Greece, as many ftatues of Grecian work 
manfhip are made of it, and no quarries of a fimilar kind are 
known in Italy ; the fecond was faid to have been thrown up 
by Mount Vefuvius; and the third was from Tona, one of 
the weftern iflands of Scotland. In many kinds of common 
marble, fmall particles and veins may be obferved, which are 
a long time in diffolving, Thefe, upon examination, I dif- 
covered to contain a confiderable proportion of magnefias 
but, as they were probably not guite free from the furround- 
ing marble, I did not afcertain the quantity precifely. 

The cryftallifed {truacture which may generally be obferved 


in the magnefian limeftone, feems to fhew that it has not 


been formed by the accidental union of the two earths, -but 
mutt have refulted from their chemical combination. The . 
dificulty of diffolving it, may alfo arife from the attraction 
of the different component parts to each other. The mortar 
formed from this kind of lime is as foluble in acids as com- 
mon marble; and the fubftances of which it confifts are eafily 
feparated. The magnefia may be taken from it by boiling it 
in muriated lime, and lime is precipitated by it from lime 
water; but neither of thefe effets can be produced by the 
fione before it is calcined. 

Magnefian limeftone is probably very abundant in various 
parts of England. It appears to extend for thirty or forty 
miles, from a little fouth-weft of Workfop in Nottingham. 
fhire, to near Ferry-bridge in Yorkfhire. About five or fix 
miles further north there is a quarry of it, near Sherburn; 
but whether this is a continuation from the ftratum near 
Ferry-bridge, I have not learnt. From fome fpecimens which 
were fent me, I find that the cathedral and walls of York are 
made of it, have not been able to learn whether there 
were any fhells in the limeftone of the tract of country be- 
fore-mentioned. In Mr. Marfhall’s account of the agricul- 
ture of the midland counties, he fpeaks of the lime made at 
Ercedon, near Derby, as deftruétive to vegetables, when ufed 

in 


O14 On different Sorts of Lime ufed in Agriculture. 

in large quantities. I therefore procured fome pieces of it, 
and they were difcovered to contain nearly the fame propor- 
tion of magnefia as that before defcribed. In this quarry the 
fione is frequently cryftallifed in a rhomboidal form; and 
petrified fhells, not calcareous, but fimilar in compofition te 
the ftone itfelf, are fometimes, but very rarely, found in it. 
This fubftance feems to be common in Northumberland. In 
the third yolume of the Annals of Agriculture, Dr. Fenwick, 
of Newcaftle, obferves, that the farmers of that country di- 
vide limes into hot and mild. The former of thefe is no 


doubt magnefian, as it has fimilar effects on the foil; and _ 


he remarks, that it is not fo eafily diffolyed in acids as the 
latter. At Matlock, in Derbyfhire, the two kinds are con- 
tiguous to each other; the rocks on the fide of the river 
where the houfes are built being magnefian, and on the other 
calcareous, The magnefian rock appears alfo to be incum- 


bent upon a calcareous ftratum; for, in defcending a cave 


formed in this rock, a diftiné&t vein of common limeftone 
say be obferved, which contains no magnefia. The latter 
firatum is very full of fhells; but, though there are fome alfo 
in the magnefian rock, yet they are very rare, In the fol- 
lowing tables, containing the analyfis of various fpecimens, 
fome other places are mentioned where this fubftance is 
found, but of which I received no further information. 
After 1t was known that the magnefian marble and lime-. 
flone confifted of the two earths, their proportion was at- 
tempted to be difcovered, by trying how much gypfum and 
Epfom falt could be obtained, by means of yitriolic acid, 
from a certain weight of each fpecimen. When the fuper- 
fluous vitriolic acid had been evaporated by heat, the Epfom 
falt was feparated from the gypfum by water. The refult of 
thefe trials is exprefled in the following table :— 


Dry Gypfum. Dry Epfom Salt. 


5 grains of limeftone from Breedon gave 3.9 3-15 


eerpetiinsnein Matlock - 3.95 2.9 
eomenie Workfop - 3.8 re 
a York - 3.8 LM 
3.grains of calcareous {par, and 1 grain} . 
of calcined magnefia, gave rm a 3:9 7 
6 As 


On different Sorts of Lime ufed in Agriculture. 41§ 


. As the preceding method of eftimating the quantities of 
magnefia ‘and calcareous earth is liable to confiderable error, 
I afterwards examined them in the following manner, which 
feems capable of great exactnefs :—Twenty-five grains of 
each fubftance were diffolved, by marine acid, in a cup of 
platina, and, after the folution was evaporated to drynefs, 
it was made red-hot for a few minutes. The mafs remain- 
ing in the cup, which confifted of muriated lime, and of the 
magnefia freed from the acid, was wafhed out with water, 
and poured into a phial. There was then added to it a 
known quantity of diluted marine acid, fomewhat more 
than was fufficient to rediflolve the magnefia, and, after the 
folution, a certain weight of calcareous fpar, part of which 
would be diffolved by the fuperfluous acid. By the quantity 
of {par remaining undiffolved, it was learnt how much acid 
was required to diffolve the magnefia. The iron and argil- 
jaceous earth contained in fome fpecimens, were precipi- 
tated by the fpar, and therefore could not occafion any error. 
The calcareous fpar, however, diffolved more flowly where 
there was ar eiflaceous earth, as it became coated with its 
but this oritation was occafionally removed, and, in'‘al} 
the experiments, the fpar was left in the folution till it fuf- 
fered no further diminution, For this purpofe it was necef- 
fary to keep them flightly warm for fome days, during which 
time the phials were generally clofed, to prevent any efcape 
of the acid. 

The firft experiment in the following table was made upon 
known quantitics of magnefia and calcareous earth, to try 
the accuracy of the procels. For this purpofe, alfo, thé fe- 
tond was repeated upon a picce of limettone, previoufly pow- 
dered, to render every part of it of the fame quality. The 
firft column fhews the quantity of calcareous {par which 
Might have been diflolved by the acid required to take up 
the magnefia. The fecond fhews the correfponding quanti- 
ties of magnefia in 25 grains of each fubftance. The third 
exprefles the quantity of lime. This was inferred by fub- 
tracting the weight of the magnefia, and of the iron and 
clay, from 13.2 grains, the weight of the whole quantity of | 
earth in 25 grains of limeftone, This is probably not very 

: incorreét, 


216 Ondifferent Sorts of Lime ufed in Agriculture. 


incorrect, as, in two fpecimens which differed moft in the 
proportion of magnefia and lime, the weight of the two 
earths was nearly the fame. 

A picce of dolomite, from Rome, was wrapped in a thin 
leaf of platina, that no part of it might be loft, and, being 
then expofed to a ftrone heat, left of carth - 52.9 percent, 


~ Dolomite from Mount Vefuvius - Agee 
Breedon limcftone - ~ 52-4 
Calcareous fpar left of Jime - - 55:8 


Tn three of the experiments, alfo, the calcareous earth was 
precipitated by mineral alkali; and the quantity of it being 
tried by that of the marine acid required to diffolve it, it 
correfponded very nearly with that put down. 

A quantity of marie acid which would diffolve 15 grains 
of calcareous fpar, would alfo diffelve 5.5 of calcined mag- 
nefia, and 2.5 grains.of {par; fo that 12.5 grains of {par, re- 
‘quired the fame quantity of acid as 5.5 grains of magnefia. 

The magnefia ufed was yery pure, and made red-hot im~ 
mediately before it was weighed. 

VE eee EEN Be SCE NTR ND VRS Ae Ta Boh 2 Ee 


Quantity: of 
: ‘ thd acidy 
Subjlances examined. foie cup tae Quantity of Quantity of | Iron 
magnefia, magnetia. Jime. and 
would have clays 
diffolved. 
ist BES Iw oe Thea SEWN AS ~7_—_—_ 
Mixture of 5.5 grains of mag- 
nefia and 14 grains of calca- 
reous {pare = =} T20§ 5.5 4.8: ° 
25 grains of Brsedon Haetoae, 
TH ian of powdered = -] 11.53 5-071 7929 2 
5 grains from part of the fame 
powder - = - | 11.56 5.082 9-913 2 
25 grains of dolomite from 
Rome - - - | 12.2 $37 7.73 ms 
—— dolomite from sale 
Iona - - - - | 10.1 4.4 78 I of im 
—- Vefuvian dolo- 2 ftauce. 
mite - - - = | 10.38) | 4565 | 8.575 | sc6 
A fecond experiment, from Ms 
pam of the fame Vefuvian 2 
dolomite - - - | 1003 | 4411 8.849 | -cb 
25 grains of magnefian lime- : 
ftone from Wanfworth, near 
Doncafter —__ - - | 32.75 5.61 7634 +25 
—_—— Thorpe arch - f 1095 4.84 7.8 6 
—— Matlock - =] 12.5 La 7-388 | +3 ° 
York-minfter - | 11. - | 4-84 8.26 .r 
os Woikfop - -} 11.6 5.104. 7.496 | 6 
————-——- Sherburn - - | 11-5 5.08 7-56 56 
—————— Weftminfter-hall} 10.1 4-44, {1-837 av 
Il, Agenda, 


ferdages | 


1. Agenda, or a Colleétion of Obfervations and Refearches, 
the Refults of which may ferve as the Foundation for « 
Theory of the Earth. By M. De Saussure. 


[Concluded from Page 140.] 


CHAP. XXIII. 


Inflruments neceffary for the Geolegical Traveller. 


I. ‘Tue moft neceffary inftrument is the miner’s hammer, 
It will be requifite to have two, of different fizes: one {mall, 
to break fmall fragments of rolled pebbles, by holding them 
in the left hand while you ftiike with the right. Its weight, 
including the handle, ought to be about ten ounces. The 
other muft be larger, to detach fragments of rock, and to 
break large pebbles: its weight ought to be quadruple that 
of the {mall one. When I travel on horfeback, I have thefe 
two hammers fufpended from the bow of my faddle. 

1. A. Two ftone-cutter’s chifels: one fmall, of from a line 
to a line and a half, to detach {mall cryftals, or other objects 
of fmall bulk; the other, feven or eight lines. 

2. To try the hardnefs of foffils, a piece of fteel to ftrike 
fire will be neceffary ; alfo a triangular file, pretty fine, and a 
firong bedkin of tempered fleel. 

3. Nitrous acid, with M. De Morveau’s boxes of re- 
agents. 

3. A. An artificial magnet, in a cafe, with a fteel pivot 
on which it-can be placed, to try the magnetifm of foffils. 

4. A magnifying glafs of three inches focus, in order to 
enable the obferver to form a general idea of any foffil: an- 
other, of an inch focus, to examine its feparated parts; and 
one of five or fix lines for clofer examination. Thefe three 
magnifiers muft be always in the traveller’s pocket, or ready 
at hand: but, befides thefe, he muft have, for his clofet at 
home, a microfcope furnifhed with a micrometer. 

* 5. Telefcopes, to obferve inacceffible mines and diftant 
mountains. 

6. A pocket portfolio,-with prepared paper for writing ong 

Vol v; Ff With 


~ 


218 Hints for the Formation of 


with a pencil of tin folder, which it is not neceffary always 
to cut, and the writing of which is not fo eafily effaced as 
that of plumbago. In this portfolio the traveller mutt write 
out, on the fpot, the fketch of his journal, and infert fach 
obfervations as occur to him; but he mult take the trouble 
to tranfcribe thefe notes at more length, preferving the pri- 
mifive notes, which will always retain a character of truth, 
and for that reafon people are fond of recurring to them. 

7. Some quires of brown paper, a few fheets of which 
may be carried in the pocket for wrapping up on the fpot 
fpecimens of the flones you collect, the characters of which 
ought to be marked on the cover. You may afterwards pack 
them with hay into a bag deftined for that purpofe, until you 
have a fufficient quantity to form a box, which you may fend 
home by the public carriages wherever you find an oportu- 
nity; but, as it is fatiguing for the traveller to load his poc- 
kets during the time of bis excurfions, and as the guides often 
Jofe them on purpofe in order to get rid of them, I have be- 
hind my faddle two leathern bags, into which I put them till 
I come to fome halting-place, where I have time to pack 
them with hay mto a bag. M. Beffon recommends to thofe 
who undertake fea voyages to write with China ink the cha- 
racters which ought to accompany minerals in long paflages, 
becaufe common ink may be effaced by accidents. 

8. A blow-pipe, with its apparatus. As I make much 
ufe of this inftrament, which at length fatigues me, though 
I can blow with my cheeks without exercifing my breaft, I 
caufed to be confiruéted a pair of portable double bellows, 
the fides of which contain each fixty-two fquare inches. 
Thefe bellows can be fufpended from the edve of a table; 
and I put them in motion by pyeffing together, between my 
knees, the two handles, which afterwards feparate by the 
aétion of the fpring. This apparatus may be eafily ¢arried, 
and is very convenient. 

g. A graduated femicirele traced out on a copper-plate of 
a form exactly rectangular, with a plummet fufpended from, 
the centre of the femicircle. This femicircle is the moft 
convenient infirument for meafuring the inclination of ftrata, 
of veins and declivities ; and it may always be carried in a 
pocket .of the portfolio. 


Io. A 


| 


a Theory of the Earth. 219 


10, A compals, furnifhed with a crofs ftaff, to find the di- 
rection of mountains, chains, vallies, and ftrata. 

tr. Portable barometers with two mercurial thermome- 
ters; one affixed to a barometer to cftimate the temperature 
of the mercury in the latter, and the other with a bare bulb 
for meafuring the temperature of the air. Thofe who ftudy 
meteorology, as well as geology, ought to be furnifhed alio 
with an bygrometer and an electrometer. 

12. For afcertaining the temperature of the fea, at great 
depths, it will be neceflary to have a thermometer conftructed 
like that deferibed‘in my Travels through the Alps*: for 
Jakes, an apparatus like that pointed out ia the note of Sec- 
tion 1399, will be fufficient. am, 

13. Thofe who underttand a little geometry, ought to pro- 
vide themfelves with a fextant, having an artificial horizon, 
and alfo a chain, in order that they may be able to meafure 
a bafe, and thus take the altitude of an inacceflible peak, the 
breadth of a river, &c. &c. With this fextant they may 
alfo find the latitudes. In regard to the longitudes, they re- 
quire, befides in{truments, an expertnefs in this kind of ob- 
fervation, which cannot be attained but by mariners or pro- 
feffed aftronomers. 

14. It will be neceffary alfo to have within reach tools for 
tepairing an inftrument in cafe it fhould happen to be de- 
ranged; fuch as pincers, files, turnfcrews, compaffes, gim- 
blets, wire, needles, thread, and packthread. 

15. Laftly, fome good map, pafted on canvas, of the coun- 
try you propofe to examine; and this map ought frequently 
to be compared with your itinerary, and the bearings given 
by your compafs, 

16, In regard to the care required for the traveller’s perfon, 
he muft have a light drefs made of cloth, without lining, of 
a white colour, as well as his hat, that he may be lefs ex- 
pofed to the heat of the fun’s rays; with jackets, fome cool for 
the warm regions and the vallies, and the other warm for 
the cool regions and eminences; a good great coat; green 
fpeGtacles, and a black crape, to fecure the eyes and face from 
the fuow. Laftly, if he is to pafs the night in the open air, a 

* Scétion 13097, Plate 1, fig. 3. 
Ef. tent 


« 
220 Hints for the Formation of 


tent or cannonicre, a bear’s fkin to fleep upon, and woollen 
blankets. J 
17. A folid light walking-pole: mine for the high Alps 
is a young fir-plant, extremely dry, feven feet in length and 
18 lines in diameter at the lower end, which is fhod with 
iron taperiig to a {trong point. Thefe dimenfions may appear 
large, but nothing can be too ftrong for the fteep rocks, gla- 
ciers, and fnow, when you are obliged to take your point of 
fupport at a diftance from you, and to ret the whole weight 
of your body on your pole, by holding it in a fituation very 
niuch inclined, and even horizontal, as may be feen in the 
Vignette to the Firft Volume of my Travels through the Alps. 
—For mountains which are not fo fteep, the traveller may 
be fatisfied with poles of lefs ftreneth and fize; but it will 
ftill be neceffary that they fhould be four or five feet in height, 
and fufficiently ftrong that a perfon might be able to fupport . 
himfelf with his two hands by holding them in a horizontal 
fituation, according to ‘the attitude of the fmall figure which 
is on the Jeft fide at top of the before-mentioned vignette; for, 
in traverfing or defcending a rapid declivity, or in walking 
on the margin or edge of a precipice, the traveller mutt al- 
ways fupport himfelf by bis two hands, holding the pole to- 
~ wards the mountain, and not towards the precipice, as thofe do 
who have not learned the art of travelling through mountains. 
18. To prevent flipping on the hard fnow-ice, and -grafs- 
plats, which are ftill more dangerous, I would recommend iron 
cramps, fuch as thofe which I have caufed to be engraved in 
the. third plate of the firft volume, and which I have long 
ufed-with fuccefs. - In my laft excurfions, however, I pre- 
ferred fhoes, the thick foles of which were armed with flrong 
tacks, at the diftance of eight or nine lines from each other, 
The heads of thefe tacks are of fteel, and fhaped like a fquare 
pyramid: I have fome fmall ones, the points of which are 
only two lines and a half in height, and of about the fame 
breadth, for the fnow-rocks and grafs-plats; and others, of 
double thefe dimenfions, for the hard fnow. 
1g. In the laft place, with regard to provifions, when the 
traveller muft refide for a confiderable time in the defarts, at 
a diffance from habitations, and even huts, he may carry 
with 


a Theory of the Earth. 221 
with him fome falt or pickled meat; but M. Parmentier’s 
faloop of potatoes, with cakes of portable foup, and bread, 
will form the moft nourifhing food,, and what may be con- 
tained in the Jeaft room. A {mall iron chaffing-difh, a finall 
bag filled with charcoal, and a pan of tinned copper or iron, 
form my kitchen apparatus for the mountains: wooden plates 
and fpoons may be found in the remoteft huts. It will be 
proper, however, to carry always in the pocket a cup of 
gum elafiic, in order that the traveller may at all times eafily 
quench his thirft, a want to which he will be frequently ex- 
pofed in his excurfions. 

From what has been faid, it may be readily feen, that the 
fiudy of geology will not fuit the indolent or fenfual; for the 
life-of the geologue muft be divided between fatiguing and 
perilous journies, in which he is deprived of almoft all the 
conyeniences of life, and the varied and deep refearches of 
the clofet. But what is ftill more rare, and perhaps more ne-= 
ceffary than the zeal requifite to furmount thefe obftacles, is, a 
mind free from prejudice; filled with an ardent defire for the 
truth alone, rather than with a defire for raifing or deftroying 
fyftems; capable of defcending to minute details indifpenfibly 
neceflary for the correCtnefs and certainty of obfervations, 
and of rifing to grand views and general conceptions. Thofe 
fond of fuch fudies, ought not, vacipeaaene to be difcouraged 
by thefe difficulties ; there is no traveller who may not make 
fome good-obfervation, and bring with him at leaft one ftone 
worthy of being employed in the con{truction of this grand 
edifice. It is indeed poffible to be ufeful without attaining 
to perfection ; for I have no doubt that if the mineralogical 
travels, even the moft efleemed, and much more thofe of the 
author, be compared with thefe Agenda, there will be found 
in them many deficiencies, and many obfervations, either im- 
perfect, or even totally forgotten: but I have mentioned the 
reafon in the Introduction. Befides, feveral of thefe ideas 
did not occur till I had finifhed my travels; and for that rea- 
fon T laboured with more zeal on thefe Agenda, in the hope 
of rendering young perfons, on their entering this career, 
‘capable of performing what coft. me thirty-fix years of tra- 
yelling and ftudy, 


: 


Ill. Ox 


~ 222 7 


Ill. On the Nature and ConftruGtion of the Sun and Fixed Stars. 
By Wiii1aM Herscuer, LL.D. L.R.S. 


[Concluded from Page 123. ] 


Jy will now be eafy to bring the refult of thefe obfervations 
into a very narrow compafs. That the fun has a very exten- 
five atmofphere cannot be doubted; and that this atmofphere 
confifts of various elaftic fluids, that are more or lefs Incid 
and tran{parent, and of which the lucid one is that which 
furnifhes us with light, feems allo to be fully eftablithed by 
all the phenomena of its fpots, of the facula, and of the 
lucid furface itfelf. There is no kind of variety in thefe ap- 
pearances but what may be accounted for with the greateft 
facility, from the continual agitation which, we may eafily 
conceive, muft take place in the regions of fuch extenfive 
elaftic fluids. 

It will be neceffary, however, to bea little more particular 
as to the manner in which I fuppofe the lucid fluid of the fun 
to be generated in its atmofphere. An analogy that may be, 
drawn from the generation of clouds in our own atmofphere, 
feems to be a very proper one, and full of inftruétion, Our 
clouds are probably decompofitions of fome of the elafiic 
fluids of the atmolphere itfelf, when fuch natural caufes, as 
in this grand chemical laboratory are generally at work, act 
upon them: we may therefore admit, that in the very exten- 
five atmofphere of the fun, from caufes of the fame nature, 
fimilar phenomena will take place; but with this difference, 
that the continual and very extenfive decompofitions of the 
elafiic fluids of the fun are of a phofphoric nature, and at- 
tended with lucid appearances, by giving out light. 

If it fhould be objected, that fuch violent and unremitting 
decompofitions would exhauft the fun, we may recur again 
to our analogy, which will furnith us with the following. re-" 
flections. The extent of our own atmofphere, we fee, is {till 
preferved, notwith{tanding the copious decompofitions of its 
fluids in elouds and falling rain; in flafhes of lightning, in 
meteors, and other Juminous phenomena; becaufe there are 
frefh fupptics of elaftic vapours continually afcending to make 


9 : good 


On the Sun and Fixed Stars. 229 


good the wafle occafioned by thofe decompofitions. But it 
may be urged, that the cafe with the decompofition of the 
elatiic fluids in the folar atmofphere would be very different, 
fince light is emitted, and does not return to the fun, as clouds 
do to the earth when they defcend in fhowers of rain. To 
which I anfwer, that, in the decompofition of phofphoric 
fluids, every other ingredient but light may alfo return to the 
body of the fun. And that the emiffion of light muft watie 
the fun, is not a difficulty that can be oppofed to our hypo- 
thefis: for, as it is an evident fact that the fun does emit 
light, the fame objection, if it could be one, would equally 
militate again every other affignable way to account for the 
phenomenon. 

There are, moreover, confiderations that may leffen the 
preflure of this alledged difficulty. We know the exceeding 
fubtilty of light to be {uch, that in ages of time its emanation 
from the fun cannot very fenfibly leflen the fize of this great 
body. To this may be added, that, very poflibly, there may 
alfo be ways of reftoration to compenfate for what is loft by 
the emiffion of light, though the manner in which this can 
be brought about fhould not appear to us. Many of the ope- 
rations of Nature are carried on in her great laboratory which 
we cannot comprehend, but now and then we fee fome of 
the tools with which fhe is at work. We need not wonder 
that their conftruétion fhould be fo fingular as to induce us 
to confefs our ignorance of the method of employing them, 
but we may reft affured that they are not a mere /u/us na- 
ture. allude to the great number of {mail telefcopic co- 
mets that have been obferved, and to the far greater number 
fiill that are probably much too fmall for being noticed by 
our moft diligent fearchers after them. Thofe fix, for inflance, 
which my fitter has difcovered, I can from examination af- 
firm, had not the Jeat appearance of any folid nucleus, and 
feemed to be mere collections of vapours condenfed about a 
centre. Five more, that I have alfo obferved, were nearly of 
the fame nature. ‘This throws a myftery over their deftina- 
tion, which feems to place them in the allegorical view of 
tools, probably defigned for fome falutary purpofes to be 
wrought by thern; and, whether the reftoration of what is 

loft 


. 224 On the Nature and Conftruéiion 


lott to the fun by the emiffion of light, the poflibility of which 
we have been mentioning above, may not be one of thefe 
purpofes, I fhall not prefume to determine. The motion of 
the comet, difeovered by Mr. Meffier in June 1770, plainly 
indicated how much its orbit was liable to be changed by the 


a 


perturbations of the planets; from which, and the little agree-_ 


ment that can be found between the elements of the orbits 
of ali the comets that have been obferved, it appears clearly 
that they may be directed to carry their falutary influence to 
any part of the heavens. ; 
My hypothefis, however, as before obferved, does not lay 
me under any obligation to explain how the fun can fuftain 
the watte of livht, nor to fhew that it will fuftain it for ever ; 
and I fhould alfo remark that, as in the artalogy of generating 
‘clouds, I merely allude to their produétion as owing to a de- 
compofition of fome of the elaltic fluids of our atmofphere, 
that analogy, which firmly refts upon the faé, will not be 
lefs to my purpofe, to whatever caufe thefe clouds may owe 
their origin. It is the fame with the lucid clouds, if T may 
fo call them, of the fun. They plainly exift, becaufe we fee 
them; the manner of their being venerated may remain an 
hypothefis—and mine, till a better can be propoted, may ftand 
good; but, whether it decs.or not, the conlequences I am 
going to draw from what has been faid will not be affected 
by it. | 
Before I proceed I fhall only point out, that, according to 
the above theory, a dark {pot in the fun is a place in its at- 
mofphere which happens to be free from luminous decom- 
pefitions ;, and that facul are, on the contrary, more copious 
mixtures of fuch fluids as decompofe each other. The pen- 


“umbra, which attends the {pets, being generally depreffed,: 


more or lefs, to about half way between the folid body of the 
fun and the upper’part of thofe regions in which luminous 
decompofitions take place, muft of courfe be fainter than 
other parts. No fpot favourable for taking meafures having 
lately been on the fun, I can only judge, from former ap- 


pearances, that the regions in which the Juminous folar - 


clouds are formed, adding thereto the elevation of the facu- 
le, cannot be lefs than 1843, nor mec more than 2765 


miles’ 


of the Sun and Fixed Stars. 225. 


miles in depth. It is true that in our atmofphere the extent 
of the clouds is limited to a very narrow compafs; but we 
ought rather to compare the folar ones to the Juminous de- 
compofitions which take place in our aurora borealis, or lu- 
minous arches which extend much farther than the cloudy 
regions. The denfity of the luminous folar clouds, though 
very great, may not be exceedingly more fo than that of our 
aurora borealis. For, if we confider what would be the bril- 
hancy of a fpace two or three thoufand miles deep, filled with 
fuch corrufcations asewe fee now and then in our atmofphere, 
their apparent intenfity, when viewed at the diftance of the 
fun, might not be much inferior to that of the lucid folar 
fluid. 

From the luminous atmofphere of the fun I proceed to its 
opaque body, which, by calculation from the power it exerts 
upon the planets, we know to be of great folidity; and from 
the phenomena of the dark fpots, many of which, probably 
on account of their high fituations, have been repeatedly 
feen, and otherwife denote inequalities in their level, we 
furmife that its furface is diverfified with mountains and 
vallies. F 

What has been faid enables us to come to fome very im- 
portant conclufions, by remarking, that this way of confi- 
dering the fun and its atmofphere removes the great diflimi- 
larity we have hitherto been ufed to find between its condi- 
tion and that of the reft of the great bodies of the folar fyftem. 

The fun, viewed in this light, appears to be nothing elfe 
than a very eminent, large, and lucid planet, evidently the 
firft, or, mn firiétnefs of {peaking, the only primary one of our 
fyftem, all others being truly fecondary to it. Its fimilarity 
to the other globes of the folar fyftem with regard to its fo- 
lidity, its atmofphere, and its diverfified furface, the rotation 
‘upon its axis, and the fall of heavy bodies, leads us on to 
fuppofe that it is moft probably alfo inhabited, like the reft 
of the planets, by beings whofe: organs are adapted to the 
peculiar circumftances of that vaft globe. 

Whatever fanciful poets might fay in making the fun the 
abode of blefled f{pirits, or angry moralifts devife in pointing 
it out as a fit place for the punifhment of the wicked, it does 

VoL. V. Gg not 


226 On the Nature and Conftruétion 


not appear that they had any other foundation for their af- 
fertions than mere opinion and vague furmife; but now Ff 
think myfelf authowifed, «pon affronomical principles, to pro- 
pofe the fun as an inhabitable world; and am perfuaded that 
the foregoing obfervations, with the conclufions I have drawn 
from them, are fully fufficient to anfwer every objection that 
may be made againft it. 

It may, however, not be amifs to remove a certain diffi- 
culty, which arifes from the effect of the fun’s rays upon our 
globe. The heat which is here, at the diftance of 95 millions 
of miles, produced by thefe rays, is fo confiderable, that it 
may be objected, that the furface of the globe of the fun it~ 
felf muft be feorched up beyond all conception, . 

This may be very fubftantially anfwered by many proofs 
drawn from natural philofophy, which thew that heat is pro- 
duced by the fun’s rays only when they act upon a calorific 
medium; they are the caufe of the production of heat, by 
uniting with the matter of fire which is contained in the fub- 
{tances that are heated; as the collifion of flint and fteel will 
inflame a magazine of gunpowder, by putting all the latent 
fire it contains into action. But an inftance or two of the 
manner in which the folar rays produce their effect, will 
bring this home to our moft common experience. 

On the tops of mountains of a fufficient height, at an alti- 
tude where clouds can very feldom reach to fhelter them from 
the direct rays of the fun, we always find regions of ice and 
fnow. Now, if the folar rays themfelves conveyed all the 
heat we find on this globe, it ought to be hatteft where their 
courfe is leaft interrupted. . Again, our aéronauts all confirm 
the coldnefs of the upper regions of the atmofphere; and 
fince, therefore, even on our earth, the heat of any fituation 
depends upon the aptnefs of the medium to yield to the im- 
preffion of the folar rays, we have only to admit, that, on 
the fun itfelf, the elaftic fluids composing its atmofphere, and 
the matter on its furface, are of fuch a nature as not to be 
capable of any exceffive affection from its own rays: and, in- 
deed, this feems to be proved by the copious emiflion of 
them; for if the elaftic fluids of the atmofphere, or the mat- 
ter contained on the furface of the fun, were of {uch a nature 


5 ; as 


niece 


of the Sun and Fixed Stars. 227 - 


as to admit of an eafy, chemical combination with its rays, 
their emiffion would be much impeded. 

Another well known fa& is, that the folar focus of the 
iargett lens, thrown into the air, will. occafion no fenfible 
heat in the place where it has been kept for a confiderable 

- time, although its power of exciting combuftion, when proper 
bodies are Expoftd, fhould be fufficient to fufe the moft re- 
fractory fubftances *. 

Tt will not be Sieh ne to mention other objéétions, as I 
ean think of none that may be made but what a proper con- 
fideration of the foregoing obfervations will eafily remove ; 
fuch as may be urged from the diffimilarity between the lu- 
minous atmofphere of the fun and that of our globe will be 
touched upon hereafter, when I confider the objections that 
may be affiened againit the moon’s being an inhabitable fa- 
tellite. 

‘I thall now endeavour, by analogical reafonings, to fupport 
the ideas I have fuggefted concerning the conftruétion and 
purpofes of the fun; in order to which it will be neceffary 
to begin with fuch arguments as the nature of the cafe will 
admit, to fhew that our moon is probably inhabited. This 
fatellite is of all the heavenly bodies the neareft, and therefore 
moft within the reach of our telefcopes : accordingly we find, 
by repeated infpection, that we can with perfect enuifene 
give the following account of it :— 

It is a fecondary planet, of a confiderable fize; the furface 
of which is div erfified, like that of the earth, by mountains 
and vallies, Its fituation with refpeé to the fun is much 
like that of the earth, and, by a rotation on its axis, it enjoys 
an agreeable variety of feafons, and of day and night. To 
the moon our globe will appear to be a very capital fatellite, 
undergoing the fame regular changes of illuminations as the 
moon does to the earth. The fun, the planets, and the ftarry 
conftellations of the heavens, will rife and fet there as they 
do here ; and heavy bodies will fall on the moon as they do 


* The fubjeét of light and heat has been very ably difcuffed by Mr. 
De Luc, in his excellent work, Idées fur la Météorologie, Tome I. part 2, 
chap. 2. fection 2, De la Nature de-Feu; and Tome II. part 3. chap. 6, 
faétion 2. Des Rapports de la Lumiere avec la Chaleure dans ? Atmofpbere. 
" Ge2 on 


/ 


228 On the Nature and Conflru&ion 


on the earth. There feems only to be wanting, in order to 
complete the analogy, that it fhould be inhabited like the 
earth. 

To this it may be objected, that we perceive no large feas 
in the moon: that its atmofphere (the exiftence of which has 
even been doubted by many) is extremely rare, and unfit for 
the purpofes of animal life: that its climates, its feafons, and 
the length of its days, totally differ from ours: that without 
denfe clouds (which the moon has not), there can be no rain ; 
perbaps no rivers, no lakes. In fhort, that, notwithftanding 
the fimilarity which has been pointed out, there feems to be 
a decided difference in the two planets we have compared. 

My anfwer to this will be, that that very difference which 
is now objected will rather ftrengthen the force of my argu- 
ment than leffen its value: we find, even upon our globe, 
that there is the moft firiking difference in the fituation of 
the creatures that live upon it. While man walks upon the 
eround, the birds fly in the air, and fifhes fwim in water 5 
we can certainly not object to the conveniences afforded by 
the moon, if thofe that are to inhabit its regions are fitted to 
their conditions as well as we on this globe are to ours. An 
abfolute, or total famenefs, feems rather to denote imperfec- 
tions, fuch as Nature never expofes to our view; and, on this 
account, I believe the analogies that have been mentioned 
fully fufficient to eftablith the high probability of the moon’s 
being inhabited like the earth. 

To proceed, we will now fuppofe an inhabitant of the 
moon, who has not properly confidered fuch analogical rea- 
fonings as might induce him to furmife that our earth is in- 
halived, were to give it as his opinion that the ufe of that 
great body, whied he fees in his neighbourhood, is to carry 
about his little globe, that it may be properly expofed to the 
light of the fun, fo as to enjoy an agreeable and ufeful variety 
oF iNumination, as well as to give it light by reflection from 
the fun when direét day -light cannot be had. Suppofe alfo 
that the inhabitants of the fatellites of Jupiter, Saturn, and 
the Georgian planet, were to look upon the primary ones, to 
which they belong, as mere attractive centres, to keep toge- 
ther their orbits, to direct their revolution round the fun, and 

to 


of the Sun and Fixed Stars. 229 


to fupply them with reflected light in the abfence of direé& 
illumination. Ought we not to condemn their ignorance, as 
proceeding from want of attention and proper reflection? It 
is very true that the earth, and thofe other planets that have 
fatellites about them, perform all the offices that have been 
named for the inhabitants of thefe little globes; but to us, 
who live upon one of thefe planets, their reafonings cannot 
but appear very defective, when we fee what a magnificent 

dwelling-place the earth affords to numberlefs intelligent 
_ beings. 

Thefe confiderations ought to make the inhabitants of the 
planets wifer than we have fuppofed thofe of their fatellites 
to be. We furely ought not, like them, to fay ‘ the fun 
“© (that immenfe globe, whofe body would much more than 
<¢ fill the whole orbit of the moon) is merely an attractive 
** centre to us.””. From experience we can affirm, that the 
performance of the moft falutary offices to inferior planets is 
not inconfiftent with the dignity of fuperior purpofes; and, 
in confequence of fuch analogical reafonings, affifted by te- 
lefcopic views, which plainly favour the fame opinion, we 
need not hefitate to admit that the fun is richly ftored with 
inhabitants. 

This way of confidering the fun is of the utmoft import- 
ance in its confequences. That ftars are funs can hardly 
admit of adoubt. Their immenfe diftance would perfectly 
exclude them from our view, if the light they fend us were 
not of the folar kind. Befides, the analogy may be traced 
much farther. The fun turns on its axis: fo does the ftar 
Algol: fo do the ftars called @ Lyre, ¢ Cephei, » Antinoi, 
_@ Ceti, and many more; moft probably all. From what 
other caufe can we fo probably account for their periodical 
changes? Again, our fun has fpots on its furface: fo has 
‘the ftar Algol, and fo have the ftars already named, and 
probably every ftar in the heavens. On our fun thefe fpots 
are changeable: fo they are on the ftar o Ceti, as evidently 
appears from the irregularity of its changeable lufire, which 
is often broken in upon by accidental changes while the ge- 
neral period continues unaltered. The fame little deviations 
haye been obferyed in other periodical ftars, and ought to be 


afcribed 


230 On the ™ ature and Confiruction 


afcribed to the fame caufe. But if ftars are funs, and fans 
are inhabitable, we fee at once what an extenfive field for 
animation opens itfelf to our view. 

It is true that analogy may induce us to conclude, that, 
fince {lars appear te be funs, and funs, according to the 
common opinion, are bodies that ferve to enlighten, warm, 
and fuftain a fyftem of planets, we may have an idea of num- 
berlefs globes that ferve for the habitation of living creatures. 
But if thefe {uns themfelves are primary planets, we may 
fee fome thoufands of them with our own eyes, and millions 
by the help of telefcopes, when at the fame time the fame 
analogical reafoning ftill remains in full force with regard td 
the planets which thefe funs may fupport. 

In this place I may, however, take notice, that, from other 
confiderations, the idea of funs or ftars being merely the fup- 
porters of fyftems of planets, is not abfolutely to be admitted 
as a general one. Among the great number of very com- 
preffed ‘clufters of ftars I have given in my catalogues, there 
are fome which open a different view df the heavens to us. 
The ftars in them are fo very clofe together, that, notwith- 
ftanding the great diftance at which we may fuppofe the 
clufter itfelf to be, it will hardly be poffible to affign any 
fufficient mutual diftance to the ftars compofing the ciufter, 
to leave room for crowding in thofe planets, for whofe fup- 
port thefe ftars have been, or might be, fuppofed to exift. It 
fhould feem, therefore, highly probable that they exift for 
themfelves ; and are, in fact, only very capital, Zuczd, primary 
planets, eomnabted together in one great fyflem of mutual 
fupport. 

‘As in this argument I do not indeed upon conjectures; 
but have actual obfervations in view, I {hall mention an in- 
ftance in the clufters No. 26, 28, and 35, VI. clafs, of my 
catalogue of nebule, and clufters of ftars. (See Phil. Tranf. 
Vol. LXXIX. Part II. p. 251.) The ftars in them are fo 
crowded that I cannot conjecture them to be at a greater 
apparent diftance from each other than five feconds, even 
after a proper allowance for fuch ftars, as, on a fuppofition of 
a globular form of the clufter, will interfere with one another, 
has been made. Now, if we would leave as much room be: 

tween 


ee ee ee eel eee 


a 


le i a la a a ttn ti ti et i 


of the Sun and Fixed Stars. 231 


tween each of thefe ftars as there is between the Sun and Si- 
rius, we muft place thefe clufters 42104 times as far from 
us as that flar is from the fun. But, in order to bring down 
the luftre of Sirius to that of an equal ftar placed at fuch a 
diftance, I ought to reduce the aperture of my 20-feet tele- 
{cope to lefs than the two-and-twenty ce part of an 
inch; when certainly I could no longer expect to fee any 
ftar at all. 

The fame remark may be made with regard to the number 

of very clofe double ftars, whofe apparent diameters being 
alike, and not very fmall, do not indicate any very great mu- 
tual diftance: from which, however, muft be deducted all - 
thofe where the different diftances may be compenfated by 
the real difference in their refpective magnitudes. 
. To what has been faid may be added, that, in fome parts 
of the milky way, where yet the ftars are not very fmall, 
they are fo crowded, that in the year 1792, Aug. 22, I 
found by the gages that, in 41 minutes of time, no lefs than 
258 thoufand of them: had paffed through the field of view 
of my telefcope *. 

It feems, therefore, upon the whole, not improbable that, 
in many cafes, ftars are united in fuch clofe fyftems as not to 
Jeave much room for the orbits of planets or comets; and 
that confequently, upon this account alfo, many ftars, unlefs 


* The ftar-gages ran thus: 
From 19" 35/to 19" 5x! 600 ftars in the field 
19 51—19 57 440 
19 57-20 12 360 
20 12—-20 16 260 
. The breadth of the fweep was 2° 35’, the diameter of the field 15’, and 
the mean polar diftance 73° 54’. Then let 
F, be the diameter of the field of view, 
$, the number of ftars in each field, 
B, the breadth of the fweep, plus F, 
T, the length of the fweep, exprefled in minutes of fpace, 
¢ the fine of the mean polar diftance, 
C, the conftant fraétion ,7854, 
and the ftars in thefe four fucceffive fhort fweeps will be found by the 


BTS¢ Bi , 
expreffion aC equal to 133095. 36601. 74566. 14419. or in all 258981. 
We 


232 On the Sun and Fixed Stars. 


we would make them mere ufelefs brilliant points, may them- 
felves be lucid planets, perhaps unattended by fatellites. 


POSTSCREPT. 


The following obfervations, which were made with an im- 
proved apparatus, and under the moft favourable circum- 
ftances, fhould be added to thofe which have been given. 
They are decifive with regard to one of the conditions of the 
jucid matter of the fun. 

Nov. 26, 1794. Eight fpots in the fun, and feveral fub- 
divifions of them, are all equally depreffed, 

The fun is mottled every where. 

The mottled appearance of the fun is owing to an inequa- 
lity in the level of the furface. 

The fun is equally mottled at its poles and at its equator ; 
but the mottled appearances may be feen better about the 
middle of the dife than towards the circumference, on ac- 
count of the fun’s fpherical form. 

The unevennefs arifing from the elevation and deprefiion 
of the mottled appearance on the furface of the fun, feems in 
many places to amount to as much, or to nearly as much, as 
the depreffion of the penumbre of the fpots below the upper 
part of the. fhining fubftance, without including facule, 
which are protuberant. 

The lucid fubftance of the fun is neither a liquid nor an 
elaftic fluid; as is evident, from its not inftantly filling up the 
cavities of the fpots, and of the unevennefs of the mottled 
‘parts. It exifts, therefore, in the manner of lucid clouds 
fwimming in the tranfparent ‘atmofphere of the fun; or ra- 
ther, of luminous decompofitions taking place within that 
atmofphere. 


IV. ExiraS 


YV. Extradt of a Memoir, and Experiments on the Nutrition 
of Plants. By M. Rarfy, Meffer 4 in the Office of Com 
merce at Copenhagen *, ‘ 


H ASSENYRATZ confiders carbon as the fubftance which 
nourifhes vegetables +. Ingenhous, in his work on the nu- 
trition of plants, publifhed in 1797; endeavours to prove, 
that if carbon has any influence in this refpeét, it can be 
only in the ftate of carbonic acid, as that acid is abforbed 
and decompofed ¢ by vegetables ; while the ligncous carbon, 
furnifhed by Nature, produces no effeé&t on the expanfion of 
plants. Mr. A. Young has endeavoured to demonftrate the 
fame thing by experiments. M. Rafn, defirous of difcover- 
ing the truth amidft thefe contradi@ory opinions, made, for 
three years, a feries of experiments, from which he con- 
cludes, by the expanfion, fize, and colour of the plants em- 
ployed, that carbon, either vegetable or animal, has a de- 
cided influence in the nourifhment of vegetables. What is 
new, and particularly worthy of remark in thefe refearches, 
is, that, according to M. Rafn, the carbonic acid produces 
exactly the fame effeét as charcoal of wood. The following 
are the, experiments which conduéted the author to iis 
refult :— 

Having half filled a large box with brick-kiln rubbith, or 
pounded tiles, which he covered with a layer of vegetable 
earth, he placed over the latter a ftratum of carbonate of 
Jime (pounded limeftone) and alum, and then two or three 
of vegetable mould, in which he fowed barley. He pre- 
fumed that the fulphuric acid of the alum, abandoning the 
argil to join the lime, with which this acid hus greater affi- 


* Tranflated fiom the Danith, with notes by C. Vauquelin and Brogy 
niart. 

t This opinion of C, Hafenfratz appears to be very probable; but, as 
he fays, the caibon muft be held in folution by hydrogen gas, by water, 
by that faponaceous extraét which feparates from vegetables when in a 
ftate of putrefydlion, or by any other liquid. 

{ This decompofition is poflible, but it has not yet been proved by 
any direét experiment, 


Vou. V, Wh nity, 


234 > Extradi of a Memoir, and 


nity, the carbonic acid gas would be difengaged, which 
would furnith the means of knowing its inficiériee on the 
‘vegetation. Another box was. filled merely with mould, a 
third merely with charcoal, and a fourth with animal ear- 
‘bon. Thefe were to be anaes ed in comparative experi, 
ments, and barley was fown in them all. 

Though the plants which germinated in the firft box were 
fown in a ftratum of mould about two or three inches in 


thicknefs, they had no refemblance, either in ftrength or co-_ 


lour, to thofe fown in the fecond box filled with mould alone; 
but they had, on the other hand, fuch a perfect refemblance 
to thofe of the third box filled with charcoal, that it would 
have been difficult to diftinguifh the difference. This refem- 
blance continued feveral weeks, after which they feemed to 
have not quite the fame vigour as thofe which grew in the 
charcoal, for which itis not difficult to afign a reafon. The 
enna, oan el himfelf that a _decompofition had really 
taken , becanfe, on exainining the firft bax in autumn, 
he found fin fulphat of Jime had been formed. Thefe ex- 
periments feem proper to conduct to a knowledge ef the man- 
ner in which plants attract the carbonic principle, which all 
the refearches of the aythor demonftrate to be neceffary for 
yigorous vegetation. He proppfes to repeat them on a larger 
fcale, and to vary them as much as poflible*. He repeated, 
feveral times, thofe of M. Humboldt on germination, accele- 
rated by the oxyget rated muriatic acid, and always with fuccefs, 
though with this difference, that this acid did not fayour ve- 
getation fo much as that philofopher afferted. 
M. Rafn fowed barley i in a mixture of mould, fand, and 
quanganefe, in order to fee whether the oxy gen gas would 


* Thele experiments would be more conclufive had net the authoy 
added mould in the boxes into which he put the rubbifh. It is well 
known that mould contains a great quantity of carbon, exactly in the ftate 
wiich renders it fit for the nutrition of vegetables. 

Mi. A. Young. on the other hand, arekte: that plants graw exceedingly 
tll in charcoal: and this oblervation agrees more with the others, and 
with the reafoning, which induces us to believe that carbon muft be dif. 
folved to enter into combination with the other principles of vegetables, 
‘As Pp layts, grow exccedingly well in pure water till a certain period, it 
would appear that they ov ght to ryt equally well m watered a 


tha 7 ) 2 Int 


Sif 


ts 


Experintents 61 the Nutrition of Plants. »95 
hoot be difengaged in fuch a manner as to produce fome effect 
on plants. At firft he obtained no effeét; but having wa- 
tered this box with diluted fulphuric acid; he remarked that 
the barley vifibly grew falter in this box than in thofe not 
watered in the ase manner *, 

Of all the mixtures which he tried for fowing, none ap- 
peared to him better than that of equal parts of charcoal, 
mould, and fand, moiftened with water filled with infufion 
animals, which may be eafily obtained by fieeping flax in 
the water deftined for that purpofe. He obferves, on this 


occafion, that, of all the fubftances he tried, flax is that which 


furnifhes the moft of thefe animalcule. An incredible mul- 
titude of them are found in the water in which women dip 
their fingers when they are employed in {pinning. The 
Water put into a veffel for that ufe in the mornifig, is found 
filled with them in the evening. The author afcribes to 
thefe {mall animals a much greater influence on vegetation 
than has hitherto been believed. ae, 

Haffenfratz relates, that he could not make plants vegetate 
‘well in fimple earths. The author afferts, that he hall great 
fuccefs when he reared them im pure filex, quartzy fand thrice 
wafhed, fine fand from the fea-fhore, &e. But thefe plants 
continued ftunted and pale, and their roots were twice as 


‘long as the whole of the part above the earth. In charcoal, 


on the other hand, the parts were, large and vigorous; they 


‘were of an exceedingly dark colour, and their reots were not 


a fixth part of the length of the plant itfelf +. 
Coal-afhes, on which the German and Englith farmers 


“beftow fuch praife, deftroy the plants if the foil contains an 


eighth part of that admixture. The leaves become faded, as 


~ ™ The fulphuric acid cold does not difengage the oxygen of the oxyd 


of manyanefe: befides, according to the experiments of Ingenhous, this 
acid alone, in fmall quantity, feems to have the property of rendering ve- 


“getation more active. 


+ The firft refults ave perfeétly fimilar to thofe obtained by C. Haffens 
fratz.. In regard tothe fecond, they depend om the purity of the chara 
coal employed, which may contain wood undecompoled, and confequently 


‘ difpofed to putrify, and to yield a liquid which may hold the carbon ia 
folution. 


Hhe if 


2396 On the Affaying of Iron Ores 
if {corched, at the end of from fifteen to twenty days, amd 
the plants themfelves die at the end of four or five weeks. 

No feed germinates in oil. A fingle gram of common falt ‘ 
in two hundred grains of water is fufficient to retard the ve- 
, getation of plants, and may even kill them: .if they are wa- 
tered with that faline liquor *. 

Shavings of horn, next to infufion animals, are’ the mot 
favourable to- vegetation : charcoal holds the third rank. 


V. On the Affaying of Tron Ores and Iron- ae by Fufon, 
By Mr. Davip Musuer, of the Clyde Iron Works +. 


I T will eafily be conceived, from the mode of operation 
which I have adopted, that, in order to procure accurate re- 
fults, the proportion: of flux muft be varied according to the 
mixtures in the iron-f{tones or ores; and that no univerfal 
folyent can be ufed as capable of affaying al/ ores. 

As the gradation of mixtures in. the ores is almoft imper- 
ceptible, there are, in fact, no fixed limits by which Nature- 
has diftinguifhed the various claffes: we find all the varieties 
diminifhing their predominant earth, and affuming, im equal 
proportions, thofe of each other, thus conftituting the clafs 
of equalifed mixtures; yet, here, the variety of combination 
ceafes not, the predominating earth gradually becomes the 
minor part of the mixture, and that which only held a fe- 
eond rank, as to quantity, is now the chief component earth ; 
the permutation goes round, til? the earth, which exifted im 
the moft {paring quantity, now predominates to excefs, 


* C, Sylveftore obtained a refult abfolutely fimilar, by employing ma- 
rine falt as manure. 

+ The prefent is a part of the communication from Mr. Mufhet which 
appeared im our Number for July laft, (Vol. IV.p. 178,) but by an over 
fight of the Editor was oniitted insits place., It contains the table of pro- 
portions alludsd: to in our Number for September laft (Vol. IV. p. 380.) 
requifite for the obtaining from all the various iron-ftones an accurate aflay, 
and fhould have maka es: followed Mr. Mufhet’s article given in our 
July number, 


~ and Tron-Stones by Pufions 239 
‘In fuch an infinity of variation it is difficult to arrange the 
combinations of which thefe fubftances are capable. To des 
rive the name of a clafs, or genus, from the predominancy of 
an earth, feems moft eligible; and to confider thofe as va- 
rieties of the fame clafs, which are altered by the proportion 
of the fecond and third mixtures. Again, each of thefe va4 
Fieties are fufceptible of a multiplicity of modifications before 
an earth is fo far diminifhed as to give an afcendency to an- 
other, or before the third rank ‘of proportion has affumed 
that of the fecond or firft. The fimple combination of the 
earths, and their degrees of predominancy, may be thus ar- 
ranged :-—~ 
rft Variety, 2d Variety. 
Iron = - fron 
Clay - + Clay 
Lime’ -. + «Silex 
Silex---<»~ 3; Lime 
fron - -  -Fron 
Caleareous iron-ftone ae 4 r a ‘e 
Silex +) =) Chy 
Iron - - Iron 
Silex - - _Salex 
Lime - =~ Clay 
Clay = = 


Argillaceous iron-ftone 


———- 


As thefe become varied, they form 
the clafs of equalifed mixture, 


Siliceous iron - ftone 


'¢ 
5 
@ 
Qo 


To affay any of thefe varieties, a flux peculiar to the na- 
ture of the mixture is neceflary; fo that the changes of pro- 
portion in the folvent ought to extend to feven, including 
the clafs of equalifed mixtures, in order that the precife fame ~ 
quality of crude iron may be produced from all the varieties 
of iron-ftone. The modification of each variety will be: 


found to be fufficiently accurate, if affayed by the flux pecu- 


Kiar to itfelf. The arrangement of the three claffeés of ores 


into two varieties, each forming a diftin@ {tage of combina- 


"tion, indicated by the predominancy of the firft and fecond 


earth, are, with the neutral clafs, fuffiiciently minute for any 


purpofe in the affay-furnace, and are fufficient to form an 


7 accurate 


/ 


2938. On the Affaying of Iron Ores, &e. 


accurate and extenfive knowledge of the analogy of thefe res 
_ fults with thofe in the blaft-furnace. 


TABLE of PROPORTIONS of FLUXES. 
Let the earthy part of an argillaceous ore be compofed of 
clay 9, lime 6, fand 3 = 18. 
To affay 4 troy ounces of thisore . - or 1920 grains, 


add 4 bottle glafs  — 1920 
3 chalk — 1440 | 

of charcoal — 240 

11> 5520 


Let the fecond variety of argillaceous ores contain, clay 10, — 
filex 7, lime 3 = 20, 


In this cafe, 4 ounces troy of ore - or 1920 grains, — 
would require 4- - bottle glafs — 192° | 
4 chalk — 1920 . 

o% —— charcoal — 360 . 

122 ; 6120 | 


Let the firft variety of the calcareous genus of iron-ftone 
be fuppofed to contain, of earthy mixtures, lime 14, clay 65 — 


filex 4 = 24. 4 
When this iron-ftone is to ba affayed, 
to 4 ounces troy - - or 1920 grainsy 
add 5 bottle glafs - — 2400 

a3, chalk — — 720 
of charcoal _—- — 360 
11t 5400 


Again, let the fecond variety of the calcareous genus be 
fuppofed to contain, lime 10, fand 6, clay 4 = 20. 
I would add to 4 troy ounces - or 4920 grains, — 


4 bottle glafs — 1920 
2 chalk — 960 
ot charcoal -— 240° 


1O; 5040 


On the Origin of Gum Sandarac, &c. 239 


Let the firft variety of filiceous ores be fuppofed to contain, 
filex 12, clay 8, lime 5 = 25. 
~ For an affay of 4 troy ozs. of ore = or 1920 grains, 


add 4 chalk — 1920 
3 bottle glafs — 1440 

o2 charcoal — 360 
“113. . 5640 


And, laftly, let the fecond variety of this genus of iron- 
fione be fuppofed to contain, filex 10, lime 7, clay 5 = 22. 
To 4 troy ouncesofthe ore - or 1920 grains, 


add 3: chalk — 1680 
3 —— bottle glafs — r440 
of charcoal — 360 
oy: ; 5400 


Clafs of equalifed mixtures, con:pofed of, clay 7, lime 7, 
fen. 7.2721. 


To aflay of thisore 4 troy ounces - or 1920 grains, 
add 35 bottle glafs — 1680 
ii chalk — 1200 
ot —— charcoal -— 240 
10! - 5040 


VI. On the real Origin of that Refin known under she; Name 
of Sandarac, and that of Gum Arabic. By M. Scuous- 
BOE rr ¥ 


Coun Sandarac is an article of trade brought from the 
fouthern provinces of the kingdom of Morocco. About fix 
_ ar feven hundred quintals of it are exported every year from 
Santa Cruz, Mogador, and Saffy. In the language of the 
country it is called El graffa. The tree which produces it 
is a Thuia, found alfo by M. Vahl in the kingdom of 


* From a Danifh Journal, entitled, The Phyfical, Medical, and Econo- 
pical Library, Part 1II. 1759. 
Tunis, 


- 


240 - On the Origin of Gum Sandarac, 


Tunis *. It was made known feveral years ago by Dr. — 
Shaw, who named it, Cypreffus fruétu quadrivalvi, Equifeta 
inflar articulatis; but neither of thefe learned men was. ac- 
quainted with the economical ule of this tree; probably be- 
caufe, being not common in the northern part of Barbary, 
the inhabitants -find little advantage in collecting the refin 
which exudes from it. This refin hitherto has been aferibed 
to the Juniperus communis, Juniperus Lycia, or the Cedar of 
Lebanon, without reflecting that the Juniperus communis 
does not grow in Africa, and Sandarac feems to belong eXx- 
clufively to that part of the world. M. Schoufboe, who faw 
the fpecies of Thuia in queftion, fays that it does not rife to 
more than the height of twenty or thirty feet at moft, and 
that the diameter of its trunk does not exceed ten or twelve 
inches. It diftinguifhes itfelf, on the firft view, from the 
-two other fpecies of the fame genus, cultivated in gardens, 
by having a very diftin& ‘runk, and the figure of a real tree ; 
whereas in the latter the branches rife from the root, which 
gives them the appearance rather of bufhes. Its branches 
alfo are more articulated and brittle. Its flowers, which are 
not very apparent, fhew themfelves in April; and the fruit, 
which are of a {pherical form, ripen in September. When 
a branch of this tree is held to the light, it appears to be in- 
terfperfed with a multitude of tranfparent veficles which con- 
tain the refin. When thefe veficles burft in the fummer 
months, a refinous juice exudes from the trunk and branches, 
4s is the cafe in other coniferous trees. This refin is the 
Sandarac, which is eolleGted by the inhabitants of the coun- 
try, and carried to the ports, from which it is tranfported ta 
Europe. It is employed in making fome kinds of fealing- 
wax, and in different forts of varnifh, In 1793 a hundred 
weight of it coft in Morocco from 13 to 13; piaftres, which 
make about 3/. 5s. to 3/. 7s, and 6d. fterling, The duty 
on exportation was about 7s. 6d. fterling per quintal. 
Sandarac, to be good, mutt be of a bright-yellow colour, 
pure and tranfparent, It is an article very dificult ta he 


* A complete defcription of it, with a good figure, may be found in 
his work entitled, SyaSol. Botan. Part IL. p, 96. Plate XLVI, under 


the name Thuia articuleta. 
adulterated, 


and Gum Arabic. — 64 1 


adulterated. Care, however, muft be taken that the Moors 
do not mix with it too much fand. It is probable that a 
tree of the fame kind produces the gum fandarac of Senegal, 
w ae is exported in pretty cohtideraie quantities. 

' Another article of commerce in which the kingdom of 
Morccco participates with Senegal, i is that gum called Gum 
Arabic, known by the name of 4/ lei/k. The tree which 
produces it grows only in the feuthern provinces of that 
ftate. The quantity of this article exported.to the different 
parts of Europe from the ports of Morocco may amount to 
about eight or nine quintals. M. Schoufboe fays, that this 
tree is the Mimosa nilotica, named in the country A/ thlah; 
but this is no reafon w hy the fame kind of gum fhould not 
be collected in the more fouthern countries of Africa from 
the Mimofa Senegal, and even from other trees of the fame 
fpecies, as we are told by various authors. In Barbary the 
people make a difference between the gum of Senegal and 
that of the country. The former is preferred on account of 
its purity, whitenefs, and tranfparency, which in general are 
the properties fought for in this article. 

_ The gum which I colleéted myfelf in the proyince of 
Mogador, fays M. Schoufboe, exudes frona the trunk and 
branches of the tree, in the fame manner as that of our 
fruit-trees. It is in round lumps, of the fize of a hazle-nut, 
or rather that of a walnut. Thefe lumps; indeed, by die: 
coming united to each other, form mafles fometimes of the 
fize of the fift, or even of the head; but this only happens 
in confequence of the adhefion which takes place between — 
the pieces of gum, when ftill frefh, after they have been de- 
tached from the tree, and chiefly at that part which was at- 
tached to the bark, where the refinous juice has not had time 
to harden. If earth, fmall ftones, and other foreign bodies, 
are fometimes found in thefe maffes, it arifes from fraud ; 
and M. Schoufboe fufpeéts that this circumftance has given 
rife to the opinion of the gum being found at the bottom of 
the tree, and that it exudes from the roots, which, as he 
thinks, is void of foundation. Were this the cafe, it appears 
to him that, befides the earth and fand with which the gum 
is accidentally dirtied, balls of thefe matters ought to be found), 
~YVot. V. li in 


} 
242 On the Peftilential Difeafes which 


in the infide, and even fo mixed with the mucilaginous fub- . 
ftance that it would be impoffible ever to purify it com- 
pletely; while, on the other hand, the gum which comes, : 
from Senegal is ftill purer than that of Barbary. str 

M. Schoufboe, however, obferves, that the fandarae and 
gum exported from the port of Saffy have a brown or red- 
dith colour; but he afcribes this colour to the quantity of 
the red oxyd of iron mixed with the foil of the province of 
Abda, where this port is fituated, This oxyd communicates 
its colour even to the whiteft wool; and the inhabitants of 
that province may be diftinguifhed by the reddith tint of their 
clothes, which cannot be entirely deftroyed by any procefs, 
In the months of July and Auguft, when heavy dews fall, 
the gum lofes a great deal of its tranfparency, as well as of 
its other good qualities. A hundred weight of this fubftance 
coft at Mogador, in 1793, about 2/. fterling, without in- 
cluding about 4s. cuftom-houfe duty, The gum does not 
appear to be employed by the inhabitants of Morocco for 
any purpofe whatever: the whole of what they collgét is fold 
to the different commercial nations of Europe, 


VII. On the Peffilential Difeafes which, at different times, ap- 
peared in the Athenian, Carthagian and Roman Armies, in 
the Neighbourbood of Syracufe. By the late E.H. Smiru, 
Phyfictan*. 


Section I. 


Syracuse, the moft beautiful of all the cities built by 
the Greeks, was founded by Archias, a Corinthian, of the 
yace of Hercules*. He firft expelled the natives from Orty- 
gia, where he commenced the city, which was afterwards 
extended to the neighbouring continent. This place, fo ce- 
lebrated in ancient hiftory, the birth-place of Archimedes, 
and theatre of many memorable tranfactions, now reduced to 
a miferable town, of inferior confequence even in Sicily, is 
fituated in north latitude 37° 5’, a little above Cape Paflara 
* From the American Metical Repofitory, Vol. II. No. 4. 


& ¢ Cicera in Ver. Act, II. Lib. ivy.§ 117. Thucydides, B. vi. ; 
(the 


appeared in the Neighbourhood of Syracufe. 243 


‘(the ancient Pachynum), the fouth-weftern extremity of the 


ifland of Sicily. 


The climate of Sicily, in general, is reprefented as favour- 
able to health*; and, notwithftanding its infular fituation, 
more analogous, in the qualities of temperature and humi- 
dity, to the hilly, than to the Atlantic divifions of South- 
Carolina and Georgia. The winter is remarkably mild: 
with the exception of a few days, it equals the fineft {pring 
weather in the North of Europe+, and the Eaftern States of 
America; and the fhade is found pleafant, in the middle of 
the day, even in the month of January t. At Syracufe, in 
particular, the feafon is fo little affected by the feverities of 
cold and tempe(t, that, during its whole courfe, and in its 
moft boifterous ftate, the fky is never totally obfcured for a 
fingle day §. Yet in this climate did Verres, the voluptuous 
pretor of Sicily, that monfter of atrocity and lafcivioufnefs, 
fo entirely feclude himfelf from all impaé and influence of 
the atmofphere, as only to learn the approach of fpring by 
obferving the dew gliften on the verdure which furrounded 
his palace |]. As the feafon advances, the heat rapidly in- 
creafes, till, in the funamer, it is no longer to be endured by 
ftrangers, and exertion, as well as enjoyment, is temporarily 
fufpended. In autumn, the frequent rains, which are com-. 
mon throughout this feafon, and the heats of the middle of 
the day, contrafted with the extreme chillinefs of the even- 
ings, render it lefs pleafant and falubrious than any other 
part of the year]. It is to the exceffive fultrinefs of the fum- 
mers that a late fenfible writer ** afcribes the imperfection of 

many, 


* Benige Berichten, &c. 7. ¢. Some account of the Proffian, Auftrian, 
and Sicilian monarchies, &c. See Monthly Review Enlarged, Vol. XIV. 
P- 491. 

4 Swinburne’s Travels in the Two Sicilies, Vol. TI. § 49. Dubl. edit, 

+ Keyfler’s Travels, Vol. II. p. 33.—Tranflation. 

§ Cicero in Ver, Aét, IL. Lib. v. § 26. 

|| Cicero in Ver. A&t. 11, Lib. v. § 12. 

q Travels in Sicily and Malta, by M. De Non, p. 307, 333, and 383.— 
Tranflation. 

** Eenige Berichten, &c.—‘* The foi! is exceedingly fertile; but, fro 
the great heat of the climate, many of our moft neurishing and refrefhj 

liz vegeta 


244 On the Peftilential Difeafes which 


many, and the total want of others, of the moft nutritious 
and refrefhing vegetables of the northern climates, in defpite 
of that fertility of foil which, from time immemorial, has 
conferred on Sicily the appellation of the granary of Europe. 

_ But, notwithftanding the general pleafantnefs and health- 
fulnefs of this ifland, the concurrent teftimony of ancient and 
modern writers evinces the noxious condition of particular 
places. The leaft ftagnant water is fufficient, in the heats 
of fummer, to poifon the atmofphere : its effets on the coun- 
tenances of the poor people, who live in its vicinity, are very 
evident; and a ftranger, who travels through the iland m 
this feafon, ought to avoid ever paffing a night near them *. 

. As foon as the fun enters the Lion, this country becomes 
the houfe of death: fevers, of the moft malignant kind, feize 
upon the imprudent or unfortunate wretch that fpends “a 
night near them (ponds and marfhes); and few efcape with 
fife, when attacked by fo virulent a diforder+.” Inftructed, 
probably, by experience of the calamities confequent on 2 
near refidence to marfhes and ftagnaut waters, the inhabi- . 
tants in various parts of Sicily have built their towns on ad- 
joining eminences $. To avoid the dangers which befet the 
ftranger in journeying through this country in the fultry and 
autumnal feafons, was probably one of the motives of the 
Roman preetors for performing the tour of the ifland in the 
time of harveft§. By a negleét of fimilar prudence, the ce- 
lebrated M. De Non became affe&ted with a violent fever and 
ague, after an incautious expofure to the heat of the fun and 
the chill of the evening, in an unwholefome part of the 
country, and in the month of September |. 

From this brief account of the climate. of Sicily, it will be 
evident, that, how favourable foever it may be efteemed, in 
general, to the health and longevity of the natives, and how 
vegetables will not thrive in it. Currants, rafpberries, and goofeberries, 
arc unknown to the natives; and foreigners, who have attempted to eulu- 
vate them, have never been able to fucceed.” 

* Eenige Berichten, &c. 

“4+ Swinburne’s Travels, Vol. II. § 49. Dublin edit. 
+ Swinburne’s Travels, Vol. II. p. 300. Dublin edit, 


Cicero in Ver. Aét. IL. Lib. v. § 80. 
De Non’s Travels, p, 333.—Tranflation. 


a) pleafant 


/ 


ae 


appeared in the Neighbourhood of Syracufe. 245 


_ pleafant foever many parts of it deferve to be confidered as a 


winter and even vernal refidence for ftrangers; yet, in other 
feafons, and particularly for vifitors from colder countries, it 
muft be in moft parts unfalutary, in others certainly fatal, 
and, in fome, not to be Jong continued in, with impunity, 
by the inhabitants themfelves. And, as this remark refers 
wholly to ordinary years and cea dante, it will afford 
fome ground for eftimating the effects of one of the moft un- 
healthy fituations in the country, in the fickly feafon of the 


-year, with a conftitution of the atmofphere favourable to 


epidemic difeafes, on an army of foreigners, tumultaous and 
ill-accommodated, worn down with fatigue, or finking in 
defpondency.—With this refleGtion imprefied on the mind, 
we may now proceed to a defcription of the city of Syracufe, 
and the country iramediately adjacent, as they exifted in an- 
cient times, occafionally fupplying iluftrations from the ac- 
counts of modern travellers. 

The once beautiful city of Syracufe confifted of five prin- 
cipal divifions, traces of all which are ftill difcernible. 1. The 
ifle Ortygia, Nafos, or Nafon: 2. Achradina: 3. Tyche, or 
Tycha: 4. Neapolis, or the new city: and, 5. Epipolz * 

Ortygia, enclofed by the two ports—the great port on the 
weft and the little port on the eaft, and conneéted with the 
continent by a bridge—is of an oblong form, and about two 
miles in circumference t. Here the original fettlemment com- 
menced, and this was always confidered as the wealthieft and 
moft defirable part of Syracufe. It was the ancient refidence 
of the kings ; and, in the time of Cicero, ftill contained the 
houfe of Hiero. It was ornamented with various public 
buildings, particularly the temples of Diana and Minerva; 
and, in part, watered by the poetic fountain of Arethufa. As 
the population increafed, the found, which divided Ortygia 
from the Continent, was filled up, and the ifle converted into 
a peninfulat. Carlos ILI. of Spain removed the earth by 
which they were united ; and Ortygia is again an ifland, and 
connected with, the Continent, as formerly, by a bridge §. 

* Cicero in Ver. Aét. II. Lib. iv. § 118. De Non, p. 304. et iene 
Swinbarnt, Vol. If. p. 309. + De Non. Swinburne. 

_.¢ De Non. Swinburne, § Brydone’s Tour, Letter xiii. 1 
| Th 


246 On the Peftilential Di ifeafes avbich 


The fituation of Ortygia is important, for it commands 
both the ports; and though fuppofed itfelf to be commanded 
by Achradina, yet, while that quarter of the city remained 
in the pofleffion of the Syracufans, together with the ifle, and 
the oppofite promontory of Plemmyrium, the town was nearly 
macceffible to a naval force*, At prefent Ortygia is the only 
city. To this ftate it was reduced by the Muflulmen. It is 


ftrongly defended towards the land, weakly towards thé fea- — 


fide. Its quay is fmall; its ftreets narrow, winding, and 
wretchedly built; and its population does not exceed 18,000 
petfons +. The fountain of Arethufa, after repeated changes 
of fituation t, is fiill difcoverable in the weft part of the ifle ; 
but its beauty and its honours have fled with the mythology 
to which it is indebted for its fame. 

Achradina. The quarter of Achradina, at the period to 
which this effay has particular reference, was the moft f{pa- 
cious, well built, and ftrongly fortified part of the city. It 
extends over two confiderable levels, divided by a natural 
wall of calcareous rocks; the one as elevated as Tyche; the 
other, and more confiderable, on a plane with Ortygia, and 
thence conferring on this quarter the character of the loweft 
divifion of Syracufe. The eaftern part was the moft com- 


modious, and not lefs extenfive than the modern Paris. The 


whole was adorned with a large forum, a beautiful portico, 
prytaneum, curia, and the temple of Jupiter Olympus; bor- 
dered on three fides by the fea, by the great port on the weft, 
the leffer on the fouth, and the port of Trogilus on the eaft ; 
and, on all fides, nearly impregnable. The rocks of this 
quarter of Syracufe, which are formed by marine depofitions, 
poffefs the fingular property of diffipating or abforbing the 
moifture of dead bodies { fpeedily, that they are preferved in 
vaults excavated for the purpofe, in their proper form and ha- 


biliments. Achradina is remarkably fertile, and naturally 


adapted for bringing to perfeétion every tropical production §. 


* De Non. Swinburne. 

+ Swinburne, Vol. LI. p. g11, 312z- De Non, p. 304. 

+ De Non, p. 307. 

§ Cicero ut antea-. De Non, p. 321, et fequent. Swinburne, Vol. I. 
P. 313) 344, 325+ Rollin’s Rom. Hift. Vol. V. p, 204. 
+ Tyche, 


>! al 
‘ 
co 


appeared in the Neighbourhood of Syracufe. 247 


Tyche, or the third city, extended northerly from Achra- 
dina to Epipole; commencing at the bottom of the port of 
Trogilus, which forms its fouth-eaftern boundary. Eat, it 
was defended by a ftrong wall; and a wall divided it, on the 
welt, from Neapolis. The famous gate of Hexapylon was on 
the eaftern wall, and oppofite to the little town of Leon. 
Tyche was ornamented by the Gymnafium; and, though 

' now defolate, was once filled with inhabitants. It is verv 
elevated, rifing in rapid gradation from the wall of Achra- 
dina *, - 

Neapolis ran nearly parallel, and in the fame direction 
with Tyche; terminating on the north, with that quarter, at 
Epipole. On the eaft, fouth, and weit, it was equally pro- 
tected by a wall. The upper and northern part of Neapolis, 
as of Tyche, was elevated; its fouth-weftern extremity was 
confiderably lower. A noble theatre, and the temples of 
Ceres and Bacchus, were its moft diftinguifhed ornaments ¢. 
_ Epipole was originally a piece of high ground without the 

' city, and afterwards fo little inhabited that it is not men- 
tioned by Cicero in his defcription of Syracufe. The mof 
elevated fituation, and commanding Tyche and Neapolis, it 
was judicioufly inclofed by Dionyfius 1. who furrounded tt 
with a wall of near four miles m extent. Its addifional de- 
fence was the fortrefs of Labdalon, at its bottom, on the eaft; 
and that of Euryalus, at its top, on the north f. 

The whole extent of the city of Syracufe, according te 
Strabo, whofe account is verified by the concurrent teftimony 
of Mr. Swinburne, was equal to twenty-two miles and four 
furlongs Englith meafure §, 

To this brief defcription of the principal divifions of this 
famous city, it is neceflary to add a few remarks relative to 
its immediate vicinage, and the waters by which ig i is fur+ 
rounded. : 

The Great Harbour, or Port, is about five miles in cir- 
cumference, and forms, at its north-weftern extremity, the 


* Cicero. Rollin. De Non. Swinburne, 
4* Cicero. Rollin. De Non. Swinburne. 
t Rollin, Swinburme. De Non, 

§ Swinburne, Vol. II. p. 309: 


Gulf 


248 On the Peftilential Difeafes which 


Gulf of Dafcon. Lower down, and oppofite to Ortygia, it 
is contracted. by the promontory and fort of Plemmyrium. 
The Little Port, or Portus Marmoreus, divides Ortygia from 
the Continent on the eaft, and wafhes the fouthern wall of 
Achradina. The Bay of Thap/us runs up behind Achradina 
on the eaft, and forms, by the junction of its weflern extre- 
anety with the city, the Port of Trogilus *. 

At the diftanee of about two miles from iyi and 
fomewhat lefs than a mile and a half from Neapolis, (whofe 
weftern wall crofled the low grounds through which it runs,) 
the river Anapus empties into the great harbour. This fiream, 
which is only twenty-four feet wide, and twelve or fifteen 
deep at its mouth, flows, in a ferpentine courfe, through a 
fmall extent of country, which, though flightly elevated on 
its fonth or fonth-weftern fide, esta north and north-weft 
confitts of an extenfive marfhy plain +. 

Between the Anapus and the promontory of Pilchtanyistil 


was fituated the little fuburb of Olympia, furrounding the - 


feite of the ancient temple of Jupiter Olympus, built upon 
an eminence, and bounded on either fide by the vaft Lyfi- 
melian marfhes, extending from the head of the great har- 
bour, half covered with water in the vernal months, and ex- 
haling, under a vertical fun, the moft unwholefome and. per= 
nicious vapours f. 

The preceding detail, it is hoped, will neither be found al. 
together tirefome, nor foreign to the purpofe of this effay. 
. Some part of it might, indeed, have been omitted, as not 
directly effential to the main defign of the paper; but there 
would have been lefs unity in the defeription, and fome por- 
tion of the fubfequent narration might have been lefs perfectly 
comprehended, 


* Aah al Swinburne. De Non, 

+ Roilin. Swinburne. De Non. ~ Thucydides, B..vi- and vii. 

+ Rollip. De Non. Swinburne. Watkin’s Travels, Letter xxiv. 

The reader will find great affiftance in comprehending diftinélly every 
part of the preceding defcription, from confulting the plan of Syracufe in 
Rollin’s Ancient Hifory, og that in his Roman Hiftory, which, though 
inaccurate jn fome refpects, 1 have reafon to believe the moft correét. 


rine 


\ 


= * 
appeared in the Neighbourhood of Syracufé. 2.49 


_ Secr. I1.—The peftilential difeafes prevailing m the 
neighbourhood of Syracufe, to which the prefent inquiry 
is limited, occurred at three diftirét periods: at the three 
fieges of that city, by the Athenians and their allies, under 
Nicias ; by the Carthaginians, under Imilcon; and by the 
Romans, under Marcellus. It is exccedingly to be regretted, 
that, confidering the fingular mortality which diftinguifhed 
‘each of thefe plagues, the information concerning them is 
fo feanty and general. But the precifion which remarkably 
charaéterifes that which remains, renders it of fufficient im- 
portance to deferve particular attention. It is the purpofe of 
the prefent Section to place before the reader, in a fuccinét 
narration, the circumftances which the hiftorians have pre- 
ferved relative to each of thefe interefting events. 

In the fecond year of the famous conteft between the Sy- 
racufans and the Athenians, of which Thucydides has left fo 
minute and ‘fo touching an account, the Athenians, whofe 
principal encampments were on the eaft of Syracufe—at 
Leon, at Thapfus,,at Labdalium, and on the port of Tro- 
gilus—undertook the conftruction of a wall, which extended 
to Epipole, ‘and was defigned, after crofling the plain and 
the marfhes of the Anapus, to reach to the great harbour on 
the weit, and inclofe the city. From the completion of this 
enterprife they were prevented by the exertions of the Syra~ 
cufans, who carried a divifion-wall from the city acrofs the 
marih, and thus oppofed an infurmountable barrier to the 
progrefs of their befiegers. To promote his defign, of the 
fuccefs of which he now began to entertain doubts, and to 
enable him more effectually to annoy the enemy by water, 
the Athenian general fortified and tranfported his army to 
Plemmyrium. From this time the fortune of the Athenians 
changed: their fatigue was great and inceffant; every trifl« 
ing fuccefs was fucceeded by fome fad revyerfe; relief was 
diftant and uncertain; and they became a prey to defpond- 
ency, not a little heightened by a fenfe of the injuftice of 
their caufe, their exemplary humiliation, and the unexpected 
fuperiority of their antagonifts. Under thefe circumftances, 
in the autumnal feafon, and “ encamped on marfhy and 

eWVor. V. kk unwhole- 


e 

450 On the Pefilential Difeafes which 
unwholefome ground *,” a fituation “ always unhealthy for 
an army, and Bleetally' in this feafon of the year f)"""a pef-" 
tilential difeafe fhewed itfelf in the camp, extending with the 
progrefs of the feafon, and the continued expofure of the fol- 
diery, or, as Plutarch expreffes himfelf, by contagion; till, 
haraffed by the enemy on one part, and worn down by fa- 
tigue and ficknefs on the other, the Athenians were driven 
to the fad neceflity of attempting a forced and fecret retreat, 
with the dereliction of their camp, their wounded, and their 


fick. The confummate eloquence of Thucydides alone is . 


adequate to the defcri iption of this fcene of hotvors: 


Of the numbers whe erithed by this peftilence, and of its, 
P P > 


particular fymptoms, no record is tranfmitted down to us 
The event of this fiege is known. The Athenians were fur- 
rounded on their retreat, and defeated with immenfe deftruc- 
tion, and under the mofi melancholy circumftances of dif- 
trefs: their general, worthy of a better fate, was cruelly put 
to death; and the greater part of thofe who were made pri- 
foners perifhed in Syracufe, the victims of difeafes induced 
by exceffive labour and unwholefome food. A few (in fuch 
honour was poefy among the ancients,) were emancipated by 
the recollection and recitation of even a fingle verfe of the 
pathetic tragedies of Euripides f. 

At a fubfequent period, and during the war between the 
Carthaginians and Dionyfius the elder, Himilco, or Imilcon, 
after al fuccefsful enterprifes in other parts of Sicily, 
marched againft Syracufe. He invaded it with an army of 
300,060 foot and 3000 horfe; while the Carthaginian fleet, 
of 200 fhips, under the command of Mago, followed by 500 
barks, entered the great port in a triumphal manner, and 
laden with the fpoils of the ravaged cities of the ifland. Imil~ 
con pitched his tent in the very temple of Jupiter, then 
ftanding at Olympia; and his army encamped around him. 


* Smith’s Thueydides, Vol. ET. p. 236. + } 
+, Piutarch, art, Nicias. 
+, f614.— For the particular hiftory of the fiege of Syracufe, the reader. 
ig referred, generally, to Thucydides, B. vi. and vii.; and to the Life of 
Nicias, by Plutareh. citing 
In 


, 


ae 


appeared in the Neighbourhood of Syracufe. _ .251 


In this fituation, “ an eminence between two morafies, 
highly favourable for a camp, and for rendering it impreg- 
nable,”’ he continued thirty days, laying wafte the country 
on all fides, plundering the temples, and demolifhing, the | 
tombs of the kings, and in vain offering battle to the Sy- 
racufans, who had not the courage to attack or oppofe him. 
Nature, more powerful than themfelves, arrefted the progrefs 
of that fate which threatened to overwhelm them. ‘¢ It was 
now in the mid{ft of fummer, and the heat this year was ex- 
ceffive.’ While Imilcon continued at Olympia, {preading 
devaftation around him, and anticipated a fignal revenge upon 
the hoftile Syracufans, a peftilential malady thewed itlelf in 
his camp. It appeared firft among his auxiliaries, the Afri- 
cans, who, forced into the fervice by fear of the Carthagi- 
nians, whom they hated, were probably leaft carefully ac- 
commodated. From them it foon extended, by the increaf- 
ing virulence and activity of the exciting canfe, throughout 
the army. Neither care nor medicine afforded relief. At 
firft the fick received fome affiftance from the well; but the 
peftilence and the mortality multiplied themfelves fo rapidly 
in every dire&ticn that this foon became mmpoffible, ror 
were there men to be found for the performance of the rites 
of fepulture to the accumulating dead. ‘* Violent dyfente- 
ries, raging fevers, burning entrails, and acute pains in every . 
part of the body,’’ were the ufual fymptoms of this terrible 
difeafe. Some were even feized with madnefs, and in their 
phrenfy attacked and endeavoured to deftroy all that were 
expofed to their affaults. Meantime the Syracufans, in health 
and fafety in their elevated, dry, and airy city, watched the 
progres of the peftilence among their enemies, and, profiting 
by their forlorn condition, captured or involved in flames their 
mighty fleet; and, ftorming their camp, impregnable to the 
gr eatclt force when defined by even a {mall body of healthy 
troops, defeated them with exemplary deftraGion. “Thus 
befet, enfeebled by difeafe and humbled by defeat, the proud 
Imilcon, who, a fhort time before, held the conqueft, not 
only of Syracufe, but of Sicily, too cheap and eafy a victory 
for fo formidable an hoft, was reduced to purchafe his fafety 


Kk 2 for 


252 On the Peflilential Difeafes which 


for 300 talents, and fled, leaving unburied the carcafes of 
150,000 of his foldiery *. 

The hiftory of the latt of thofe peftilential difeafes, whieh 
are particularly felected for prefent confideration, deferves a 
longer and more attentive examination. Furnifhing excel- 
Jent illuftration of feveral important points in the hiftory of 
thefe diforders, the reader will doubtlefs excufe fuch preli- 
minary narration as may conduce to place it more fully be- 
fore him, 

The Roman army, under the command of Marcellus, de- 
camped from their ftation at Leontium, the modern Lentini, 
and, arriving at Syracufe, encamped at Olympia. After an 
unfuccefsful attenipt at negociation, thé city was befieged in 
due form; and the attack commenced on Hexapylon by 
Jand, and on Achradina by water. ‘But the Roman general 
was not fuccefsful at Syracufe, as he had been at Leontium: 
all his exertions were rendered nugatory by the talents of a 
fingle citizen; and the genius of Archimedes triumphed over 
the power of Rome, ; 


» * Rollin’s Ancient. Hiftory, Vol. I. p. 302,30 , 04 ~ De Non’s Tra- 
vels, p. 358,359, &c, Diodorus Siculus, Lib. xiv. p. 279—295- 

The Carthaginians feem to have been deftined to owe the defeat of 
many of their moft promifing enterprifes in Sicily to peftilential difeafes, 
Tp a former part of the fame war, whofe unhappy termination has been 


defcribed above, Hannibal, the predeceffor of Imilcon, laid fiege to the. | 


city of Agrigentum (Girgentj), in the fouth-weftern part of Sicily. For 
the purpofe of raifing a wall wirhout, which fhould overlook and command 
the city walls, he colleéted all rhe materials within bis reach, and, among 
the rcft, deftroyed, and ‘converted to this ufe, the tomhs ftanding round a 
city very ancient and | populos, and then containing 200,000 inhabitants. 
From the uncovering and difturbing of fo many dead bodies arofe a ter- 
rible peftilence, which carried off immenfe numbers of the Carthaginians, 
and the general himfelf. Aflicted at this dreadful mortality, the befieg- 
ers attributed it, with the fuperftition of the age, to the vengeance of,the 
gods, incenfed againft them for violating the repofe of the dead. The 


healthinefs of the fitu: ation, the feafon, and the thorough appointment and 


fupplics of the Carthagiman army, leave no room to doubt as to the real 
caufe of the ficknefe, which gradually es a but two remarks, of 
fome importance, are fulygefted by it. . The folly of modern nations, 
efpecially i in warm climates, in fuifering et interment of the dead within 
their cities, 2. Phe w itdom of fome ancient nations, in having a déad, as 
well asa living town. 


_ Neceflitated 


dt 


| 


q 
Z 


appeared in the Neighbourhood of Syracufe. 253 


Neceffitated to defer the further operations of the ficge, the 
conful directed his arms againfl feveral other Sicilian cities, 


and ftruck his enemies with terror by his brilhant achieve- 


ments. About the fame time the Carthaginian gencral, 


- Himilco, arrived at Agrigentum, to the aid of the Sicilians, 


with an army’of 25,000 foot, 3000 horfe, and twelve cle- 
phants. Hippocrates, one of the Syracufan Icaders, with a 
part of the Syracufan troops, marched out to. meet him; 
Epicides having been left, with the remainder, for the de- 

fence of the city. After fome fhirmifhes with the Sicilian 
army, in which he was fortunate, Marcellus returned to 
Syracufe, whither he was foon followed by Himilco and 
Hippocrates, who, having formed a junction, fixed their 
camp at the river Anapus, about eight miles from the city. 
Nothing of importance occurred while the armies lay near 
each other. ~The combined chiefs foon drew off their forces; 
the Carthaginian general took up his winter refidence at 
Agrigentum, and the Sicilian at Murgantia. Marcellus, 
who had been for fome time bufied in the interior, now 
again returning, appointed Crifpinus to the command of the 
ancient camp at Olympia, and built and fortified a camp at 
Leon, on the eaftern fide of Syracufe, for himfelf, SL 

The Romans commenced their operations early in the 
fpring. Some of them having gained an entrance into Sy- 
racufe in the night, by ftratagem, the gate at Hexapylon was 
broken open, and Marcellus entering, fecured pofieffion of 
Epipole before any eflectual refiitance could be attempted 
by Epicides. Tyche and Neapolis furrendered at diferetion ; 
the fortrefs of Euryalus fpecdily fubmitted ; and the conful 
Gifpofed this part of his army againft Achradina, in three 
places, hoping to carry it by attack, or fubdae it by famine. 

+ While thefe preparations were going forward on the part 
of the Romans, Himilco and Hijpottates fuddenly returned 
to Syracute, and encamped on the great harbour. Frona 
hence they attacked C rifpinus in he ancient camp of the 
~ Romans, while Enicides, in concert, fallied out from the city 
upon the pofis of Marcellus. Neither of thefe affaults fuc- 
sine Crifpinus repulfed the allies, and purfued them wi- 
4 umphantly 


45>" On the Peftiiential Diep which 


umphantly to their ftation, at the fame time that Mawes 
compelled Epicides to take refuge within the walls of Achra- 
dina. After this, both of the Roman commanders flrength~ 
ened their encampments. > 

Such was the progrefs and ftate of the war when a pefti- 
lence, common to both armies, appeared both in the camp 
of the allies and of Crifpinus, and naturally diverted their 

ttention from hoftile operations: for the autamna! feafon, 
their unhealthy fituation, and the heat, (much more intole- 
‘rable without than in the city,) affected almoft every perfon 
in ether camp. At firft they became fick, and died, fimply 
from the effects of the feafon and the unhealthinefs of their 
fituation: afterwards, fays the hiftorian, the care and contact 
of the fick fpread the difeafe ; fo that thofe who were attacked 
with it perifhed, neglected and foriaken, or their attendants 
fell vigtims to their humanity. Deaths and funerals paifled 
before the view in rapid fucceffion, and day and night re- 
founded with lamentations. At length thefe feenes of cala- 
mity became fo familiar, that they not only neither wept, 
nor lamented the dead, but even ceafed to remove, or yet to 
inter them. Their lifelefs bodies lay extended in heaps, in 


the very fight of thofe who expected a fimilar fate; while -— 


“he dead infeed the fick, and the fick thefe who were in 


health, as well with fear as with the corruption and peflife-> 


rous exhalations from the bodies: fo that, impatient of life, 
and defirous rather to fall by the fword, fome fingly invaded 
the ftations of the enemy. The plague raged with far greater 


violence in the Carthaginien than in the Roman camp; for 7 


the Romans, from long refidence in the vicinity of syracufe, 


had become accuftomed to the air and water. As foon as — 


the Sicilian auxiliaries of the Carthaginians perceived that 


the difeafe fpread from the infalubrity of the place, they’ 
betook themfelves to their neare(i citics; but the. Carthagi. — 


nians, admitted into no city, together with their generals, — 


Himilco and Hippocrates, totally perithed. Marcellus, ob- 


ferving how faft the diforder increafed, drew the remainde ~ 


of his troops into the city, where, under fhelter, and in the 


fhade of the houfes, they regained health and vigour, note - 


withftanding 


y 


"ip 


‘ 


- 
> 


, 


"4 


appeared in the Neighbourhood of Syracufe. 255 


withftanding many of the Roman army were carried off by 
the fame peftilence *. 

Thus the Lyfimilian marfhes triumphed over a third army; 
and a number not lefs than 30,000 were added to thofe who 
had fallen of the foldiery of Nicias and of Imilcon. The 
practical confideration of thefe events belongs to the fuc- 
eeeding Section. 


Seer. I1I.—The fimplicity and uniformity of the preced- 
ing ftatements and narrative, preclude the neceffity for labo- 
rious inyeftigation and argument. The deductions to be made 
are unavoidably fimple and uniform; but their force and 
tendency may be more diftinétly perceived from a methodi- 
cal arrangement. 

1. Climate and feafon.—The climate of Sicily in general, 
and particularly of the city of Syracufe, is remarkably plea- 
fant during a confiderable part of the year. But the fummers 
are exceflively fultry; and this heat, operating on marfhy fitu- 
ations and ftagnant waters, never fails to engender malig- 


nant fevers. To thefe they are peculiarly liable m the fum- 


° 


mer and autumnal months, The peftilential difeafes which 
proved fo fatal to the armies of Nicias and Imilcon, and to 
thofe of the Carthaginians and the Romans, occurred either 
in the autumn or in the height of fammer; and, in every 
inftance, in the immediate vicinity of Syracufe. » 

- 2. Situation.—The camp of Nicias was near or at Plem- 
myrium ; of Imilcon, at Olympia; of Crifpinus, at Olympia 
alfo; and of Himilco and Hippocrates, at the head of the 
great harbour. The whole of this territory is a vaft marth, 


~ but partially covered with water even in fpring, extremely 
. offenfive in fummer, and noted, from time immemorial, for 


its infalubrity. 


 « 3. Condition of the armies.—The Athenian army was 
iw conftant action, and conftantly unfuccefsful. The army 


mee ore 


of Imilcon was in perpetual movement, but fortunate, and 
fall of courage. The adverfe armies, at the third fiege, were 


- ima ftate of inaGion. Thele are certainly confiderable dif- 


4 


ah: 


: * Tit. Liv. typis Barbore, 1775. Tom. III. Lib. xxiv, & xxv. p. 393 
‘ 


403. 
> ferences ; 


256 On the Peflilential Difeafes which 


ferences : : why fhould they not modify the event? It may be 
doubted whether any ‘moral caufe would be fufficient to pro 
tect, for a long period, an unaccuftomed refident in a marfhy 
fituation from the ufual confequences. Fatigue and defpon- 
dency are certainly favourable to the accefs of difeafe; and 
maction, particularly i in camps, is generally admitted to be 
fearcely lefs fo. The uncommon heat of the year of Imil- 
con’s irruption into Sicily, may be a fatisfactory explanation 
why his fuccefsful troops were fo readily diccied by the un- 
wholefomenefs of his camp. 

4.' Progrefs of the difeafe——The fick, in the army of 
Nicias, were not numerous at firft, but the number gradually 
imeregfed, This ts attributed, by Plutarch, to contagion ; 
but Thucydides, a cotemporary and. more fagacious hifto- 
rian, exprefies no fuch opinion, nor does it feem probable. 
The growing defperation of the Athenian, affairs, and the 
tendleney) of ‘the feafon to augment the extent and heighten 
the virulence of marth echulationes fufficiently account for 
the increafing_predifpofition to ficknefs, and for its more ge- 
neral prevalence in their army. 

The fame reafoning will apply, generally, to the cafe of 
Imilcon’s army ; butt: there were, in this inftance, additional 
caufes for the produdtion of fuch immenfe mortality. The 
commencement of this peftilence was among his African 
auxiliaries.” The circumftances of their impreffinent into the 
fervice, and of the contempt in which they were held by the 
Carthaginians, render it probable that lefs care was taken to” 
accommodate them than the others, Some peculiar habits 
of body, modes of life, or varieties of native climate, might 
influence this event; or they might have been previoufly 
fubjected to greater fatigue. Be this as it may, the ficknefs 
foon became univerfal, and fo mortal that the dead lay un- 
buried. Ina fituation lke this, there is no reafon to believe 
that much attention was at any time paid to the neceflary 
duties of cleanlinefs. When the fick could find ne attend- 
ants, and the dead none to inter them, it requires but little 


faracity to infer that no means were. uled for the removal of 


excrementitious matters, And as a large proportion of this 


army were afllicled with dylentery, and thy number cf pu- 


8 tre! ying 


ee 


appeared in the Neighbourhood of Syracufe. 257 


trefying carcafes muft have been immenfe, and as the limits 
of the camp were not very exténfive, and they were now 
forely preffed by a vigorous enemy, incapable themfelves of 
refiftance, and fuddenly precipitated from triumph to inevit- 
able defeat and fhame, we fhal! find no difficulty in affigning 
caufes fufficient and ey for the extraordinary fatality 
of this peftilence. 

The third plague commenced at the fame time in both the 
Carthaginian and Roman camps. At firft; as in the former 
inftancé, the fick were attended to; but the number foon 
became fo great as to render this impoffible. In this cafe, 
as in the other, the dead were left unburied, and to putrefy ; 
and in this cafe, as in that, there is no reafon to doubt but 
that the caufes and fatality of the difeafes were in confe- 
quence excecdingly augmented. It may reafonably be 
doubted, however, whether’ the hiftorian is accurate in 
Werbinn any part of the fpread of the peftilence to contas 
of the fick. The belief of this doctrine has been of long 
duration and extenfive prevalence; but late obfervations do 
not feem to countenance its validity. To eftablith it, would 
inevitably annihilate a diftinétion much infifted on by the 
advocates for the importation of peftilential difeafes into the 
United States; but this argument is not wanted for that 
purpofe. It is more probable that the peftilence, in this in- 
ftance, as in that preceding, was rendered more general by 
the increafing quantity and concentration of marth effluyia ; 
by the excrementitious matters in the camps, fuffered to 
affume, unremoved, a putfefcent, action; and by noxious 
exhalations from putrefying bodies. There are ng facts 
which authorife the opinion that a fpecific matter emanates 
from any part of the body; during peftilential or any other _ 
fevers properly fo called, capable of generating a fimilar or 
a febrile difeafe. The moft that we may venture to infer 
from all the fasts known to us, is, that the perfpirable mat- 
ter, like any other animal fubftance, when feparated from 
the living body, or deprived of life, is liable, under certain 
circumftan@es of temperature and moilture, to undergo a 
putrefactive fermentation, or to go through fuch changes as 
fhall adapt it for the production of febrile difeafes; and this, 

Wot. V. EY ay as 


458 On the Peftilential Difeafes which 


as well when fuffered to lie on the fkin, as when elfewhere, 
or otherwife difpofed of. With thefe limitations, and in 


this view of the queftion, there need be no objection to the, 


teftimony of Livy; nor have we any ground, from a know- 
ledee of the fymptoms of the plague he defcribes, to oppofe 
or fortify his narration. 
5. Mortality of the peftilence.—Of the mortality of the 
ficknefs which affected the army under Nicias, we only 
‘know that it was confiderable. Our knowledge is not much 
more definite -refpecting the number of the Carthaginians 
who perifhed of the army of Imilcon. There is reafon, how- 
. ever, to believe that it far exceeded that of the Athenians, 
and probably it was not lefs than 100,000 men. For it muft 
be recollected, that many had been regularly interred in the 
firft of the plague, and that all the fick and wounded were 
_left behind when their general ingtorioufly fled from Sicily. 
Nor is it probable that a number greatly exceeding 50,000 
fell in the battle which. preceded his flight. In the laft cafe, 
our computation may be nearer the truth. The army with 
which Himileo invaded Syracufe amounted to 28,000, ex- 
clufive of his Sicilian auxiliaries, and of the troops from that 
city which joined him under the command of Hippocrates. 
The defeat of this laft, by Marcellus, the preceding year; 
the feceffion of the Sicilians; and his own loffes in the va- 
rious ations in which he had been previoufly engaged, had 
no doybt reduced his army below its original ftrength. But, 
when it is remembered that all this army perifhed, and that 
a lefs, but ftill a great number of the Roman army alfo were 
deftroyed by the plague, there is reafon to eftimate the whole 
lofs as exceeding 30,000, The entire number of men fa- 
crificed to this unhealthy fituation, in three fucceffive periods, 
- could not be lefs than 150,000: a moft melancholy illuftra- 
tion of the influence of climate, feafon, and foil, on the health 
of mankind; and an example of the aétivity of local caufes 
in producing difeafe, compared with which, all the yellow 
fevers of the United States, whether originating here, or im- 
ported from abroad, fearcely deferve to be remembered. 
6. Symptoms and natute of the peftilence.—On_ this 
point our information is lefs complete than. on any other. 


9 >) The - 


v%¥ 


appeared in the Neighbourhood of Syracufe. 259 


The ficknefs iti the Athenian army is fimply called a fever, 
faid to be contagious by Plutarch, but probably not fo. Livy 
defcribes no fymptoms of the plague recorded by him. Dio- 
dorts Siculus is fomewhat more particular; but only fo far 
as to mark the variety of form in which the feldiers of Imil- 
con were attacked by the difeafe. In fome, in the fhape of 
enteritis, or inflammation of the bowels; in others, of dyfen- 
tery, fometimes invading as a violent fever, with acute pains 
in every part of the body, and fometimes with madnefs or 
delirium. Yet, even thefe fcanty particulars are of import- 
ance, as they ferve to identify the difeafe, and to proclaim its 
ftri&. affinity to thofe which are the common offspring of 
fuch fituations as that in which the army avere encamped, 
‘and thofe which have fpread fo much apprehenfion, and ex- 

cited fo. much difcuffien in our own country. 
7. Ceflation of the peftilence.—Another circumftance 
which chara¢terifes the difeafe under confideration, is the 
manner in which it was extinguifhed. So long as Nicias 
remained in his camp, he faw his men conftantly dying 
around him by ficknefs. His removal, notwithftanding the 
fubfequent calamities which befel him, appears to have tho- 
roughly delivered his army from fevers. The furvivors were 
employed as {laves in Syracufe; which could fcarcely have 
happened had they been fick, or had the Syracufans dreaded _ 
the introduction of a contagious difeafe by their means.— 
Imilcon preferved the refidue of his army only by flight : there 
was no other hope for their fafety; and, after his return to 
Carthage, he exclaimed, in the bitternefs of his grief, that the 
plague, not the enemy, had conquered him! But neither 
then nor before did the dry and airy city of Syracufe fuffer 
from any ficknefs; nor did the fear of contagion prevent the 
Syracufans from repeatedly attacking the Athenian and Car- 
thaginian camps. ‘Their minds were probably unwarped by 
the bias of fyftem; and they difcerned, in the pofition of their 
enemies, the true caufe of their misfortunes. —The fads re- 
lated by Livy are fingularly precife and important. In the 
 firft place, neither the citizens of Syracufe, nor the army of 
Epicides, which had pofleffion of Ortygia and Achradina, 
Lla ner 


"260 On Peflilential Difea/ss. 


nor that part of the Roman army which, under the command > 


of Marcellus, was ftationed in the elevated quarters of Tyche, 
Neapolis, and Epipole, were in the leaft affeéted by the 
plague. But this calamity was limited to the Romans under 
Crifpinus, in the ancient camp at Olympia; and to the allies, 
who were encamped at the head of the great port. Crifpinus 
and his troops, who had lived at Olympia a confiderable part 
of the two preceding years, or at leaft had remained in the 
vicinity of Syracufe, and had become in a degree habitu- 
ated to the air and water, fuffered lefs’ feverely than their 
enemies; and, when the ficknefs became general among 
them, recruited, and ceafed to be taken fick, in confequence 
of a removal to the high grounds of thé-city, occupied by 
their countrymen. The natives of the ifland, feeing the 
danger to which they were expofed, took refuge in their own 
cities, and efeaped the difeafe; but the Carthaginians, with- 
out any place of refuge, and entirely unaccuftomed to their 
fituation, totally perifhed. 

8. On the whole, then, it appears that the mortality, in 
every ipftance, occurring in the armies near Syracufe, ori- 
ginated entirely from local caufes: that there is no reafon to 
fufpe&t that this mortality was heightened by contagion, in 
the ufual acceptation of that term: that the fymptoms, fo far 
as we have any account of them, were fimilar to thofe which 
occur, under fimilar circumftances, in the Eaft and Weft 
Indies, in our own country, and in every part of the world: 
and that, as no difference is recorded as-exifting between thefe 
great epidemics or endemics before:and after the caufes were 
increafed by animal putrefaction, the advocates for the foreign 
derivation of peftilential difeafes muft relinquith the diftinétion 
between fevers from animal and vegetable putrefaction; or, 
if they maintain the contagious quality of the former, muft 
admit, ‘on equal evidence, the fame quality as characterifing 
the latter. To this it may be added, that,.as it was the uni- 
verfal practice of the ancients to defignate any and every 
wide-wafling difeafe by the name of plague, without any 


fpecial reference to its peculiar fymptoms, fo there is an’ 


equal propriety in our conferring the fame appellation on 
Bc aa ; | . our 


q 
} 
‘ 
j 
q 


On Scowering different Kinds of Stuff. abt 


- our. dyfenteries and fevers; nor do thefe lefs deferve the 


title than the fevers of Smyrna, Cairo, and Conftantinople, 
which refemble them in their origin, their varieties of pre- 
valence and degree, their appearance and difappearance, and 
which would, in all probability, yield to the fame regimen 
and iencdies. 


= 


VIII. Objervations on the Art of Scowering different Kinds 
of Stuff. By C. CHAPTAL%. 


Tus art fuppofes, rft, a knowledge of the different fub- 
ftances capable of ftaining any kind of cloth; ad, of the 


- fubftances to which recourfe mutt be had in order to make 


thofe depofited on the fiuff to difappear ; 3d, a knowledge: 


_ of the effects produced on colours by thofe re-agents which 


it may be neceflary to employ to deftroy flains ; 4th, a know- 


ledge of the manner in which the cloth is affected by thofe 
re-agents; 5th, of the art of reftoring a colour changed of 
faded.—Of thofe bodies which occafion fpots on different 
kinds of cloth, fome are eafily diftinguifhed by their appear- 
ance, fuch as greafy fubftances ; but others have more com- 


plex effects, fuch as acids, alkalies, perfpired matter, fruits, 


urine,.&c, Acids redden black, fawn, violet and puce- 
colour, and every fhade communicated with orchilla-weed, 
iron, aftringents, and every blue except indigo and pruffian 


blue. They render the yellows paler, except that of arnatto, 


which they change into orange. 
Alkalies change to violet the reds produced by Brazil wood, 


logwood, and cochineal. They render the greens on woollen 
‘cloth yellowith, make yellow brownith, and change the yel- 


; Jow produced by arnatto to aurora. Perfpired matter produces 
the fame effects as alkalies. 


When the {pots are produced by fimple bodies on ftuffs, 
it is ealy to remoye them by the means already known. 
Greafy fubftances are removed by alkalies, foaps, the yolk of 


eggs, fat earths; oxyds of iron, by the nitric and oxalic acids; 


_ acids by alkalies, and reciprocally. Stains of fruit on sahite 


* From the Bulletin des Sciences, Vol. LI. No, 4. 
ftufls 


62 Odbfervations on the Art of 


ftuffs may be removed by the fulphurous acid, and fill better 
by the oxygenated muriatic acid, But when the {pots are of 
a complex kind, it will be neceffary to employ feveral means 
in fucceffion. Thus: to deftroy the ftain of coom from car- 
riage-wheels, after the greafe has been diffolved the oxyd of 
iron may be removed by the oxalic: acid. R 

As colours are, often changed by re- agents, it will be ne- 
ecflary, in order to reftore them, that “the fcowerer fhould 
poflefs a thorough knowledge of the art of dyeing, and 
how to modify the means according to circumftances. This 
becomes the more difficult when it is neceflary to re-produce 
a colour fimilar to that of the reft of the fluff, to apply that 
colour only in one place, and often to refiore the mordant by 


Ce 


which it was fixed, and which has been deftroyed, or even. 


the firft tint which gave the colour its intenfity. It may be 
readily conceived that the means to be employed muft depend 
on the nature of the colour and the ingredients by which it 
was produced ; for it is known that the fame colour may be 
obtained from very different bodies. Thus, after an alkali has 
been employed to deftroy an acid fpot on browns, violets, 
blues, poppies, &c. the yellow fpot which remains may be 
made to difappear by a folution of tin ; afolution of fulphat 


of iron reftores the colour to brown ftuffs which have been -— 


ealled'; acids reftore to their former fplendour yellows which 
have been rendered dufky or brown by alkalies; blacks pro- 
duced by logwood become red by acids; alkalies change 
thefe red fpots to yellow, and a little of the aftringent prin- 


ciple makes them again become black. A folution of one ~ 


part of indigo in four parts of fulphuric acid, diluted with a 
fufficient quantity of water, may be employed with fuccefs to 
revive the blue colour of cotton or wool which has been 


changed. Scarlet may be revived by means of cochineal 


and a folution of the muriat of tin, &e. 

The choice of re-agents is not a matter of indifference. 
Vegetable acids are preferable; the fulphurous acid however 
may be employed for ftains occafioned by fruit: it does not 
change the blue of filk nor colours produced by aftringents : 
it does not degrade the yellow of cotton. A:nmonia fuceeeds 
better than fixed alkahes in removing fpots produced by a 


, 


: 


bay 
A 


] 


Scowering different Kinds of Stuff. 263 
- It is employed in vapour; its action is fpeedy, and feldom 
alters the colour. 
The means of removing greafy fpots are well known. 
_ This effeé& is produced by alkalies, fullers’ earth, volatile oils 
diffolved in alcohol, a heat proper for volatilizing greafe, &c. 
Spots occafioned by ink, ruft, or iron-mould of any kind, 
and ail thofe produced by the yellow oxyd of iron, are re- 
moyed by the oxalic acid: the colour may be reftored by al- 
kalies, or a folution of the muriat of tin. Thefe fpots may 
- be removed alfo by the oxygenated muriatic acid, when they 
_ are on white ftuffs or paper. 
» The aétion of alkalies, and that of perfpired matter, are 
the fame: their fpots may be effaced by acids, or even by a 
weak folution of the muriat of tin. When thefe fpots arife 
from feveral unknown caufes, i order to deftroy them re- 
courfe muft be had to polychreff compofitions. The following 
may be confidered as one of the moft efficacious. Diffolve 
white foap in alcohol, and mix this folution with the yolks 
of from four to fix eggs: add gradually effence of turpen- 
tine ; and incorporate with the whole fome fullers* earth, in 
fuch a manner as to form balls of a fuitable confiftence. 
Moiften the fpot; and, having rubbed it with thefe balls, 
‘the fpot will be removed by wafhing the ftuff. All fpots, 
except iron-mould and ink, may be removed in this manner. 
Wathing deftroys the luftre, and leaves a tarnithed place 
_difagreeable to the eye; but the luftre may be reftored by 
drawing over the wafhed place, and in the direction of the 
pile, a bruth moiftened in water impregnated with a little 
gum. ‘You may then apply a fheet of paper, or a piece of 
sloth, and a confiderable weight, under which the cloth muft 
_ be left to dry. 


IX. Defcrip- 


[ 264 J 


IX. Defcription of fome Improvements invented by Mr. James — 
Burns, of Glafgow, applicable to Fire-Grates, Stoves, 
&$c. by which Rooms and Halls of every Defcription may 
be heated more fpeedily and effectually, and with a Jmaller 
Wafte of Fuel, than by the Methods now in Uje*. . 


Tu E principal merit of Mr. Burns’s improvemenits, and 
it is not a trivial one, confifts in his contriving to maintain 
the combuflion of the fuel in open ftoves or grates, without 
employing for that purpofe the air of the room in which they 
are placed. The heat liberated and thrown out into the- 
apartment is thus prevented from being unneceflarily wafted 
and hurried up the chimney, as is unavoidably the cafe in 
the ufual method, where the combuftion is maintained by 
air from the apartment, the wafte of which is fupplied by 
exterior cold air that comes pouring in at the bottom of the 
doors and the fides of the windows, thereby undoing a great 
part of the effect produced by the fire. 

To prevent this wafte, the air that maintains the fire in 
Mr. Burns’s grates, or in others to which his improvements 
are applied, fhould be brought through a tube from the out- 
fide of the houfe ¢, or be made to pafs from the outfide of 
the houfe, between two of the joifts, where the floors and 
ceilings are found enough to allow this, fo as to be brought 
to the bottom bars of the grate, without having any commu- ~ 
nication with the interior air of the room, while at the fame 
time the grates, and parts conneéted with them, fhould be 
fo conftru@ted, that, when the fire is not wifhed to be fup- 
plied with cold air from the outfide of the houfe, the paffage 
may be fhut, more or lefs perfe€tly, by means of a valve, & — 
fmall door, a cock, or any fimilar contrivance. When con-— 
venience does not admit of the air-tube being carried to the 


* Mr. Burns has lately obtained a patent for thefe improvements. 

+ Tire fame principle had been already fuccefsfuily applied to clofe fur- 
naces: Mr. Howard’s, of which we gave an account in our faft Number, 
furnifhes an example. But its application to common open. fires is a new 
idea, and will probably produce an entire revolution in the conftruétion of | 


grates for cqammen uit. 
outiide — 


7 


Improvements upon Fire Grates, Sioves, &c. 265 


outfide of the houfe, if carried to a cellar, larder, ftair-cafe, 
or any lumber-room, the fame end will be gained; with this 
further advantage, that fuch cellar, larder, &c. will thereby 
be well ventilated, and prevented from acquiring or retaining 
any unhealthy or difagreeable {mells,’ 

The form of the grates may be varied indefinitely ; but the 
one we are about to defcribe anfwers the purpofe fo well, and 
is at the fame time capable of being made, by the aid of a 
good architect, fo highly ornamental to any apartment, that 
our readers will fully comprehend the facility with which it 
may be accommodated to cir@&mftances. 

Fig. 1, (fee Plate V & VI.) reprefents a grate of the improved 
conftruction, and Fig. 2 is a fection of it. The air that main- 
tains the combutftion is fupplied through the pipe or tube A, 
(Fig. 2 and Fig. 4,) or from between the under-ceiling and 
floor as before-mentioned, from which it pafles up. by the 
back or fide of a drawer B, Fig. 2, according as it is moft 
convenient to bring it up by the one or the other; the back 
however is preferred, where convenience admits of it. The 
front of this drawer, in its place, is feen in Fig. 1, at C. 
The intention of this drawer is to receive the afhes that fall 
from the bottom bars of the grate, feétions of which are 
reprefented at DD, Fig. 2. The afhes, as they fall from 
the bars, firike again{t the fides of the internal cavity E, 
and then are carried by their own gravity through the narrew 
part F, and fall into the drawer. This part of the con- 
firuction may be eafily underftood by conceiving it to be an 
hollow vafe, as it actually is, with a drawer in its pedeftal 
or bafement, and having a grate over it, on,which the fire 
refts. The valve, door, cock, or other contrivance by 
which the external air is admitted or excluded, may be 
either in the neck F of the vafe, or in the air-tube, or in 
the drawer B or C, or, which is preferable, in. the cavity, 


behind the drawer, the pedeftal or bafement of the vafe 


being made large enough to admit of fuch cavity. Various 
confiructions may be reforted to; but that reprefented in 
Fig. 3, (which is a ground-plan of a proper chimney for 
fuch a grate, and in which a bird’s-eye view of one half of: 


the grate may be feen in its place, while the other half repre- 


~ Vou. V. Mm fents 


466  Iniprovements upon Fire Grates, Stoves, &e. 


fents an horizontal fection of the bafement or pedeftal, 
which is fuppofed to be open, fhewing the drawer in its place, 
with the cavity behind it,) will be found to anfwer every pur- 
pofe. The cavity G is feparated from the place in which 
the drawer is put, by a partition (beft made of plate or caft- 
iron) pafling from H to H, in which there is an opening I, 
with a cover K. To the cover K is attached a fmall bar L, 
worked by another fhorter bar M, to whieh it is attached 
by any fimple joint. The bar M is faftened into an upright 
‘pivot, the top of which comes up through the pedeftal at 
one of its corners or any othér convenient fpot, and is fur~ 
iifhed with a button to be laid hold of by the fin ger and 
thumb, or with a top fitted to a key, by the turning if which 
the cover K is made to fhut or open the aperture I, and con- 
fequently to prevent or facilitate the paflage of the air from 
the hole at G, which reprefents the internal mouth of the. 
air-tube, the other end of which ts on the ouffide, of the 
houfe, or in any cellar or other apartment, as before de- 
fcribed. When the air has paffed through the aperture I, 
it finds no difficulty in pafling on to the bottom of the grate, 


that back or fide of the drawer next which the aperture is - 


being made Jow to allow it to flow m freely. 


The grates are recommended to be made of a circular or 
elliptical form, as beng moft convenient, where the fence or 


fereen, to be immediately defcribed, is wifhed to be apphed 
along with Mr. Burns’s other improvements. The fence is 
intended to prevent thofe dreadful accidents, which too fre- 
quently occur, of women’s and children’s clothes being fet 
on fire by fparks from the grate. When it is wifhed to be 
adopted, the infide of the chimney, where the grate is to 
ftand, had beft be a femi-cylmder, or nearly fo, (as repre- 
fented in Fig. 3,) with a lining or cover gaa, belt made 
of metal, at fuch a diftance from the femi-cylindrical wall, 
NNNN, as to give fufficient room for allowing the fafe- 
guard or fence to be flid round mto it when the fire is 
withed to be left open, when frefh fuel is ‘to be added, or 
when the drawer with the afhes is ta be removed, 

- The fence is a frame-work of metal, which, when filled 
ore with glafs of with wire-work, foci a portion of a cylin- 
der 


— ee 


: 
¥ 
. 


Improvements upon Fire Grates, Stoves, &c. 267 


der anfwerable to the curvature of the fpace between the 
back of the chimney and the lining above-mentioned, made 
in oné or more pieces, and moving in a circular groove, 
644, in or upon the hearth, which ferves to condué it into 
its place behind the grate, when the fire-place is wifhed to 
be left open, as before mentioned. The top of the front of 
the opening of the chimney O, Fig. 4, projects in a cir- 
cular form, or is furnifhed with an added projeétion, made 
of metal, marble, or any other fit material 3, but in either 
cafe the projection is furnifhed with a circular groove on its 
under furface, of the fame radius with the one in, or planted 
on the hearth, for the purpofe of receiving the upper part 
of the frame-work of the fence or fafeguard, which frame- 
work may be filled up with glafs, either plain or bent, and 
either colourlefs or. coloured, or ftained or painted with 
figures or defigns of any kind. By this means complete 
fafety is obtamed again{ft any fuch accidents as have been 
alluded to, while at the fame time the comfort arifing from 
the view of a cheerful fire is not prevented by the interpofi- 
tion of any opake body ; but for nurferies or the like, where 
convenience and fafety is more the obje&t than elegance or 
Juxury, the frame-work may be filled up with wire-work. 
The fence may be feen in its place at P. . 

Where either the glafs or the wire-work fence, or both of 
them, are meant to be applied to fquare or retangular chim- 
neys, without the trouble of giving them the femi-cylindrical 
form, the lining to receive the fence or fences may be intro- 
duced at the fides or jambs of fuch chimneys ; or the fence 
may be made to rife by means of pulleys into the wall above 
the opening, or flide fideways into the walls at the fides of the 
opening. 

Thefe improvements may be introduced together or fingly, 
and may be applied to many of the grates now in common 
ufe. 

Befides the advantages already pointed out as conneted 
with them, they poffefs alfo the following.—Any room or 
apartment may be heated by their means with a much 
fmaller quantity of fuel than by any other method yet in 
ufe: at the fame time the advantage of feeing the fire is not 

Mm 2 loft, 


268 On the Chemical Action of 


loft, as in ‘alle ftoves; for thefe grates have fide as well as 
bottom bars, which allow the paididiit heat and light to be 


thrown out into the room without any impediment: and in ~ 


fact large rooms, halls, and the like, which by the ufual me- 
thods can hardly be warmed, or made at al] comfortable in 
cold weather, may, by means of thefe improvements, be 
heated as effectually as the fmalleft apartment; for, when 
their full effect is wanted to be produced, it is only neceffary 
to keep the fence in its recefs, that even that portion of heat, 
which would be kept back by the interpofed glafs or wire- 
work, may be thrown out into the room, and perform its 
office. They are alfo an effectual cure for fmoky chimneys, 
which not only caufe great wafte and deftruétion of good 
furniture, but many difeafes to the inhabitants of houfes 
plagued with that evil. They caufe a clean fire-fide to be 
eafily commanded at all times, as hardly any of the daft or 
afhes fall through the fide bars, almoft the whole pafling 
through the bottom bars down into the drawer; and any 
fire lighted in fuch improved grates burns up and becomes 
lively in a few minutes, without the aid of bellows, and that 
watchful care which common grates or fioves require. 


X. On the Chemical A&ion of different Metals on each other 
at the common Temperature of the Atmofphere. By C. PaB- 
BRONI*. 


"Tat particular fenfation, firft made known by Sultzer, 
which is felt on the tongue on bringing two metals into mu- 
tual contact, and which would have excited none if they 
had been applicd feparately to that organ, has been ranked 
among the galvanic phenomena. C., Fabbroni, however, in+ 
ftead of siaene thefe effeéts to an agent almoft unknown, 
fuch as the aces fire, is of opinion that it depends on.a 
chemical operation, perhaps as the fenfation of tafte itfelf, 
He has endeavoured to prove the truth of this opimion by a 
number of obfervations and experiments, - 


© From Bxlictin des Sciences, Vol. 11, No. 5. 


He 


different Metals on each other, 269 


He had remarked that feveral metals, fuch as mercury, 
tin, lead, retained their metallic brilliancy as long as they 
were pure, while compounds of them became foon tarnifhed 
and oxydated ; that the mere contaét of two different metals 
feemed to haften their oxydation ; and that, in this manner, 
the mixture employed for foldering the plates of copper 
which cover the obfervatory of Florence, had been {peedily 
changed into a white oxyde at the outer edge of its contaét 
with the copper, &c. He thinks that, in this cafe, the metals 
have a reciprocal aCtion on each other; and that this action, 
more efficacious and more fenfible when the attration of ag- 
gregation of the metals is deftroyed by fufion, exifts no lefs 
between folid metals when they touch each other. 

If the effets, as rapid as thofe of lightning, occafioned on 
the tongue by two metals bronght into conta&, have been 
by fome afcribed to a peculiar fluid not galvanic, or to the 
eleGtric fluid, it is becaufe they did not recolle& that che- 
mical aétion Is exercifed between two bodies with the utmoft 
rapidity. The figns of eleétricity which have been fometimes 
obferyed on feparating two metals in contact, are rather the 
confequences than the caufe of that aétion; for it is known 
that the greater part of chemical operations change the elec- 
tric equilibrium of bodies, and muft confequently give birth 
to electrical phenomena. Without totally excluding elec- 
tricity, therefore, from all ealvante facts, C. Fabbroni thinks” 
that this fluid has fome fhare in the fenfation experienced 
by the tongue from two metals in contaét. This a@tion of 
metals in contact is proved by the following experiment :—~ 

C. Fabbroni put into two glaffes filled une water, pieces 
of different metals, one in each alts. In other glaffes he put 
two pieces of different metals, but kept them from touching 
by interpofine a plate of glafs. In a third feries of glaffes he 
alfo put two pieces of different metals, but in conta&. In 
the metals of the two firft feries he obferved no change, while 
the moft oxydable metals of the third feries were covered with 
an oxyde, which confiderably increafed in the courfe of a few 
days, and the metallic pieces even contracted. a ftrong ad 
herence. The quantity of the caloric which difengages itfelt 
in pthele combuftions is too finall to be meafured, yet the 

light 


270 Chemical A&ion of Metals on each other. 


light which emanates from it may be feen, if the eye itfelf 
forms a part of the experiment, by holding a piece of filver 
in the mouth, and applying a bit of tin to the ball of the eye. 
After thefe two metals are made to communicate, you fee a . 
feeble but diftin& light, which difappears at the end of a 
few feconds, becaufe the eye becomes accuftomed to this 
feeble fenfation ; but it may be renewed by drawing the 
metal over the opake cornea, and then over the tranfparent. 
The author afcribes to a convulfive fenfation that kind of 
flafh which fome perfons think they perceive * at the mo- 
ment of the contaét of thefe metals, applied one on the 
tongue, and the other under it. 

To make the oxydation of the two metals take place under 
water, the prefence of air is alfo neceflary. C. Fabbroni thinks 
that air is ufeful in this circumftance, to add to the water a 
fufficient quantity of oxygen to be taken up by the metal, as 
filver is added to gold in order to perform the operation of 
quartation. Ifa piece of filver and a piece of tin be put in 
contact in. water, inclofed in a flafk of flint-glafs hermeti- 
cally fealed, the tin is oxydated; but the oxyde of the lead of 
the flint-glafs is decompofed, and the glafs becomes black. 
Philofophers, who afcribe thefe phenomena to eleé¢tricity, - 
bring, as a proof of their opinion, that they take place when 
the metals are conne¢ted even by means of a pretty long 
chain. C, Fabbroni has determined the length of this chain ~ 
at about 18 or 20 feet. Beyond that diftance thefe pheno- 
mena are no longer fenfible; while, on the other hand, the 
electric fluid is communicated to indefinite diftances, . 

If the phenomena of the experiment of Sultzer belonged 
really to electricity, they ought to take place with all metals, 
whatever may be the relation of thefe metals to each other, 
C. Fabbroni mentions a great number of thefe combinations 
which produced no effects; and other combinations, of the 
dame metals, which produced fenfations very diftinét. Thus, 
if filver be placed on the eye, and gold on the tongue, making 
them communicate by means of copper, the fenfation is al- 
anoft nothing; but it-becomes very evident if the iron touches 


* The perception is as real as that induced by drawing the metal ovér 
the cornea of the eye. Enprr. ; 
i) the 


On the Art of Hardening Copper. 47% 
the eye, and the filver the tongue, the communication being 
eftablifhed as before with copper *. 

' In regard to the hydrogen of the decompofed water,’ the 
author thinks that it may alfo be abforbed by the metal: he 
even confiders as ari hydro-oxyde of tin, the o¢taedral cryftals 
which he remarked on the furfaces of the pieces of tin em- 
ployed in thefe experiments.—It is clearly feen, fays C. Fab- 
broni, by the refults which I obtained from the fimple con- 
taét of two metals in water, that is to fay, by the oxyde and 
faline cryftals, that a chemical operation takes place, and that 
to it we ought to afcribe the fenfations experienced on the 
tongue and by the eye. It appears to me, then, probable, 
that it is to thefe new compounds, or their elements, that we 
are indebted for that myfterious ftimulus which produces the 
convulfive movements of the animal fibre in a great part at 
leaft of the galvanic phenomena. 


XI. On the Art of Hardening Copper. By P.1. Hieum f. 


Corprn: in its pure and perfeé ftate, is exceedingly 
foft and malleable: its toughnefs is then fo great, that it is 
exceeded only by gold and iron. When copper is hammered 
a long time cold, and {till more when rolled, it is found, as 
is well known, fomewhat harder than before, but it does not 


- thereby acquire that ftrength which deferves the name of 


hardening, or which enables it to make fuffictent refiftance to 
{trong imprefiions. By being brought to a bright-red heat 
in the fire, and fuddenly quenched in water, copper obtains 
no perceptible addition to its hardnefs; but, on the contrary, 
becomes more pliable, and confequently fofter than before. 
If the copper is kept a long time in fufion, or often fufed in 
a {trong heat, without any covering of flux or charcoal pow- 
der, it becomes brittle and unmalleable, and confequently 


_ * This is no conclufive argument againft the effet being electrical ; 
it is taking for granted that the laws and properties of the eleétric fluid 


_ have all been afcertained. Epur, 


» + From Tian/udtions of the Ruyo! Acaiemy of Sciences at Stockholm for 
1797+ . é, 
ot. harder: 


£72 On the Art of Hardening Copper. 
harder: but thefe properties are foon loft when the copper is 
melted in contaét with carbonaceous matter. If melted cop- 
per be poured into water, as is done in the operation of gra- 
nulating or corning g, it does not appear that it acquires any 
perceptible degree ‘of hardnefs, or fuch as can be compared 
to that which is communicated to fteel by the fame means. 

Confidering all thefe circumftances, which have been con- 
firmed by experience, it could not but excite attention to 
find, by the moft undoubted teftimony, that the ancients 
actually poffeffed the art of hardening copper, which they 
employed for inftruments of all kinds; fuch as daggers, 
fwords, bows, fhields, javelins, &c. Thong ancient au- 
thors often mention thefe weapons, none of them have given 
us.any account of the method of hardening the copper. This 
deficiency fome have attempted to fupply by conjectures, 
which have given rife to a variety of experiments, but not 
one of them was ever attended with fuccefs. As it was 
imagined that in hardening copper it would be neceffary to 
follow the fame procefs as that employed for. fieelifying 
iron, moft of their refearches have been direéted to a fimilar 
method; and for that purpofe they have not only preferibed, 
for the hardening of copper, fuch procefies as are employed for 
hardening iron when it is to be converted into fteel, but even’ 
the moft abfurd methods founded upon thefe procefies. Thefe 
refearches, however, inftead cf anfwering the intended pur- 
pofe, only tend to fhew the ignorance of thofe who think 
they find in the greateft abfurdity the moft important fecrets, 
and to involve us in ftill greater darknefs. 

The art of hardening copper has therefore of late been 
’ confidered as one of thofe known to the ancients, which were 
afterwards loft; and it would no doubt have ftill remained in 
that ftate, had not feveral of thefe monuments of our ancef- 


tors been brought to light by fome fortunate accidents, and- 


the refpeét for their great antiquity been overcome by a defire 
for becoming acquainted with their compofition, When 
this method, the only certain and decifive one, was once 
chofen, it was no great difficulty to difcover that the whole 
art did not depend on any procefs like that employed in re- 
gard to iron, but on the addition of a certain quantity of 

9 fome 


Me Fg eC 


On the Art of Hardening Copper. a3 


. fome other metal melted with the copper, by which it was 

rendered harder than before. 2 

The abbé Mongez firft wrote a treatife on the metallic 
compofition of the ancient bells, which he tranfmitted to the 

Academy of Infcriptions. He found that this compofition 

was in general nearly the fame as that ftill ufed for bell-me- 
‘tal, that is, copper and tin. M. Mongez afterwards tranf- 

mitted to M. Dizé the point of an ancient copper dagger, 
the appearance of which on the fracture fufficiently fhewed 
that it had been fufed and caft. When diffolved in pure ni- 
trous acid, there remained a white powder, found to contain 
tin, and that which had been diffolved was merely copper. 

It evidently appeared, therefore, that the fuppofed art of the 

ancients for hardening copper, was nothing elfe than fufing 
_ it with a certain quantity of tin. This was ftill farther cons 
firmed when M. Dizé found the fame component parts in 
fome Greek, Roman, and Gallic coins, which he obtained 
on the fame occafion for the purpofe of examination. The 
tin in them formed about twenty-four parts in a hundred of 
the mixture. 

- In fupport of this opinion, refpecting the art of hardening 
copper among the ancients, I have the honour of laying be- 
fore the Academy fome experiments lately made on this fub- 
ject.—Latt faummer, Profeffor A. I. Retzius, of Lund, tranf- 
mitted to me a part of the blade of a two-edged dagger, 
which, together with-fome ftone-cutters’ chiffels, were found. 
in a hill of earth on the low lands of Scandinavia, where 
whole fwords of ancient workmanfhip have often been found. 
This fragment, on the outfide, had rather a yellowifh appear- 
ance like brafs, than the red colour of copper; the edge was 
exceedingly thick, and_roundifh; the fraéture feemed alfo 
granulated, which evidently fhewed that the work had been 
caft, When tried by the file, it was not quite fo hard as the 
common bell-metal, but fomewhat harder than common 
gun-metal. The newly-filed furface had a reddith-yellow 
appearance, but foon became yellower. When melted by 
the blow-pipe, this compound metal exhibited no traces of 
zinc; butit might be readily feen, by its appearance, that the 
greater part of the mixture was copper, The filings were 

Vou, V. Na not 


974 . | . On the Art of Hardening Copper. 

not in the leaft attracted by the magnet, which clearly proved 
that there was *ho iron in the compofition. It exhibited as 
little traces of any other metals, as far as could be judged 
from the afcending vapour, In order to afcertain with what 
nictal the copper had been mixed, twenty-five affayer’s 
pounds of the pureft filings of the above fragment were col- 
_leéted 5. pure nitrous acid was heated in a mate retort, and 
; aiited with difiilled water; and a few of the filings were 
thrown into it: when the firft quantity was diffolved, a few 
. more were added, and this was continued till the whole quan- 
_,tity was put in. | The folution was made to boil for a quarter 
of an hour, and then diluted with a little more diftilled wa- 
ter, in order that a white powder, which remained undiffolv- 
ed, and which I fufpeéted tobe calx of tin, might more rea- 
dily fall to the bottom. After this was done, the bright blue- 
coloured folution, which was found to contain nothing but 
copper, was carefully poured out, and diftilled water was 
: poured | over the white, powder, which was wafhed feveral . 
times in the fame manner, after it had each time remained 
at reft long, enough to allow it to fettle, when it was thrown 


_tpon filtering paper to be farther wafhed. This white pow- 
der, when dry, weighed 5: affayer’s pounds, which gave 215 
pounds of tin calx in the whole hundred. Now, tin calx : 
lofes, by being revived, {, or 25 per cent, of its weight; and ~ 
therefore this 21; pounds of tin calx muft have given 16; | 


pounds of metallic tin in the hundred, which, in an experi- } 
ment made for the purpofe, was found to be nearly the cafe, 
and the regulus obtained was found to be pure. The metallic. 
compound of the before-mentioned dagger blade was made ~ 
therefore of 837 copper, and 16% tin; or, to reckon without i 
fractions, of 84 parts of copper, and 16 parts of tin, ‘a 
By way: of experiment, a compound of this kind, confifting ey 
of pure copper and pure tin, was fufed, and a penknife blade : 
was made of it, which was polifhed and ground in the ufual b 
manner. This blade had all the properties and the external ; 
appearance of the fragment of the dagger. Where'the edge 
was thin, it was eafily turned: it was therefore thought that i 
perhaps, in the dagger before mentioned, the proportion of — 
_ tinwas greater. To ideal this point, another compofition — 
was 


On the Art of Hardening Copper. 275 


was made, of 20 parts of tin and 80 of copper, and a knife - 
-blade was made of it, as before. This was much whiter and 

hatder, but alfo brittler in the fame proportion, and there- 

fore broke by careleffnefs in the polifhing. The edge, how- 

ever, was fo fharp that it could be ufed for making pens ; 

but it did not ftand long, as notches were formed in it by 

each cut. 

When the tin makes twenty-five hundred parts in the 
mixture, it becomes rather white than red, but eXceedingly 
brittle. If the addition_of tin be increafed to thirty in the 
hundred, or more, both thefe properties are increafed in the 
fame proportion, and the compofition becomes fit for {fpecula. 
In gun-metal tin makes nine parts, or more, in the hundred : 
in bronze, 84 parts of copper are mixed with about 16 parts 
of tin, but a confiderable portion of zine or brafs is fometiines 
fubftituted for the latter. Bell-metal contains in general 76 
parts of copper, 19 of tin, and 5 of brafs, or thereabouts. 

What has been here faid may perhaps be fufiicient to con- 
firm the opinion refpecting the art employed by the ancients 
to harden copper, and may furnifh fome hints for the em- 
ployment of fuch compounds in common life. Befides, we 
are hereby enabled to appreciate the different opinions enter- 
tained on this fubject.. M. Monnet imagined that the cop- 
per in ancient times was mixed with arfenic, which rendered 
it hard. No real objection can be made to this being pof- 
fible; but as long as no ancient implements made of this 
mixture are found, the above affertion may at any rate be 
doubted, without mentioning other circumftances which 
feem dire&tly to oppofe it. 

M. Dizé * mentions the addition of iron to copper, as the 
means of rendering the latter harder; and endeavours to 
prove that Geoffroy the younger, who firft drew this con- 
clufion, (from an experiment he made, where copper, mixed 
with fixteen parts of iron in the hundred, was found to 
be equally hard, to have the fame grain on the fracture, and 
to be as fit for making cutting inftruments as the hardened 
copper of the ancicnts,) was too precipitate in forming his 


* Yourmal de Phyfique 1790, April. 
Nn2 opinion, 


276° On the Art of Hardening Copper. 


opinion. The queftion, however, affumes a different appear- 
ance, when we take into confideration the experiment as re~ 
Jated by Conant Caylus, in his work on the Egyptian, Etruf- 
can, Greek and Roman antiquities *: for it there appears that 
M. Geoffray undertook the above-mentioned experiment by 
the defire of Count Caylus, who defcribes various kinds of 
arrows and javclins of ancient workmanthip, which, though 


they had the appearance of copper, were mixed with iron ;. 


becaufe filings of them were attracted by the magnet; be- 
caufe the fraéture had a different appearance from that of 
other inftruments made of the hardened copper of the an- 
cients mixed with tin, and was at the fame time lefs fufible, 
M. Geoffroy thinks it rather remarkable that mankind fhould 
fo early have fallen on the method of uniting copper with iron 
in an uniform mixture, which even at prefent is confidered 
as a difficult procefs. It is well known that the moft com- 
mion copper ore confifts of copper and iron mineralifed with 
fulphur, and which is called pyrites of copper; not that the 
copper makes the greater part of it, but becaufe the copper 
is of the greateft value, though the iron feems moft generally 
to conftitute the principal component parts. When this ore 
is fmelted, the firft copper obtained, or the fo called black 
or raw copper, is neceffarily rendered impure by a greater or 
lefs quantity of iron, according as more or lefs care has been 
employed to feparate it during the operation. It is therefore 
in our power, it is faid, not only to obtain copper combined 
in this manner with ag much iron as may be neceflary, but 
alfo to caft all kinds of inftruments of it, and afterwards ta 
hammer them cold, or to expofe them to the fame procefs of 
hardening as if they were of pure fteel. Some affert that this 
method has been attended with complete fuccefs; Count 
Caylus‘tried alfo to harden pure copper-by melting 3 but, in- 
ficad of becoming hard, it was fqund fofter and more malle- 
able, which agrees with what has been faid jn the beginning 
of this paper. , 
Without in the leaft leflening the credibility of this affer- 
tion, which feems to have great probability in its favour, we 


% Recueil d’ Antiquités Egyptieunes, Etrufques, Grecques et Romains, 
Vol, 1. p.238e-251. 
may 


——_- 3 


. = 


— 


9 


ees ee 


> «tee ee he Se 


ee ee 


'——™ 


On the Art of Hardening Copper. 277 


may at leaft exprefs a with that fome perfon would make, 
of copper mixed in this manner with iron, different in- 
flruments, and then endeavour to fhew. real antique works 
made of the fame mixture, in order that they may be com- 
pared. Until this be accomplifhed, it will be beft to adhere 
to that procefs which feems to have been chiefly followed, 
and of which indubitable proofs are ftill in exiftence. 

The hiftory of the antiquity and ufe of metals in the period 
to which this queftion properly alludes, is involved in fo great 
darknefs, that nothing decifive on the prefent fubject can be 
derived from it. This much, however, is certain, that the 
works of ancient authors {till extant fpeak of gold, filver, 
copper, iron, tin, and Jead, as known at the fame time, 
and employed for various purpofes. In regard to copper in. 
particular, it is found more abundantly in a native ftate 
than any other metal, and requires nothing farther than 
{melting to be immediately ufed. In procefs of time man- 
kind would become acquainied with the art of extracting the 
metal from other ores of copper; not, however, without 
greater labour, and therefore at firft none but rich ore could 
be ufed; and we may with juftice conclude, that copper was 
one of the firft metals worked. 

Tin is not found in a native ftate, but its ore is abundant 
in certain places, and is eafily revived, or brought to the me- 
tallic ftate, efpecially when people are acquainted with the 
procefs of {melting other metals. The antiquity of tin, there, 
fore, is as well eftablifhed as that of the other metals among 
which it is named. In the time of the Tyrians a confider- 
able trade was carried on in this metal, which they brought 
from the Caffiterides iflands, beyond the pillars of Hercules, 
under which name England 1 is no doubt meant. 

Whether the art of mixing thefe two metals together by 
fufion was firft found out by accident, or by experiments 
made for the purpole, it is not tq be daubted that caft works 


of fauch a compofition are mentioned at. the fame period with 


the fimple metals. Befides, the works in bronze of the an- 
¢ients are a fufficient proof of their {kill in combining me- 
tals, of their art of modelling after Natyre, and of their 

readiness 


278, On the Art of Hardening Copper, 


readinefs in cafting. All their inftruments and edged tools 
of this kind hitherto found have been caft, and not ham- 
mered; and of this kind, without doubt, were the inftru- 
ments mentioned by Profeffor Pallas as having been found 
near the Tfchudi mines. Al! of them, except a few, con- 
Alted of a compofition of copper and tin. 

The art of preparing and feparating i iron may have been 
difcovered as early as that of preparing other metals. As this 
art, however, requires a greater degree of dexterity, it was 
doubtlefs lefs common at firft, and muft have been diffufed’ 
more flowly, This muft have been the cafe much more 
with the art of preparing ftecl, which naturally would be 
much later than that of preparing iron, and melting tin and 
copper. The method of preparing fteel may have been ge- 
| nerally known in one country before it was communicated 
to another, where copper, hardened in the above manner, 
may have been ufed in its ftead. The Japanefe ftill ufe mir- 
rors of white copper, which confifts of a mixture of that me- 
tal and tin. The metal of the Chinefe gongs confifts of cop- 
per, mixed with 18 parts in a hundred of tin, and probably 
a little nickel ; and thefe inftruments are at the fame time 
fubjeted to ftrong hammering when cold. The Chinefe 
form their ill-fhaped razors of iron (not hammered) filed to 
an edge, and which cut fo badly, that, after every ftroke on 
the beard, they muft be drawn over a file. Many tribes 
who have been difcovered in modern times, and who are 
unacquainted with the ufe of metals, employ hard kinds of 
fiones for making knives, hammers, arrow-heads, axes, &c. 
Induftry always fupplies itfelf with its neceffaries, and em- 
loys for that purpofe fuch materials as can be obtained, 
without taking into account the degree of Jabour which the 
preparation of them may require. ? 


ine} 


rf : XII. Experi- 


{[ 279 ] 


XII. Experiments on the Nature and Properties of the Pietra 
- fongaja, Lapis fungs er*, By P. A. Gappt. 


Stones ; in general are in Italy called Pietra; prune, 
which fometimes i is ufed to denote the harder fort of {tones, 
as well as ftones of a certain genus; for example, Pietra 
bigia, obfidiana, nephritica, &c.; and this is the eafe with 
the fo calied Pietra fongaja. 1.1. Ferber may be confidered 
as the firft perfon who gave a defcription of it in his letters 
from Italy. He has remarked alfo that a kind of it isin 
‘common ufe in the houfes of Naples and Rome; and that 
he faw another kind in the pofleffion of M. Fabbroni, at Flo- 
rence; the firft kind; which was found in the chalk-hills 
near Naples, confifted of white calcareous ftalaftites, and a 
number of fmall roots of vegetables; the latter was a hard- 
ened turf, dug up in the neighbourhood of. fome volcanic 
mountains. : 

A few years ago, M. Charles Sparre, chancellor of the 
academy, having been fo kind as to tranfmit tome a piece 
of pietra_fongaja, which he had brought with him from Italy. 
T analyfed it, and found the refult as follows :—It burns in 
an open fire, and emits the {mell of putrid vegetables. When 
burnt in a ftrong fire, the greater part of it becomes dark- 
grey afhes. A hundred parts of this hardened turf, loft 
about fifteen parts in weight. When fufed in a ftronger 
heat, it is converted into a black opaque flag, which, haw- 
ever, is difficult to be fufed. When a {mall part only of this 
earth is fufed with borax, the glafs acquires a dark-green co- 
lour. If a little water be poured over the calcined earth, 
- the water exhibits traces of diffolved pot-ath, -but the earth 
does not appear to have thereby fenfibly decreafed in-weight. 
One hundred parts of the earth, previoufly calcined in a cru- 
cible, being analyfed, were found to contain about 45 of 46 
of filiceous earth, 23 argil, 7 calcareous earth, 20 calx of 
iron, together with traces of magnefian earth and poteath. 

When the pietra fongaja is kept ina cellar, and moiftened 


* Muthroom-ftone, or mufhroom-beaving ftone. ° ' 
4& From Tranfac. Reyod Acad. Stockbolm for 1797. ; 


: with 


280 On the Volcanic Tfland thrown up 


with water, it produces a great many eatable mufhrooms, 


“which in Italy are ferved up at the tables of the great as:dé- 


licacies. It needs excite no wonder that mufhrooms fhould 


“grow on the pitra fongaja, fince a multitude of fruitful 


mufhroom feeds are intermixed in this foft ftalaétites, as well 


. as with the hardened turf found near volcanoes. 


For the information of thofe who may be defirous of 
making mufhrooms continually grow up from the pietra 
fongaja, and of increafing the quantity, it may be neceffary 


"to remark, that this effeét will be produced, if, according to 


the experiment of M. Gleditfch, the mufhroom-ftonés kept 
in cellars be moiftened with water in which mufhrooms have 


~ been wathed *. 


——— =, 


XIE. On the Volcanic [land thrown up in the Neighbourhood 
ef Iceland. By Captain Von LOWENORN, of the Dani/b 
Navy t. 


In the fpring of the year 1783, a volcanic: ifland, thrown 
up in the neighbourhood of Iceland, excited no little atten- 
tion. According to the account of the fea-captain, who firft 
faw it, exaétly at the time when it firft arofe, fmoke and 
flame feemed to rife from the fea, but no land or ifland was 
to be feen. It needs excite no wonder, therefore, that the 
obferver was thrown into the greateft confternation, as, he 
fays himfelf, when he beheld the fea on fire! He and the 
whole crew therefore concluded that the end of the world 


had arrived, and they all began to prepare themfelves for 


the awful moment: but, as they heard no trumpet, and as 
the fun fhone in the firmament with his ufual brightnefs, 
after confidering what the phenomenon might be, they 
at laft concluded that Iceland had been fwallowed up by an 
earthquake; that this was a remainder of it; and that the 
flames arofe from Hecla, the well-known volcano of that 


—ifland. Full of this idea, they were juft on the point of re- 


* Does no: this furnifh a hint to thofe who rear mufhrooms in gardens 
on beds of hdrfe-dung >? Eptr. 

t From Geographifche Bphemeriden, 1399: , 

; 5 . turning, 


in the Respbbour hood of leeland: 28% 


“tenn ine, m order to conyey intelligence: of this event to 
Denmark; but very Juckily they foon after difcovered the 
ic of ase 

| The place where this volcanic eruption was feen, lies ‘ck 


: 73 nautical miles, fifteen to a degree, from the fouth-wett 
i » extremity of Iceland. . Hitherto they had feen no land, but 
of recognifing Iccland,: the {hip reached the place of deftina- 
¥ tion, and completed her yoyage. , Other fhips, which arrived 
.. later, faw a {mall ifland from iia the eruption had arifen; 


~ but it always, exhibited, as. might naturally be expected, a 
different Appestan ce The fame year fmoke and flames were 
feen to arife from the neareft part of the oppofite- coaft of 
Iceland. 

_ As there have been many inftances of fuch eruptions from 
the fea producing iflands, this event attra¢ted the notice of 

“ government, and the year following orders were given to the 
fhips bound to Iceland to examine the new ifland; but it 
had entirely difappeared, fo that no traces of it were to be 
found. Towards the conclufion of the year, however, an 
unfortunate accident happened, which, without doubt, was 
-occafioned -by, funken rocks forming a part of the ifland 
which had difappeared. 

A Danith fhip of war of 64 guns, calledthe Infcd/retten, 
was expected from the Eaft Indies, and intelligence had al- 

“ready been received that. fhe had failed fron{ the Cape of 
Good Hope; but after that period no farther account; was 

. heard of her till the year 1785, when fome veflels returning 
from Iceland reported, that fome fragments of this fhip,’ to- 
gether with the long-boat, had been driven afhore on the 
coaft of that ifland. According to every account, and by 
comparing the different cireumflances, it appears to me cer- 
tain that the above fhip was wrecked on thefe rocks, then no 

‘longer vifible above the furface’ of the feae It is impoffible 

- *that fuch a large boat could have been conveyed froma thip, 
without the hands of men, unlefs the fhip had been dafhed 
to pieces. _ This, boat, was not only driven to land entire,, 
and in good condition, though without any perfon in it, but 
there was found in it a box filled with wax candles; At the 
diftance of about a quarter of a mile from the boat there were 


- 


4 VOL: V, Oo found 


* 


.w 
t; 
* 


284 On the Volcanic Ifland throx wn up 


founil various pieces of the fame fhip, which could be eafily 
known by fome diftinguithing marks. Thefe parts, of difs 
ferent forms and fizes, would not have been thrown on fhore 
fo near each other if the misfortune had happened at 4 
greater diftance; the billows, currents, &e. would certainly 
have driven them on fhore at places more remote from eacli 
other. Befides, thefe fragments were driven on fhore by 2 
wind which blew i a direction from’ thefe rocks, -and no- 
thing elfe of this misfortune had been perceived on the coatt. 

From all thefe circumftances I conclude that this veffel 
had experienced a very bad voyage home from the Cape of 
Good Hope, for that year cafterly winds were. exceedingly 
prevalent in the northern feas. A great many thips, and 
particularly men of war, preferred goiug round Great Bri- | 
tain to the paflage through the Channel. It is probable that 
the fhip in queftion may have been in want of fome neceflary, 
fuch perhaps as frefh water. The captain, befides, was well 
acquainted in Icefand, where I myfelf was with him, fome 
years ago, as lieutenant om board a fhip which he then com- 
manded, andon this account he probably intended to run into 
fome of its harbours, but unfortunately ftruck on the funker: 
rocks, the remains of the volcanic ifland. In this diftreffed 
fituation the crew,: no doubt, had recourfe to the only pro-+ 
bable means left for faving their lives by hoifting out their 
long-boat, and while employed im this labour the fhip, it is 
likely, went+to pieces, and the people were loft, as none of 
them were ever feen or heard of. 

During my expedition to Iceland im the year 1786, I 
made it my bufinefs to make fome refearches in regard to 
this volcanic ffland, though at that time no fufpicion was 
entertained that the above fhip had been wrecked in this 
place; for this conjecture was only a confequence drawn 

from my refearches. 

"When I arrived in Iceland, where, on account of the bu- 
finefs entrufted to my charge, as well as on account of the 
obfervations which I was obliged to make for the improve- 
ment of charts, I found it neceffary to remain fome time 
with my fhip in Holmens-hafen, amd had at my difpofal a 
fmall veffel which was lying there, F ordered Lieutenant, 

now 


eS 
7 


in the Neighbourhood of Iceland. 233 


- ) 
now Captain Grove, to cruife about with this fmall veffel in 
the neighbourhood of the place where the volcanic ifland had 
been feen. He remained there fome days, and though he 
often founded with a line of more than a hundred fathoms, 
found no bottom, fo that he loft all hope of making any dif- 
covery ; but, juft when he was about to return, he obferved; 
contrary to all expectation, that the waves broke over fome 
rocks lying exactly level with the furface of the water. As 
he now entertained no doubt that he had found what he had 
been fent in queft of, he took the bearings and diftances from 
the neareft part of the coat of Iceland, and tranfinitted to me 
an account of his obfervations, 

When the bufinefs of the expedition was ended, and I 
was about to return at the end of the fummer, I refolved to 
vifit this interefting point myfelf, and to afcertain its real 
pofition by actual obferyation. I took my departure, there- 
fore, from fome {mall iflands, or rocks, which lie before Cape 
Reikianés, the fouth-weit extremity of Iceland, and the out- 
ermoft of which is called the Grenadier’s Cap, diftant 32 
miles fouth-weft from the Cape. As the weather was exceed- 
ingly favourable, I was fo fortunate as to obtain its latitude 
by the meridian altitude of the fun, and its longitude by a 


timekeeper. Though the timekeepers which I carried with 


me were not of the beft kind, as I had quitted the fame day 
one of the ports of Iceland, where [ obferved their rate of 
going, their relative errors could not be of reat importance. 
I determined, therefore, the pofition of the rock called the 
Grenadier’s Cap at 63° 43’ 40” north latitude, and 25° 
35’ 40" weft longitude from the meridian of Paris, This 
agreed pretty nearly with the oblervations of Verdun de la 
Creune, Borda, and Pingré *; efpecially as 1 have good rea- 
fon to believe, that, from a want of fufficient knowledge of 
the coaft of this country, they placed Cape Reikiands three 
minutes too far north, as they make the latitude to be 63° 


55’ As I found alfo, by the moft accurate obfervations that 

could be made at fea, that thefe dangerous rocks lie 47° in a 

' direction fouth-weft from the true meridian, and juft four 
J 


* Forage fait par erdre du Rei en 39734 317% 
mG 00% tuiles 


284 On the Volcanic Ifland thrown up 


smiles from the before-mentioned Grenadier’s Cap, the pofi- 
tions of thefe rocks will be 63° 32'45’’north latitude, and 
20° 2 50” weft longitude from the meridian of Paris. 

As I now proceeded to get a fight of thefe rocks, Captain 
Grove, who was on board my fhip, concluded, from his 
former obfervations, that we could be at no great diftance 
from them, having now quite loft fight of the Icelandic 
coaft; and the before-mentioned rocks, which lie to the 
fouth-weft from Iceland, though the weather was clear, 
being now fcarcely ‘difcernible. My companion, therefore, 
atked whether it was prudent to advance fo ftraight upon it, 
While we were talking on this fubje& the people called out, 
and immediately every eye was direéted to the fpot, where 
we faw before us the waves breaking over a rock. We int- 
mediately put about fhip, and heaved the lead, which was 
in readinefs, and found the depth twenty-fix, and foon after 
forty fathoms, but a little farther no ground was to be found 
with a line of a hundred fathoms. Some tallow had been 
put into the bottom of the lead, as ufual, to enable us to de- 
termine the nature of the bottom by the fubftances which 
adhered to it. By thefe means we obtained fimall fragments 
of ftone which were entirely lava, or of a volcanic nature. 
The rock is not large, and the water around it is exceedingly 
deep. Its height is exactly equal to that of the furface of the 
fea, or rather a little lower; and for that reafon it cannot be 
feen till one approaches very near to it, or when the waves 
break over it. 

The origin of the volcanic ifland, which was feen in this 


place in the year 1783, I explain 1 in the following manner:— 


The rock which now remains formed the crater, which at 
that period threw up flames and {moke; The large quantity 
of lava which iffued from it, being accumulated on the bot- 
tom of the fea around the crater, may at length have been 
raifed above the furface of the fea, and even to a confiderable 
height. But as this volcano lies in a part of the ocean where 
prodigious billows prevail, and roll over each other through- 
out a wide extent of fea, it is probable that fuch a finGure 
would foon be defrayed by their violence, efpecially as there 


is a great depth of water around it, in which it might eafily 
be 


=——=—— sl 
- 


i 


in the Neighbourhood of Iceland. 285 


be overturned. It is.known alfo that the fame year.a con- 
fiderable quantity of pumice-ftone and volcanic fubftances. of 


. the like kind, the fpecific gravity of which was lighter than 


ihat of water, was caft on fhore in Iceland, and found float- 
ing on the fea by mariners. 

Had the eruption taken place in a calmer fea, and the 
depth around it been lefs abrupt, the thrown up mafs. would 
have confolidated itfelf by its own weight, and would have in 
time become an ifland; of which we have had inftances in 
the Archipelago, in the Eaft Indies, and different parts of 
the ocean. Had it taken place on the continent, or in an 
ifland, it would have formed a mountain. It is not necef- 
fary that a voleano fhould always arife from a mountain: 
volcanoes have been feen to burft forth in plains; but the 
invariable confequence is, that the volcanic matter, by being 
accumulated, and, as it were, piled up, forms a mountain. 
Now, as the violence of the waves may have eafily wafhed 
away the loofe matter accumulated round the crater, there is 
no abfurdity in fuppofing, that, as the billows rolled over the 
mouth of the crater, the fire was at length overcome by the 
water, and the volcano extinguithed. 

The crater, confifting of rock, has remained. It is well 
afcertained that a rock exifted in this place before the erup- 
tion; and it is confirmed, by late obfervations, that it exifts 
fill. An obfcure notion prevailed among the feamen who 
frequented Iceland, that there was a blind rock * in this 
neighbourhood called Fugle-Skzir (Bird’s rock). This name 
T have retained in my charts, though the exiftence of it is 
denied by many feamen, becaufe they paffed without feeing it. 
But, under fuch circumftances, the teftimony of one who 
has feen it is of more weight than a hundred who deny its 
exiftence becaufe they did not fee it. This confirms me in 
the opinion that the crater had exifted long before in,the 


fame ftate. 


To conclude, it may not be fuperfluous to remark, in 
order to ftrengthen this opinion, that, nearly in the fame di- 
reCtion from the fouth-weft extremity of Iceland, as already 
Jnentioned, there are five fmall iflands or rocks, the outer- 

* Rocks lying under the water, and'which are therefore more dane 


gerous, are by feamen calle dlind rocks. 
moft 


286 Experiments on fome peculiar Matters 


moft of which lies at the diftance of 3% miles from Cape 
Reikianés. Between thefe the water is deep; ‘hips which 
go to, or come from, the weft fide of Iceland, commonly 
pafs through them, when they firft get fight of the land 
and rocks. By the Danifh feamen they are called Fugle- 
Skisr, becaufe they are frequented by a great number of fea- 
fowl]; but by the inhabitants they are called Eld Eyarne, 
(fire iflands.) May not this afford reafon to conjeéture that 
in former times they had volcanic eruptions? and the vol- 
cano which appeared in the year 1783 may probably have 
exifted long before. 


2 ———— 


XIV. Experiments on some peculiar Matters drawn from 
Animal Subfiances treated with the Nitric Acid> By 
©, WELTER * 


Tue author having treated filk with the nitric acid, to 
obtain from it the oxalic acid, was furprifed to find that at 
the end of his procefs he obtained a filky-Jooking falt of a 
golden-yellow colour, and which, on the approach of a piece 
of red-hot coal, exhibited all the effects of gunpowder. . As 
he made the experiment only once, he thought it of import- 
ance to give a particular account of the procels, i in order that 
it might be repeated. 

On one part of filk he poured fix parts of nitric acid of the 
fhops, adding a little concentrated nitric acid. After it had 
refted two days, he diftilled this mixture. He then poured 
what had paffed into the receiver, on what remained in the 
retort, and filtered the whole. The oxalic acid cryftallifing 
on the filtre, he put the whole again into the retort; and 
added a pretty large quantity of water, which had ferved to, 
wath the filtre. He diftilled off a part of the water; but as 
the refiduum did not cryftallife, returned, by elevating the 
receiver, what had paffed over; and, after repeating this ope- 
ration feveral times, obtained for refiduum an acid liquor of 
the weight of the filk employed, and which contained fmal] 
granulated cryftals, 

This liquor fhewed no traces, of the oxalic acid. It'was 
yellowifh, aud communicated that colour ta:the fingers and 
* Bulletin des Sciences, Vol. II. No. x. 

tg 


aS soe | 


) 4 
/ 


drawn from Animal Subfiauces. 287 


to filk. The tint was not in the leaft. weakened by wafhing. 
GC. Welter faturated this liquor with lime; and having com 
centrated it, he added alcohol, which took up a matter of a 
gummy appearance. The alcohol, diluted with water, being 
evaporated, there remained a yellow fubftance mixed with 
folutions of the nitrat and muriat of lime. Thefe falts were 
decompofed by carbonat of pot-ath, and the liquor, feparated 
from the carbonat of lime, was fubjeéted to evaporation. It 
gave golden-coloured cryftals, which had the finenefs of filk; 
and detonated like sunpowder, producing a black fmoke. 
Thefe cryftals are foluble in water and alcohol, and cryftallife’ 
on cooling. They are deprived of their colour by the oxygen- 
ated muriatic acid. The fulphuric acid difengages from them 
the odour of the nitric acid. The muriatic acid precipitates, 
from a folution of them, {mall micaceous, whitifh, volatile cryf- 
tals, which in the fire exhale a bitter and inflammable fmoke. 

This golden-yellow coloured detonating and cryftallifablefub- 
ftance i3 by the author called amer (bitter) ; its cryftals appear 
to be oétaedral. As.animal fubftances become yellow by the 
contact of the nitric acid, C. Welter endeavoured to extra 
amer from raw beef; but he found it combined with another 
fubftance, which, like it, could not be altered by the nitric 
acid. This combination, foluble in the concentrated nitric 
acid, is feparated from it by water, under the form of a yellow 
powder, which does not lofe its colour by expofure to the air, 
and which might perhaps be ufeful in painting. 

What made, C. Welter prefume that this powder is com- 
pofed of amer and another fubitance, is, that he obtained the 
Jatter by treating fponge with the nitric acid. It is colour- 


lefs, foluble in concentrated nitric acid, and fuffers itfelf to 


be precipitated by water like the preceding powder. 

What has been here faid feems to fhew that animal mat- 
ters treated with the nitric acid give a3 refiduum two fub- 
ftances unalterable by that acid, and which are found either 
in the {tate of combination, or feparate. It appears that filk 
gives pure amer, {ponge gives the fecond fubftance pure, and 
beef a combination of both. The amer is yellow, and foluble 
in water: the combination of both is as infoluble in water 
as the fubftance obtained from fponge, but coloured. 


XV, Reflec- 


my T2889 


xv. Reflections on the ‘eoang of Earthén-Ware, and the 
Refults of the Analyfis of fome Earths and common Kinds 
of Earthen-Ware. By C. VAUQUELIN*. 


Four things may occafion the difference in the quali- 
ties of earthen-ware: 1ft, the nature or compofition of the 
matter: 2d, the mode of preparation; 3d, the dimenfions 
given to the yeffels; 4th, the baking to which they are fub- 
jected. By compofition of the matter, the author under- 
ftands the nature and proportions of the elements of which it 
is formed. Thefe elements, in the greater part of earthen- 
ware, either valuable or common, are filex, argil, lime, and 
fometimes a little oxyd of iron. Hence it is evident that it 
is not fo much by the diverfity of the elements that good 
éarthen-ware differs from bad, as by the proportion in which 
they are united. Silex or quartz makes always two-thirds at 
leaft of earthen-ware ; argil or pure clay from a fifth to a 
third; lime from 5 to 20 parts in the hundred; and iron from 
© to 12 or 15 parts in the hundred. Silex gives hardnefs, 
infufibility, and unalterability ; argil makes the pafte pliable, 
and renders it fit to be fobs moulded, and turned at 
pleafure. It poffeffes at the fame time the property of being 
partially fufed by the heat which unites its parts with thofe 
of the filex; but it muft not be too abundant, ‘as it would 
render the earthen-ware too fufible and too brittle to be ufed 
over the fire. 

Hitherto it has not been proved by experience that lime 


is neceflary in the compofition of pottery: and if traces of * 


it are conftantly found in that fubftance, it is becaufe it is 
always mixed with the other earths, from which the wafhings 
and other manipulations have not been able to’ feparate it. 
When this earth, however, does not exceed five or fix parts 
in a hundred, it appears that it is not hurtful to the quality 
of the pottery; but if more abundant, it renders it too fu- 
fible. 

The oxyd of iron, befides the inconvenience of communi- 
cating a red cr brown colour, according to the degree of 


* Bulletin des Sciences, Vol. Ul. No, 2. . 
4 baking, 


ay eae 


4 
:] 
4 
¢ 


Reflections on the Quality of Earthen-Ware. 289 


aking, to the veffels in which it forms apart, has the pro- 
perty of rendering theni fufible, and even in a greater degree 
than lime. 

As fome kinds of pottery are deftined to m:It very pene- 
trating fubftances, fuch as falis,- metallic oxyds, glats, &c. 
they require a fine kind of pafte, which is obtained only by 
reducing’ the earths employed to very minute particles. 
Others deftined for melting metals, and fubftances not very 
penetrating, and which mutt be able to fupport, without 
breaking, a fudden tranfition from great heat to great cold, 
require for their fabrication a mixture of calcined argil with 
raw argil. By thefe-means you obtain pottery, the coarfe 
patte of which refembles dreche, or fmall-grained pudding- 
fione, and which can endure fudden changes of tempera- 
ture. 

The baking of pottery is alfo an object of great importance. 
The heat mutt be capable of expelling humidity, and agelu- 
ténating the parts which enter into the compofition of the 


‘pafle, but not firong enough to produce fufion ; which, if too 


far advanced, gives to pottery a homogeneoulnefs that renders 


it brittle. "The fame effect takes place in regard to the fine 


pottery, becaufe the very minute divifion given to the earths 
reduces them nearly to the fame fiate as if this matter had 
been fufed. This is the reafon why porcelain ftrongly baked 
is more or Jefs brittle, and cannot eafily endure alternations 
of temperature. Hence coarfe porcelain, in the compofition 
of which a certain quantity of calcined argil is employed, 
porcelain retorts, crucibles, tubes, and common pottery, the 


pafie of which-is coarfe, are much lefs brittle than difhes and 


faucers formed of the fame fubitance, ground with more la- 


~ bour. 


The general and refpective dimenfions of the different parts 


_ of veffels of earthen-ware have alfo confiderable influence 


on their capability to ftand the fire. 

In fome cafes the glazing or covering, efpecially when too 
thick, and of a nature different from the body of the pottery, 
alfo renders them liable to break. Thus, in making fome 
kinds of pottery, it is always effential, 1ft, to follow the beft 
proportion in the principles ; ad, to give to the particles of 

VoL. V: , P p the 


290 Refleétions on the Quality of Earthen-Ware, | 


the patfte, by grinding, a minutenefs fuited to the purpofe 
for which it is intended, and to all the parts the fame dimen- 
fions as far as poflible; 3d, to carry the baking to the 
higheft degree that the matter can bear without being fufed ; 
4th, to apply the glazing in thin layers, the fufibility of 
which ought to approach as near as poffible to that of the 
matter, in order that it may be more intimately united, 

C. Vauquelin, being perfuaded that the quality of good 
pottery depends chiefly on ufing proper proportions of the 
earthy matters, thought it might be of importance, to thofe 
engaged i in this hianel of manufa&ture, to make known the 
analyfis of different natural clays employed for this purpofe, 
and of pottery produced by fome of them, in order that, 
when a new earth is difcovered, it may be known by a fimple 
analyfis whether it will be proper for the fame object, and to. 
what kind of pottery already known it bears the greateft re- 
femblance. ; 

Heffian Argil of — Porcelain Wedgewood’s 


Crucibles. Dreux. Capfules, Pyrometers. 
Silex -- + = 69: . =<. 43:5 - \ 6% >, 6472 
111 OP Sa SR a: IN 
Fime, = ).« »--. 2 so Be me =. 6 
Oxyd of iron - 8 eee Kon ee oP) 
AY ERR os ieee te i olen ow cam 


Raw kaolin roo parts.—Silex 74, argil 16°5, lime 2, wa- 
ter 7. A hundred parts of this carth gave eight of alum, 
after being treated with the fulphuric acid. 

Wafhed kaolin 100 parts.—Silex 55, argil 27, lime 2, 
iron o'5, water 14. This kaolin, treated with the fulphuric 
acid, gave about 45 or 50 per cent. of alum. 

Petuntzé.—Silex 74, argil 14° 53 lime 5°95 lofs 6. A 
hundred parts of this fubQance, treated with the fulphuric 
acid, gave feven or eight parts of alum. But this quantity 
does not equal the lofs fuftained. 

Porcelain of retorts.— Silex 64, argil 28°8, lime 4°55, 
iron 0150, lofs 2°77. Treated with the {ulphuric acid, this 
porcelain gave no alum, 


XVI. Eleventh 


{ 291 J 


XVI. Eleventh Communication from Dr. Taornton, Pbhy- 
Jfician to the Mary-le-bone General Difpenfary, &c. ec, &e. 
relative to Pneumatic Medicine. 


A REMARKABLE CURE OF AN ULCER OF THE LEG. 


Mr. RODERICK M‘KENNON, aged 67, went in the 
Year £758 as Affiftant Apothecary to St. George’s Hofpite!, . 
Where he had hiswafhing, board and lodging. found him, 
with a fuitable falary. In June 1795, whilft in this employ, 
he went to fee Dr. M‘Nab, who then refided in Great Suffolk- 
ftreet ; and as he was at the door, a bitch in the houfe, who 
had puppies, furioufly flew at him, and feized him near the 
calf of the leg, making a d-ep lacerated wound. The wound 
foon after became dreadfully inflamed, poultices were applied, 
and it was near a fortnight before he made his cafe known 
to the furgeons of the hofpital. He was now confined to his 
toom, and thefe moft experienced and eminent practitioners 
continued their humane attentions to him above a twelye- 
’ month, trying a variety of different applications, until, find- 
ing his cafe baffle all their endeavours, he was difmiffed his 
employ, and left the hofpital as incurable. Added to this 
dreadful and unforefeen affi@tion, he-had an afthma, which 
had exifted on him above ten years, and was obliged fre- 
quenily to fit up the greateft part of the night with the win- 
dows wide open to procure bréath. He was now in the vale 
of years, and with a gloomy profpeét before him ; for no 
falary was allowed this almoft fuperannuated fervant of a 
public charity, to which he had) been attached above thirty 
years 5 and he had a wife and daughier to provide for. After 
quitting the hofpital, Mr. Carpue, a furgeon no lefs diftin- 
(guifhed for zeal than abilities, for fome months attended him ; 
but finding all his endeavours ineffectual, he reluctantly fe 
his leave of him as incurable. Such was the deplorable ftate 
_ of this unfortunate fufferer, when Mr, Carpue recommended 
him for the trial of the oxygen air, ufing thefe very expref- 
“fions: ‘ Poor Roderick has been under Mr. Home’s care,” 
(0 eminent furgeon, brother-in-law to John Hunter,) “ in 
Pp 2 St. 


‘ 


292 Eleventh Communication from Dr. Thornton. 


St. George’s Hofpital, which he left as incurable, and fince , 


under my care foy feveral months ; and fo bad is.his-cafe, 
that I am fare if you can cure him you can cure the devil.” 
Being no furgeon, I could have no with, to accept of fuch 
acafe but for the caufe of humanity and the fake of feience ¢ 
and I feel extreme delight in faying, that poor Roderick is 
now perfectly cured, the ulcer is healed, his afthma. gone, 
and, in order that the philofophic world may fee fuller par- 
ticulars refpecting this extraordinary cure, I am happy to 
be able to add the following teftimonies : 


A Letter to Dr. Thornton, from Mr. Carpue, Surgeon at the 
York-Hofpital. 
DEAR SIR, 


T have feen Mr. M‘Kennon, and have examined his le¢, 


and think the cure you have wrought on it is indeed very , 


aftonifhing. When he firft came. under my care, he laboured 
under an immente ulceration, extending from the externa! 
ancle of the right le, which reached as high as the jun&tion 
of the *erid6ts of the gattrocnemii and folzeus mufeles. At 
this period the tendons of the peroneal mufcles had fluffed, 
and in confequence I applied charcoal, which produced very 
confiderable good ; but upon mentioning this to a friend, 
who knew the cafe well*, he faid, ‘It was immaterial 
what remedy T ufed, for it was a café in which he was 
certain nothing would prove effectual.””. After this I applied 
the diluted nitrous acid, and feemingly with advantage; bat 
being obliged to go mio the country, I left him under the 
care of another furgeon; and when I faw him, after an 
abfence of fix weeks, 1 found the fore ina very unfavour- 
able condition; and for fourmonths I ufed different applica- 
tions, but to no purpofe, and I conceived the cafe now to 
be perfectly incurable, and as fuch mentioned it to you 
when I had the pleafure of meeting you at Mr. Heavifide’s : 
and I then propofed him to you for the trial of the oxvgen 
air, as his cafe, if fuceefsful, would prove moft decidedly 
its efficacy; for, in the multitude of fore legs I have at- 


** We belicve this to be Dr. Baitcy, phyfician to St. George's Hofpital. 
tended, 


Bleventh Communication from Dr. Thornton. 293 


tended, I mutt acknowledge I never faw a worfe cafe, old 
Welt-India fores excepted. 
I have'the honour to be, Sir, 
Your obedient fervant, 


j | J. C. CARPUE. 


} 


Having referred Mr. M‘Kennon to Mr. Spencer, a furgeon 
in Charlotte-ftreet, Fitzroy-fquare, who adminifters the pneu-~ 
piatic remedies, I received the following letter : 


A Letter to Dr. Thornton from Mr. Spencer. 
SIR, 


I here enclofe the treatment and the progreffive cure of 
the ulcer which occupied the external ancle of the right 
leg of Mr. M‘Kennon, For fix weeks, by your direction, 
he daily took a gallon of oxygen air, mixed with four times 
that quantity of atmofpheric air. The ulcer difcharged pro- 

_perly, but feemed to heal very flowly : in confequence-I gave 
him a double dofe, and after a fortnight it produced very 
feverith fymptoms, when he took by your order fome pur- 
gatives, and then he refumed his ufual dofe of fuperoxyge- 
gated air daily, until the ulcer, diminifhing by degrees, was 
at laft completely healed, there being no difcharge, the whole 
cicatrifing, and the new-formed furface looking: extremely 
healthy. During this period no particular application or 
drefings were made ufe of by me, nor any medicine directed 
“by you, but what before he faid he had taken gallons of ; fo 
that I attribute his extraordinary cure entirely to the efhcacy 
of the oxygen air. Happy in being able to give my tefiimony 
to fo remarkable a cafe, I have the honour to be, dear Sir, 
With the profoundett refpect, 
Your obedient humble fervant, 


T. SPENCER. 


REMARKS BY DR. THORNTON. 


_ As Mr. M‘Kennon took bark, fome of the Fagulty may 

not be willing to give to the oxygen air the ment in this 
_ eure; I will therefore endeavour to fiate fhortly my reafons 
_. for attributing every thing to this new remedy. / 
aS i. The 


EN 


294 Eleventh Communication from Dr. Thornton. 

1. The operation of bark had been before tried; he had 
taken, he faid, gallons of it. 

2. When I firft faw him, the fore, and mufeles furround- 
ing it, were wholly infenfible; he did not feel a needle 


Piercing them, nor could he perceive even the corrofive ope=" 


ration of cauftic. 

3. After inhaling the vital air but a few days, fenfibility 
was reftored, as both Mr. M‘Kennon and Mr. Carpue wit= 
neffed. 

4. Haying cleanfed the wound, it would remain dry 5 but 
even whilft inhaling the vital air, the whole furface was im= 


mediately covered with a fine dew, as Dr. Monro and others. 


witnefled. 

5. To fhew the progrefs of amendment whilft inhaling 
the fuperoxygenated air, I am happy to be able to Jay before 
the philofophic world the following teftimony of an impartial 
obferver, Dr. Douglas of Baliol-College, Oxford : 

“© Towards the middle of March 1798, I firft faw Mr. 
M‘Kennon. He had then a large and very foul ulcer, ex- 
‘tending fome inches above the right ancle. From that time 
to the prefent (April 30) I have repeatedly feen him, and 
each time could not poffibly fail to be fenfible of a mof? manifeft 
improvement. At prefent the ulcer is diminifhed at leaft ones 
balf in fixe fince I firft Jaw him; the edges have a fine healthy 
appearance, and its general furface is aftoniflingly altered 
for the better,” 

6. When the oxygen air was left off, the fore remained 


ftationary, and vifibly improved when he again refumed it. - 


7. My ftrongeft arcument, however, is the fuccefs in this 
and in other cafes equally defperate. . 

Mr, Munt had been before cured of a fore leg of eighteen 
years ftanding. 

Mr. ‘Kéieadd was cured of a fore leg of two years. When 
I afked Mr. Cruikfhank whether it was true he had con- 
demned the leg? he anfwered, with his ufual emphafis, “ I 
not only condemned his leg, but his life; for he was of fo 
wafhy a conftitution that he could not have loft the one 
without the other.” 

Next the cure of Patterfon. When T fent him to: fhew 

9 hig 


Eleventh Communication from Dr. Thornton. 295. 


his leg to Mr. Cruikfhank, which ftill poffeffes the marks of 
numerous ulcers, feeing varic fe veins, this experienced fur- 
geon faid: ‘* Tell Dr. Thoruton that he is miftaken if he 
fuppofes he has made a permanent cure; for varicofe ulcers 


were never cured without an operation, which, ifthe wifhes, ’ 


[ will perform.” The man, frightened at firft, and then afto- 
nifhed, replied: ‘ Sir, I have been cured perfeétly now thefe 
three years.’—-“ That alters the cafe,’’ anfwers this diftin- 
guifhed anatomilt; then tell Dr. Thorn‘o.1 that he has per- 
formed a mofi wonderful cure.”’—Patterfon ft']l continues well ; 
nor does there feem the fmalleft caufe to fufpeét a relapfe. 

The cure of Mr. Wilkinfon*, who had a fore leg 
twelve years, is not lefs extraordinary. In this cafe I ob- 
ferved a peculiar phenomenon, alone explicable by the ope- 
ration of the oxygen air. The fingers of both hands at their 


ends looked very red, as red as raw meat, were {wollen, and’ 


felt very painful. The fame was mentioned to me in private 
converfation by Dr. Beddoes in a patient of his, who, finding 
an afthma relieved by a fmafl dofe of vital air, took as much 
as he could at one time, produced a fever, and this fame phe- 
nomenon I haye juft mentioned above. 

This legds me to repeat an obfervation [ have before often 
_expreffed, that oxygen air promifes to be an ufeful remedy 
in fore legs; for why have we not fore arms? The nearnefs 
of this part to the heart feems to be the only philofophic 
reafon; and therefore a direct powerful ftimulus to the heart, 
as oxygen air, promifes the moft certain good, aided by the 
invigorating effects of bark, fteel, and other tonic medicines ; 
not but that I would advife, where itcan be properly done, as 
in hofpitals, trials to be made with the vital air without me- 
dicine, to prevent all cavil;, although it is undoubtedly un- 
_ jmportant to the fufferer by what means he is treated, fo that 
he is but cured; and, until the contrary is proved, I fhall 
_ ever think, that medicines, judicioutly employed, certainly 
" gannot impede the operation of oxygen, but may aff. 

_. I now take my leave of the philofophic world, not from 
' dearth of materials, for I have cures by me yet more im- 

* The cafes of Mr. Munt, the Rev, Mr. Atwood, Patterfon, and Mr. 
penton, are related in Dr. Beddoes’s Copfiderations on Faétitious Airs, 

portant 


¥ {" Were ie oe 
i 


2096 Intelligence, and Mifcellaneous Articles. - 


portant than thofe before related by me, that deferve, I think, 
to be recorded; and daily experience, in a large public chari- 
ty*, where the airs are adminiftered under my direction, would 
afford me other frequent opportunities ; but according to my 
promife, mentioned in my firft communication, I was to con- 
tinue writing on this fabjeCvonly until the eftablithment of 
the Pneumatic Inftitution under Dr. Beddoes, which I am 
happy to announce, and that fhortly the public may expect 
a periodical quarterly publication, relating chiefly to this im- 
portant inyeftigation, from the mafterly pen of that eminent 


phyfician. 


INTELLIGENCE, 
AND 


‘MISCELLANEOUS ARTICLES. 


LEARNED SOCIETIES, 
GERMANY. 


Tue Ele&toral Academy of Sciences at Manheim has 
propofed the following queftion as the fubject of a prize for 
the year 1801 :— 

«© Are the azotic (flick) gafes, which are produced from fo 
many totally difimilar fubliances, and in.ways {fo different, 
exactly the fame in all their chemical properties and bafes 
(imple azotic gafes,) with that of the atmofphere? and has 
the nitrous acid the fame azote for its acidilying bafe, as the 
atmofpherie azotic gas? 

«¢ The partizans of the antiphlogiftic doétrine feem to 
admit both, but without fatisfactory proof. 1, Since, for 


want of fuficiently accurate examination, they admit ig — 


each of thefe wafes all the known properties of azotic gas, 

becaufe they deftroy animal life, extinguith flarse, and ma-~ 

-pifeft no acid properties: but, 2, after all their analytic and 
* The Mary-le-bone General Difpenfary. 

: fynthetie, 


/ 


gag ee ee ee 


-. e 


aS: 


é 


Learned Societies. - 497 
fynthetic proofs, they haye ftill left well-founded doubts, 
(z) whether the electric fpark, in its paflage through oxy- 
gen. or azotic gas, does not itfelf undergo a chemical de- 
compofition, and furnifh the bafis of the -nitrous acid ; 
(2) and how, by the fame means, (a red heat, and the elec- 
tric {park,) the nitrous acid is decompofed into oxygen and 
azotic gafes, and can be again recompofed from them; and, 
(c), fince oxygen and azotic gafes have fo great an affinity 
for each other in the atmofphere, why, when the former is 
added in a fufficient quantity, imperfect nitrous acid is not 
immediately produced, as is the cafe when oxygen gas is 
added to the azote in nitrous gas, by which perfect nitrous 
acid is immediately produced ? 

** The papers on this fubje&t, written either in Latin or 
French, mutt be tranfmitted before the 1ft of November 1800, 
to M. I. Kencdy, fecretary to the academy, with the name of 
the author, in a fealed note, and any motto chofen at plea- 
fure. . The prize is a gold medal, of the value of 50 ducats.”” 


HOLLAND. 


_ The Dutch Society of the Sciences at Haerlem propofed 
in 1793, and afterwards in 1796, the following queftion: 
* What light has Lavoifier’s fyftem, and his method of exa- 
mining organic fubftances, furnifhed towards a more accu- 
rate knowledge of the human body?” But, as no fatisfac- 


' tory anfwer was received, they have propofed it again in the 


following manner :— 

I. As a great number of new difcoveries have been made 
fince the quefiion was firft propofed, and as the cireumftances 
of it have thereby acquired more extent than to admit of 
their being properly comprehended in a fingle treatife, the 
Society have refolved to divide the different objects of it into 
three new queftions for the prefent year, and to fix the period 
of receiving anfwers at the 1{t of November 1800. 

1. What light has the new chemiftry thrown on the phy- 
fiology of the human ‘body ? 

2. How far has the light, thrown on the phyfiology of the 


‘Human body, contributed to a better knowledge than before 


of the nature and caufes of certain difeafes ; and what ufeful 
Vou. V. Qq confe- 


a | | 


298 Learned Societies. 


confequences, more or lefs confirmed by experience, can be 
deduced from it in regard to the practice of medicine? 

3. How far has the new chemiftry contributed to afford an 
accurate idea of the mode of aétion of different internal and 
external medicines, which have beer long ufed, or only lately 
recommended? And, what advantages can arife from a more 
accurate knowledge of this point in regard to the treatment 
of certain difeafes ? 

As fome learned men have mtroduced hypothefes built om 
too weak a foundation, ‘in regard to the application of the 
pr inciples of the new chemiftry to phyfiology, pathology, 
and therapeutics; and as this is highly prejudicial to the 
progrefs of thefe feiences, to which the new chemiftry, how- 
"ever, promifes fo much light, if, according to Lavoifier’s rule, 
we ‘tnt nothing in chemiftry, or the eniployident of che- 
nical principles, but what is founded on decifive experiments, 
the Society requires, that thofe who are inclined to anfwer 
thefe queftions will make an accurate diftin@tion between 
what is proved, and what is merely hypothetical ; and that, 
in regard to hypothefes, the candidates will confine them- 
felyes to a bare mention of them, and of the few grounds on 
which they reft; becaufe the principat point which the So- 


ciety withes to obtain is, that thofe who follow the medical 
or chirurgical profeffion im Holland, and who are not yet 


fufficiently acquainted with the progrefs of the new chemif- 
try, and its application, on well-founded principles, to phy- 
fiolocy, pathology and therapeutics, will procure fach works 
as may be beft calculated to inform them what hight the new 
chemifiry has actually thrown on thefe fciences ; ; and what 
fa&ts are founded on too weak grounds; and what have been- 
too rafhly adopted, or are ftill too doubtful to be depended’ 
on. Each of thefe papers will be examined feparately: thofe, 
therefore, who with to anfwer more than one quettion, mnt 
fend a paper for each. 


II. The Society requires a plan, capable of being carried 


into execution, for rendering productive the large unculti- 
vated difiriéts of the republic, particularly in Guelderland,, 


Overyffel, Drenathe, and Dutch Brabant. 


III, The 


~ 


4 


. 


F 


ES. Se 


Pe a a Ee 


ane 
~ 


Jae 


Foffil Wood found at a great ricignt. 299 


III. The following prize queftions are again propofed :— 
r. A natural hiftory of the whale; in order to furnifh 
hints for its being more eafily difcovered and caught, and 
afterwards converted to ufe. This queftion to be anfwered 
before the 1ft of November 1802. 

_ 2. What has experience taught in regard to the ufe of cer- 
iain animals which in the Netherlands appear to be hurtful ; 
and what means are to be employed for extirpating them ? 
For this queftion no period is defined. 

3- What indigenous plants, the virtues of which have 
been hitherto unknown, might be employed im the. apothe- 
caries fhops in Holland to fupply the place of foreign medi- 
eines? The virtues of them mutt be eftablithed, not by fe- 
reign teflimony, but by the teftimony of natives of the coun- 
try. peri time for anfwering this que {tion is indefinite. 

4. What indigenous plants, not yet employ ed, might be 
introduced into ai as good and cheap food? And, what fo- 
reign nutritive plants might be cultivated for the fame pur- 
pole ?—No definite time. 


FOSSIL WOOD FOUND AT A GREAT HEIGHT. 


In a paper lately read before the French National Inflitute, 
it appears that C. Villars, Profeflor of Natural Hiftory, of 
Grenoble, faw, near a glacier in the department of Here, fome 
foffil wood buried among turf at the height of 2320 metres 
above the level of the fea, and 850 metres above the moft 
elevated Jine at which wood grows at prefent. The moun- 
tain on which this interefling Se ery was made, is that of 
Lans, in the canton of eae The trees found there are, 
mountain-afh, birch, and the common larch. ‘The roots and 
part of the trunks can be plainly diftinguifbed. The Jaft of 
thefe trees docs not grow at prefent in the neighbourhood.— 
The author of this memoir afcribes the greater degree of cold, 
which now prevails on thefe mountains, io two principal 


-caules: firft, the valleys becoming deeper, which has changed 


the elevation of the fummits in regard to their bafes and the 
furroundivs countries: the fecond is the deftruction of the 
ancient are fis, which had gradually extended themfclves to 


great heights, but which, when once deftroyed, cannot grow 


Qq 2 up 


Ss) oe 


300 New Theory of Refpiration. 


up again at the fame heights, becaufe the trees are Lene 
of that mutual fhelter which they afforded to each other. 


NEW THEORY OF RESPIRATION. 


Profeffor Herholdt read lately, before the Academy of Sci- 
ences at Copenhagen, a memoir refpecting fome experiments 
made by him and M. Rafn on living animals, in order to 
difeover the mechanifm of refpiration; having in view, at the 
fame time, the cure of wounds in the breaft. The profeffor 
fhewed that the beft authors en furgery have-hitherto explained 
the mechanifn of refpiration in a manner diametrically op- 
pofite to what it really is; fo that, by applying their theory 
to the cure of wonnds in the breaft, they have followed a 
method altogether falfe. According to his experiments the 
lungs have not, as has been maintained, an expanfive force 
peculiar to them, but the movement is performed by the 
action of the diaphragm, to which fufficient attention has 
not hitherto been paid. When there are wounds in the 
breaft, the atmofpheric air enters by them on infpiring into 
the cavities of the thorax, and iffues on expiring. This has 
been proved by experiments made on horfes, dogs and cats. 

M. Herholdt and Rafn, in examining the manner in which 
the frog breathes, remarked, that this animal is without a 
diaphragm, and that its' lungs at the fame time have no ex- 
pantive force ; but that a {mall membrane, by means of which 
it can fhut its mouth hermetically, difcharges the funGtion of 
the diaphragm ; fo that, when it is prevented from fhutting 
its mouth by inferting into it a fmall rod, the animal dies in 
a few minutes, becaufe it is no longer able to breathe. When 
it is fuffered to fhut its mouth before it is entirely dead, or 
when it 1s only in a ftate of afphyxia, it foon recovers. Ifa 
frog be deprived of this membrane, by cutting it entirely off, 
or only in part, fo that its mouth can no longer be herme- 
trically fhut, it expires in a longer oy fhorter time according 
to the fize of the aperture made: on the firft view it appears 
very paradoxical that man, as well as the greater part of ani- 
mals, lofes his life by not being able to breathe when his 
mouth and nofe are fhut, and that the frog dies becaufe it 
cannat breathe when its mouth is opened. The explanation 


of - 


ee ee ee ey ee ee el, 
. ? 


gee Le 


Medical Pneumatic Inftitution. 305 


of this phenomenon, however, is eafy when we recolleét that 
the lungs have no expanfive force. In confequence of this 
new theory, M. Herholdt has fucceeded in curing very dan- 
gerous wounds made in the breatts of dogs. 

The above experiments, which were communicated to the 
Philomatic Society at Paris, by M. Manthey, were repeated 
with fuccefs, by the commiffioners of that Society, on frogs 
and falamanders, Ifa gag be put into the mouth of one of thefe 
animals, fo as to prevent it from fhutting its mouth, it dies at 
the end of half an hour. The refpiration is performed as fol- 
lows :—The mouth being abfolutely fhut, the frog dilates its 
throat, and the air rufhes in by the noftrils; it afterwards 
contraéts its throat, and the air penetrates to the lungs, be- 
caufe, no doubt, there is a fmall valve in the noftrils which 
prevents it from efcaping by the fame way that it entered ; 
for the membrane, which the Danifh authors affert they ob- 
ferved in the mouth, could not be feen by the commiffioners. 
Lizards and {erpents, which have ribs, breathe like other ani- 
gnals; and a forced opening of the mouth does not kill them, 


MEDICAL PNEUMATIC INSTITUTION. - 


All who wifh well to the interefts of humanity will rejoice 
to learn that this inftitution, as ufeful as novel, is at laft fo 
far eftablifhed that there is every reafonable ground to believe 
the objects of it will now receive that ample and fair invefti- 
gation their importance demands. The learned, ingenious, 
and meritorioufly perfevering founder of it, has already pub- 
lithed a Notice of Obfervations made at the Inftitution, which 
contains fome highly interefting remarks on the effects of a 
gas not before applied to medicine, but which promifes, in 
fkilful hands, to be one of the fafeft and moft powerful agents 
hitherto difcovered. 

Mr. Davy, fuperintendant of the inftitution, than whom it 
would hardly be Repel to find one better auativied for the 


Aituation, having made fome experiments on dephlogiflicated 


nitrous gas, fo named by its difcoyerer Dr. Pricftley, which 
proved that its compofition, properties, and mode of aétion, 
had been mifiaken by the lateft experimenters, was induced 

7 to 


902 Medical Pneumatic Inflitution. 


to inhale it. Dr. Beddoes relates the circumflances in the 


following words : 


“‘ The firft infpirations of the gas produced giddinefs, ful- 


nefs of the head, and, in fhort, feelings refembling thofe of 
incipient intoxication, but unaccompanied by pleafurable 
fenfation. At this next experiment I was prefent. The 
quantity was larger, and the gas more pure. The fcene ex- 
hibited was the moft extraordinary I had ever witneffed, ex- 
cept in the cafe of that epileptic patient, whom I have de- 
feribed (Confiderations on Airs, pat iv. p. 13.) as agitated, in 
confequence of the refpiration of oxygen gas, with along fuc- 
ceffion of the moft violent movements. The two fpectacles 
differed, indeed, effentially in one refpect. In the former 
every thing was alarming: in the latter, after the firft mo- 
ments of furprize, it was impoffible not to recognize the ex- 
_ preffions of the moft ecftatic pleafure. I find it entirely out 
of my power to paint the appearances, fuch as they exhibited 
themfelves to me. I faw and heard fhouting, leaping, run- 
ning, and other geftures, which may be fuppofed to be exhi- 
bited by a perfon who gives full loofe to feelings excited by a 
piece of joyful and unlooked-for news. As in the cafe of 
the epileptic patient, 720 wearine/s or depreffion followed ; fo, 
in this cafe, no exhauflion or languor or uneafy feeling took 


place.’ The experiment Mr. Davy has very frequently re-. 


peated, and generally with the higheft pleafurable fenfations ; 
and, except under particular circumftances, with confiderable 
Sealer exertions, which have not in any inftance been fuc- 
eceded by fatigue or fadnefs.” é 

A number of perfons afterwards inhaled the fame gas: the 
following extracts will convey fome idea of the very fingular 
effects produced by it: 

Mr. J.W. Tobin (after the firft imperfeét trials), when the 
air was pure, experienced fometimes fublime emotions, with 
tranquil geftures ; fometimes violent mufcular action, with 
fenfations indeferibably exquifite ; no fubfequent debility— 
no exhauftion.—His trials have been very numerous. Of 
late he has felt only fedate pleafure, In Mr, Davy the effeét 


is not diminithed, 
Mrs, 


\ 
ee ee 


Medical Pneumatic Inftitution. 303 

*© Mrs. Beddoes—Pretty uniform pleafurable fenfations— 
propenfity to mufcular exertion, could walk much better up 
Clifton Hill—has frequently feemed to be afcending like a 
balloon, a feeling which Mr. Burnet {trongly expreffed. 

* Mr. James Thomfon. Involuntary laughter—thrilling in 
his toes and fingers—exquifite fenfations of pleafure—a pain 
m the back and knees, occafioned by fatigue the day before, 
recurreda few minutes afterwards. <A fimilar obfervation we 
think we have made on others; and we impute it to the un- 
doubted power of the gas to increafe the tenfibility, or nervous 
power, beyond any other agent, and probably in a peculiar 
manner. 

« Mr. Stephen Hammick, Surgeon of the Royal Hofpital, 
Plymouth. In afmall dofe, yawning and languor.—It fhould 


be obferved, that the firft fenfation has often been difagree- 


able, as giddinefs; and a few perfons, previoufly apprehen- 
five, have left off inhaling as foon as they felt this.—Two 
larger dofes produced a glow, unreftrainable tendency to 
mufeular ation, high fpirits, and more vivid ideas. 

«¢ Mr. Robert Southey, for many hours after the experiment, 
imagined that his tafte and fmell were more acute, and is 
certain that he felt unufually ftrong and cheerful. Ina fe- 
cond experiment, he felt pleafure ftill fuperior—and has fince 


poetically remarked, that he fuppofes the atmofphere of the 


higheft of all poffible heavens to be compofed of this gas. 
“Robert Kingleake, M.D. Additional freedom and power 
of refpiration, fucceeded by an almoft delirious but highly 
pleafurable fenfation in the head, which became univerfal, 
with increafed tone of the mufcles. At laft an intoxicating 
placidity abforbed for five minutes all voluntary power, and 
left a cheerfulnefs and alacrity for feveral hours. A fecond 
ftronger dofe produced a perfect trance for about a minute ; 
then a glow pervaded the fyftem. The permanent effects 
were, an invigorated feeling of vital power and improved 
fpirits. By both trials, particularly by the former, old rheu- 

mati¢ feclings feemed to be revived for the moment. 

| &Mr.Wedewood, after breathing fome time, threw the. bag’ 
from him, kept breathing on laborioufly with an open mouth, 
holding 


504 & Medical Pneusatie Inflitution, 
holding his nofe with his.left hand *.without power to take it 
away, though aware of the ludicroufnefs of his fituation—all 
his niufcles,feemed tobe thrown into*vibratory motion—he 
had a violent inclination to make antic ‘geftures—feemed 
Jighter than the atmofphere, and as if about to mount.  Be- 
fore the experiment, he was a good deal fatigued after a very 
long ride, of which he permanently loft iy fenfe.. Ina fe- 
cond.experiment nearly the fame efie&ts, but with lefs plea- 
tak In a third, much greater pleafure.” 

The cafes in which its effe€ts were prejudicial are alfo 
fiated with great candour. Thefe were of the hyfterical kind ; 
but the endearing of the whole of thefe phenomena led to 
a happy application of the gas to the cure of palfy, and of dif- 
eafes proceeding from a defeét of nervous energy; and feve- 
ral inftances of fuccefs are ftated, which are well Asaaving ® 
of attention. 

“We defire further,”’ fays the author, “ to try the effects. of 
our new agent in palfy,and in thevariouscafes of irwe deficiency 
of nervous power, which we have well learned to diflinguifh 
from cafes of relative defect of irritable power. As the limits 
of the efficacy of every remedy ought to be determined, we 


fhall not fhrink from any cafe, by rcafon of its inveteracy. We™ 


intend to oppofe our Nepenthe to the equable decay induced 
by time and intemperance.; and we hope to palliate fome of 
the evils of extreme old age itfelf. 

** We are emboldened by experience to pledge ourfelves for 
the fafe employment of the gas. .We fhall, indeed, be fadly 
difappointed if it do not fometimes prove the moft delicious 
of luxuries, as well as the moft falutary of remedies. In fay~ 
ing this, it may be allowed me to fuggeft to thofe, who have 
not attended to the tenor of my opinions, that I now for the 
firft time venture to hold forth thefe hopes. However ur- 
gently I may have recommended the invettigation, my lan- 
guage, with regard to its iffue, has always been, that I would 
not anfwer for the difcovery of a gafcous remedy in any denomi-~ 
nation whatever of difeafe. That natural or forced decay may 
be repaired, and the faculty of pleafurable fenfation renovated, 


* This was praétifed in all the experiments, 


; 


4 


| 


Chrome found combined with Iron. 305 


is now no longer a mere conjecture fupported By loofe analo- 

gies—we fee the ftrongeft probabilities daily’ accumulating in 

favour of the opinion: It muft only,be remembered, that fo 

defirable a change cannot be effeéted by the agent applied in. 
any manner to any conftitution. It mutt be prope erly uted in 

proper cafes. ‘ . 

* Confidering the prefent abundance of expert chemitts, we 
eannot prelisdie: that others will not be able to prepare tlre * 
gas perfectly without our inftructions. Neverthelefs, thofe 
who attempt to ufe it medicinally fhould be apprized that the 
utmoft care is neceflary in its preparation and employment. 
A deleterious, inftead of a falutary fluid, as the author can 
atteft from his own painful experience, may eafily be obtained. 
Probably neither Dr. Prieftley, nor the Dutch chemifts, ever 
procured that which can be refpired with fafety. The differ- 
ence, and its caufes, will hereafter be pore out. 

“* Tf, therefore, in confequence of that premptitude which 
journals afford, experiments tending to invalidate any part of 


» the preceding fiatement fhould be publifhed, we hope that its 


perfect fidelity willnot on that account be doubted, The ex- 
perimenter will be found to have employed a different agent 
from ours. This we have no hefitation in declaring that we 
fhall be able to thew.’’ 

From the preceding fhort extracts, our readers will fee what 
an interefting field is opened for the advancement of phyfio- 
ogy and medicine; and we hope that fome will be induced 


‘to affift an inftitution, which ought not to be confounded 


with ordinary charitable foundations. It is eftablithed for the 
fake of relieving from a fpecies of diftrefs, from which no de- 
gree of affluence can exempt—namely, that which arifes from 
the imperfect fiate of medicine. Subfcriptions are received 
by Mr. Couts, Banker, Strand, London ; and by Mr, Savery, 
Banker, Briftol. 


CHROMAT QF IRON, 


C. Pontier, correfpondent to the Journal des Mines, 
tranfmitted lately to the Cabinet of the Houfe of Inftruction, 
among other interefting minerals, a fubftance in an irregular 
mafs, of a dark brown colour, having a metallic {plendour 

Vor. V. Rr and 


306 Chrome found combined with Irom, * — . 


and mean hardnefs, the fpecific gravity of which was found 
to be 4°0326. C. Pontier found>it in the department of 
Var, a la Baftide de la Carrade, near Gaffin, and confidered 
it as the brown blende, to which indeed it has a confider- 
able degree of refemblance, except that its fpecific gravity 
is far greater. This fubftance being analyfed in the labo- 
ratory of the mines by G. Taffaert, was found to be chromat 
of iron, that is to fay, a metallic falt formed by the combi- 
nation of iron with the acid arifing from the new metal dif- 
covered by C. Vauquelin, to pibich he gave the name of 
chrome. It feemed to contain, in 100 parts, 63°6 of that acid, 
36 of iron ; lofs, 1-4. Chemifts may now flatter themfelves 
that chrome, which hitherto has been found only in the red 
Jead of Siberia, in the ruby and the emerald, may be ob- 
tained in fufficient abundance to enable them to fubjeét it 
to new refearches. 

C. Vauquelin and Taffaert, by continuing their experi- 
ments on this fubftance, have afcertained the following 
oo, 

. It does not melt alone by the blow-pipe, but with 
aaa to which it communicates a green colour like that of 
the emerald. 

2. It is foluble in the muriatic acid, but flowly, and in fmall 
quantity. From its folution, which is of a greenifh blue 
colour, it is precipitated white by alkalies. 

3. Itis foluble in oxygenated muriatic acid. From this 
folution, almoft colourlefs, it is precipitated of a reddith 
brown by alkalies, and of an orange yellow by nitrat of lead. 

4. It is not decompofable by ‘potath, or the carbonat of 
potafh, without the affiftance of a degree of heat which cars 
ries it to incandefcence. 

5. It may eafily be reduced by the known means. It then 
gives an alloyed mais, having only an external metallic 
afpect, ealily fufed with borax ; brittle, but hard as fteel. 


6. This mafs is exceedingly difficult to be decompofed. It — 


muft be treated: fucceffively and feveral times with potath, 
which combines with the chromic acid and diffolves it, 
and with the muriatic acid, which diffolyes the oxyd of 
iron. 


7+ Other 


+,. ~ 
She 


* 
Ws 


° 
; ‘Method of checking Decay in Trees. 307 


* Other experiments have proved the prefence in this mi- 
neral of filex and alumine; fo that C. Vauquelin and Taflaert 
believe it to be compofed of the following fubftances : 


Chromic acid - - 43 
Oxyd of iron ~ - a4ry 
Argil = - = 203 
Silex - - -— 2 


_ They ate of opinion alfo, that, the chromic acid being in 
fuffictent quantity to faturate the oxyd of iron, this araetal 
is a triple combination of the chromic acid, the oxyd of 
iron, and argil. 

8. The oxyds of chrome, er the chromic acid, may be 
employed in the porcelain manufaéture. When pure, they 
give an emerald green, more beautiful than that of copper ; 
and, mixed with lead or antimony, a canary-bird green. 


They may be employed alfo in painting, by feparating the 


acid from the iron, and combining it afterwards with differ- 
ent metallic oxyds by double affinities. 


METHOD OF CHECKING DECAY IN TREES. 
The chefinut lives a long time, and often attains to an 


‘extraordinary fize; but unfortunately the texture of its wood 


alters under certain circumftances: it becomes foft, falls 


_ into duft, a cavity 1s gradually formed in the heart of the 


tree, and this cavity, by the progrefs of the decompofition, 
becomes fti!l larger; fo that, at laft, the trunk feems to 
tonfitt of nothing but bark ; and being too weak to fupport 
the branches, and refift the violence of hurricanes, it cannot 
Jong exift. It is by fimilar changes and decompofitions of 
the ligneous principle, that trees, which have been: growing 
for ages, are feen to perifh in a very little time. 

C. Chaptal, in travelling through different parts of France, 
and particularly the Cevennes and the department of Allier, 
ebferved, that a great number of cheftnut-trees were hollow, 
and charred over the whole internal furface.. He was told 
by the inhabitants of the country, that this procefs was em- 
ployed to ftop the progrefs of the caries, which otherwife 
would deftroy the whole tree. When they obferve that this 

Rr 2 difeafe, 


308 Gravity of Tung fien.+Fluat of Argil. 


difeafe, which is very common and exceedingly fatal to the 
cheftnut-tree, begins to make any progrefs, and to excavate 
the trunk, they collect heath and other vegetables, and fet 
fire to them in the cavity, till the whole furface is completely 
charred. It happens very rarely that the tree perifhes by this 
operation, and it is always found that this remedy fufpends 
+ the effect of the caries. It is praétifed with the fame*fuccefs 
on the white oak, By comparing the effects of the cautery 
on the human body, in analogous cafes of degeneration, we 
perceive a new fimilarity between difeafes which affeét the 
living organifed beings of the two kingdoms, and between 
the remedies by which they may be checked. . 


ON THE GRAVITY OF TUNGSTEN. 


The difficulty of bringing tungften to complete fufion has 
hitherto prevented the {pecific gravity of this new metal from 
being with certainty determined. Some fixed it at 17°6, ac- 
cording to the experiments of the brothers d’Elhuyar; but 
many could not believe it to be fo confiderable. C. Guyton 
lately obtained a well-formed button, of the weight of 25 
grammes, in a three-blaft-furnace, where the intenfity of the 
fire may be carried to about 185° of Wedgewood: but this 
button having broken by the preffure of the vice, into which 
it was put in order to be fawn, there was dilcovered at its centre 
a part not agglutinated, which, by expofure to the air, {peedily 
affumed a purple colour, fimilar to that which the beft fufed 
tungtien, of fuch a degree of hardnefs as to render a file bril- 
liant, exhibits on its furface. It refults, from thefe experi- 
nients, that the {pecific gravity of the fufed portion, feparated 
from that which was only fufed imperfectly, was 8°3406 ; 
that the infufibility and brittlenefs of this metal Jeave no 
other hopes of applying it to the arts, though there are abun-. 
dant mines of it in France, but by nuxing it with other me- 
tals, or by the property difcovered in its: oxyds of yielding 
fixed colours, and, fixing vegetable colours. 


FLUAT OF ARGIL. 


C. Vauquelin has received from, Denmark a white lamel- 
lated mineral brought-from Greenland, which proves to be 
5 fluat 


a a ee 
a a a os Foe 


a ee ee a ee ee ee ee ee ee 


<— 


Aftronomy —Monument.—Subflitute for Coffee. 309 


fluat of argil, an earthy neutral falt never before found in a 
natural ftate. 
ASTRONOMY. 

C. Lalande has lately prefented to the National Inftitute 
an account of his obfervation of the laft oppofition of Mars, 
with the calculations on that fubject; and by comparing it 

‘with that of 1790, he has found that only 58 feconds are to be 
deduéted from the place of the aphelion of Mars, employed 
in the laft edition of his Aftronomy. He announces a large 
work on this planet by C. Lefrancais-Lalande, his nephew. 

C, Lalande has alfo given the calculation of eclipfes of the 
fun or ftars obferved for fome years, to deduce from them the 


- pofition of different cities. He has-found Hamburgh to be 


30 9” from Paris; Cobourg 34’30”; Mulheim 21’ 20’ 
Halle 38‘ 28”; and Konigfberg 1" 12’ 35”. 


MONUMENT TO LINNEWS. 
A monument has lately been erected in the cathedral of 
Upfal, to the memory of the great Linneus. It confifts ¢n~' 
tirely of the porphyry of Elfwedal; is properly a pedeftal 


_ in the form of an altar, the fleps of which are of the brown: 


fione of Oeland; and fupports a medallion containing a buft 
ef Linneus. The following is the infcription : 


Caroto A LINNE, | 
BoTAaNICORUM PRINCIPI, 
Amici ET.DISCIPULI. 
.M,DCC,XCVIIII. 


SUBSTITUTES FOR COFFEE. 


Count‘ von Burgfdorf has lately laid before the Royal Aca- 
demy of Sciences at Berlin, famples of coffee prepared from 
the folid parts of the beet-root, after the faccharine juice has 
been expreffed. 

After the moft careful examination of all the fubftitutes for 
coffee hitherto employed, the Academy of Sciences at Peters- 


_ burgh has made known that the acorn is the beft, as it pof- 
- feffes, when proper means are ufed to communicate to it the 


gily properties, all the requifite qualities of coffee. To com- 


‘municate thefe oily properties, the following procefs is re- 


commended : 


310 Subftitute for Bark—Galls.—Travels in Africa. 
commended: When the acorns have been toafted brown, add 
frefh butter, in fmall pieces, to them while hot m the ladle, 
and ftir them with care, or cover the ladle, and fhake it in or- 
der that the whole may be well mixed. - By thefe means you 
will obtain the beft and moft harmlefs fubftitute for coffee 
hitherto employed. 


SUBSTITUTR FOR TINCTURE OF BARK. 


Dr. G. F. C. Fuchs, teacher extraordinary of medicine at 
Jena, has prepared from the ripe fruit of the horfe cheftnut, 
Aefculus bippocaflanum Linn. when divefted of the hutks, 
an extraét, which, according to his experiments, may be 
ufed, perhaps, inftead of the expenfive extraétum chine, fince 
the bark of this tree has been long known as a fubftitute for 
cinchona. 


SUBSTITUTE FOR GALLS. 


A German apothecary, named Trémer, has lately difcos 
vered, that the excrefcences or knots on the roots of young 


oaks may be ufed as a fubftitute for galls. Thefe exoh@ecnhed 


are produced, in the fame manner as the galls, by an infect, 
which, after pricking them, depofits its eggsin them. With 
vitriol ae iron, in the fame proportion as galls, they give a 
beautiful black ink, and may be ufed alfo in dyeing. In the 
fpring, thefe excrefcences may be found in great winbers on 
the fmall roots of the oaks, particularly on the fouth fide, of- 
ten about a hand’s-breadth below the earth. Thofe found in 
fummer have, for the moft part, {mall apertures, capable of 
admitting a moderate-fized needle, but they are no longer 
filled with eggs. At this period they are more woody, and 
not fo good; and-therefore they cught to be colleCled in the 
fpring. 
TRAVELS IN AFRICA. 

Mr. Horneman, whom we-fome time ago announced to 
have fet out with the view of exploring the interior of Africa, 
has written a letter'to Sir Jofeph Banks, from Tripoli. He 
had travelled from Cairo, in Egypt, througl the Lybian-. a" 
fert, to Fezzan, the largeft Oafis in the Great Sahara ; 
route hitherto unexplored by any European, whofe me 
have 


Travels in Africa.—Cementing of Broken Glafs. 31% 


have been communicated to the public. In the journey from 
Cairo to Fezzan, he halted at Sewah, which, from the no- 
tices of Mr. Brown, fome months ago, had been clearly af- 
certained to be the Oafis of Ammon. 

Mr. Horneman’s new obfervations, made at his leifure on 
the {pot, now place this matter beyond all manner of doubt. 
Mr. H. was too late this feafon for the caravan that goes 
from Fezzan to Soudan, compreheuding under that name 
Hourfes, Cafhnou, Burnou, the great kingdom near the Ni- 
ger. Meanwhile he has fent from Tripoli, hy another con- 
veyance, not yet arrived, the journal of his prefent.travels 5 
and there is every reafon to hope that he will accomplith his 
great undertaking of vifiting the unknown central regions of 
Africa, efpecially from the following occurrences mentioned 
in his letter :—He was followed from Sewah by a large party 

_ fent to feize him, on fufpicion of his being a French{py. But 
his manners and behaviour were fo completely Moflem, and 
he approved himfelf {fo thoroughly mafter of the Koran, that 
he was releafed with bleilings and alms as a good muffulman, 
and fent forward on his journey, 


CEMENTING OF BROKEN GLASS, 


C. Pajot, of Charmes, Jately tranfmitted to the Philo+ 
matic Society and the National Inftitute, { fmall bits of glafs of 
different qualities, which he had joined and foldered fo firmly 
that the glafs would rather break clofe to the joining than in 
the a€tual place. The form of the fraéture does not at all 
prevent the operation. The line of junétion is fcarcely dif- 
cernible, and in fome places not vifible. C. Pajot has not 
made his procefs known. 

_ C. Swediaur informed the Society, that a perfon named 
Hollenweger, about twelve or fourteen years ago, had in his 
prefence, and that of Lavoifier and Meunier, performed 
fome experiments, by means of which he joined in a folid 
manner, fo ag to make the junction hardly vifible, fragments 
of blown glafs. 

is Chaptal faid alfo that fome perfon had fhewa him, 
about fifteen years ago, a glafs bottle, the neck of which 

"was fo perfeétly foldered to the glafs ftopper, that, when cut 
through, the circle of junction was {carcely perceptible. The 
bottle 


312 Death. 


bottle contained liquor of flints, and had Jain on its fide for 
along time. ‘ After feeing this fa&t, faid Chaptal, I con- 
ceived the poffibility of foldering together two plates of glafs. 
I explained my ideas on this fabject, and fhewed the bottle, 
in my public leétures; and I am of opinion, that, by gra- 
dually withdrawing the diffolving alkali, it might be poffible, 
to unite fuch plates.’’’ 

Before we difmifs this article, we beg leave to remark, that 
there appears to be nothing fo wonderful in joining broken 
pieces of glafs, in the way above deferibed, as to juftify Pa-— 
jot in concealing. the procefs. A little reafoning will lead 
any one to it. All that is neceffary is to interpofe, between 
the parts; a glafs ground up like a pigment, but of eafier fu- 
fion than the pieces to be joined, and then expofing them to 
fuch a heat as will fufe the cementing ingredient, and make 
the'pieces agglutinate without being themfelves fufed. A 
glafs fit for the purpofe of cementing broken pieces of flint 
glafs, may be made by fufing fome of the fame kind of glafs, 
previoufly reduced to a powder, along with a little ved lead 
and borax, or with the borax only, 

DIED. 

At Edinburgh, on the 6th inft. Dr. Jofeph Black, one of * 
the Phyficians | to his Majefty for Scotland, Profeflor af Che- 
mittry in the Univerfity of Edinburgh, and a Member of the 
different refpectable Medical and Literary Societies in Europe. 
The noble fcience of Chemiftry has received many valuable 
improvements and elucidations from the genius and induftry 
of the learned Dr. Black, which will tranfinit his name with 
honour to the lateft pofterity. 

His papers were found in fuch perfeé order by his execu- 
tors, that we underftand they intend {peedily to publifh them, 
with a life of the author, 


, Erraia in our Laf. 
Io the defcription of Mr. Howard’s Furnace, laft line, (p. 192,) for 
Wirdlor read fire bricks, 
Page 198, line 26, for ¢ypqn/ read /ympanz, 
In the defcription of the monument to Count Rumford, p- 206, line 7, 


read 
At the creative glance of Charles Theodore, 


Rumford, the friend of mankind, &c. 


THE 


PHILOSOPHICAL MAGAZINE. 


%ANUARY- 1800. 


1. A Communication from GeoRGE PEARSON; M.D: 

FOR. S. &c. Phyfician to St. George’s Hofpital, &c. con= 

cerning the Eruptions refembling the Small-Pox, which 
Sometimes i iri in i Inoculated Vaccine Difeafe. 


For reafons, the explanation. of which. would lead into 
too long a detail, and which, indeed, cannot be given with 
perfed propriety in this fheet; I feel myfelf compelled to 
publifh fome obfervations concerning the eruptions which 
appear, in fome inftances, in the cow- “pock by inoculation. 
Although the new inoculation in the prefent. year has 
been, I think, fufficiently extenfive to manifeft the advan- 
tages of it over that for the fmall-pox, fo that it is not likely 
to be ever totally laid afide; yet the unexpected appear- 
ance of eruptions has inclined many perfons to be of opinion 
that no beneficial confequences can be produced by this prac- 
tice, or, at leaft, that fuch confequences at beft feem to be 
problematical. It may be ufeful to obferve, that fome of the 
Advocates for the cow-pock inoculation contend, that erup- 


_ tions are never produc ed by it; accordingly, they affert, that, 


in thefe eruptive cafes, the diforder was not the cow-pock, 


but the fmall-pox; the variolous poifon. having either, been 


inferted inadvertently, or the conftitution having been af- 
Vou, V. Sf ‘fected 


314 On the Eruptions which fometimes appear 


feéted by it cafually. To juftify what is advanced, it is in- 
cumbent on the Affertors either to prove that fuch errors have 
been committed, or at leaft they ought to be able to oppofe 
equally extenfive experience to that of the adverfe party: for no 
found reafoner will confider opinions, which are only founded 
in conjecture, to be demonftrated truths. I will not, how- 
ever, take upon myfelf the unrequired tafk of attempting to 
vindicate others from the above charges; but I fhall only 
perform a duty in ftating the refult of my own experience 
with regard to the point in queftion; conceiving that by this 
means the truth may be brought to light, if aided by the evi- 
dence from experience of future inquirers. 

In the courfe of my pra¢tice the latter end of February, 
and in March following, I diftinétly recolle& four cafes 
in which I firft faw eruptions from the vaccine inoculation 
refembling fo much thofe of the fmall-pox, that I fhould not 
have hefitated to confider them as belonging to this difeafe, if 
I had not excited them by a different poifon from the vario- 
lous. I obferved, however, at that time, fome appearances 
of thefe eruptions different from thofe which ufually oecur in 


the fmall-pox. Almoft all the eruptions, in the ftage of defic-- 


cation, afforded fhining, fmooth, black or reddifh-brown fcabs ; 
very few of them having previoufly fuppurated. Finding, in 
two other inftances, that the matter from the inoeulated puftule 
of thefe patients produced a fimilar eruptive diforder, and alfo 
the fame being the event in the practice of two or three of my 


correfpondents, whom IJ had furnifhed with matter from the - 


above eruptive cafes, I from that time ufed matter only from 
the cafes in which no eruptions appeared. After this precau- 
tion, no eruptive cafes refembling the fmall-pox occurred in 


my practice during the whole of Jaft fummer and the prefent. 


winter. I fay, no cafes occurred refembling the fmall-pox ; 
but certainly eruptions, in number from a fingle one to about 
a dozen, which were large, red, hard pimples, with little or no 
lymph, and never with any pus, occurred, probably, in one 
cafe out of twenty or thirty. Thefe fpots, fo unlike the fmall- 


pox, produced no trouble; and were of fuch a fhort duration, _ 


that, when I {peak of eruptions, I do not include them in the 
number; I include in the account thofe only in which the 
¥ eruptions 


in the inoculated Vaccine Difeafe. 315 


eruptions refembled the fmall-pox: nor do I reckon among 
the eruptive cafes thofe in which, now and then, a rafh broke 
out about the 14th day after inoculation; and which was as 
troublefome as the Urticaria. My experience, then, with re- 
fpeé&t to the cafes of eruptions being diminifhed in number 


_ by avoiding inoculation with matter of fimilar eruptive cafes, 


coincides with Dr. Woodville’s; and confirms what he has 
already fo ufefully communicated to the public. It was ob- 
vious to fufpect, on the firft occurrence of the eruptive cafes, 
that variolous matter, in an unobferved way, but from fources 
which could not even be conjectured, had been introduced 
into the conftitution inftead of the vaccine poifon. This 
conjecture, in fpite of the cleareft evidence of fenfe refpect- 
ing the nature of the matter ufed, received fome countenance 
from the non-appearance of eruptions as above ftated; but, 
from the occurrence of fuch cafes, in the practice of other 
Inoculators, in the laft autumn and this winter, I think it 
is very unreafonable to doubt any longer, that, either on 
account of peculiar ftates of the human animal ceconomy, or 
on account of fome co-operating agents, the genuine vaccine 
poifon does now and then produce a certain variety of the 
cow-pock, characterifed by the appearance of puftules, like 
thofe of the variola. I have good evidence alfo to fhew, that 
even in the hands of thofe very Inoculators, who a little time 
ago would not allow that the vaccine poifon could produce 
eruptions, fuch cafes have lately“occurred. 

In the month of O&tober laft I inoculated a child two 
years of age with the vaccine poifon. The original mat- 
ter, which had produced this matter, I took from the cow in 


. March laft; fince which time the vaccine difeafe had been 


excited by it, in my hands, in a great number of patients. 
The vaccine difeafe took place with the ufual appearances, in 
the inoculated part, and affected the whole conftitution in the 
ordinary manner; but a few eruptions broke out on the fe- 
cond or third day after the flight fever; they were, however, 
only the red large pimples above mentioned, not at all like 
the fmall-pox. Mr. Keate carried matter from this child to 
Brighthelmftone, where Mr. Barret inoeulated ¢wo children, 
who took the difeafe ; and from one of thefe Mr. Keate ino- 

Sfa2 culated 


516 On the Eruptions which fometimes appear 


culated ghree children. They all had the ufual fever about 
the eighth day, and all had a number of eruptions, except 
one, which had only five or fix, and thefe dried on the fifth 
day. This laft cafe was probably that which Mr. Keate in- 
forms me had, in the inoculated part, the genuine vaccine 
puftule; but in all the others Mr. Barret obferved that in 
the inoculated part the puftule was ragged at the.edges, and 
flat, more refembling the variolous puftule, Matter from 
thefe patients was fent to Petworth, where Mr. Andre in- 
forms me he inoculated with it fowrtgen children. They all 
took the' difeafe, and had eruptions like the variolous. Three 
children at the breaft had from ¢hree to twelve puftules. 
The remaining e/even children had from fifty to feveral hun- 
dred eruptions. The ftate of the arms, and the characters of 
the puftules of the inoculated part, are not mentioned. None 
of the above patients died, nor is any mention made by Mr. 
Keate, Mr. Barret, and Mr. Andre, even of any apprehenfion 
of danger. Dr. Thornton fent me lately a cafe with eruptions, 
produced by matter which I originally took from a cow. Ac- 
cording, then, to experience, we draw thefe conclufions :— 
t. That in certain conftitutions, or under the circumftances of 
certain co-operating agents, the vaccine poifon produces a dif- 
eafe refembling the fmall-pox; and of courfe the puftule in the 
inoculated part is very different from that of the vaccine pock 
ordinarily occurring, and the eruptions refemble yery much, 
if not exactly, fome varieties of the fmall-pox. 2. That in 
fome inftances thefe eruptions have occurred although the 
inoculated part exhibited the genuine vaccine puftule, 3. That 
the matter of fuch eruptive cafes, whether taken from the 
inoculated part, or from other parts, produces univerfally, or 
at leaft eenerally, fimilar eruptive cafes, and has not, I believe, 
been feet to go back, by paffing through different conftitu- 
tions, to the {tate jn which it produces what is called the ge- 
nuine vaccine difeafe. 4. That eruptions, of a different ap- 
pearance from variolous ones, fometimes occur jn the true 
cow-pock, 

Now, whether the vaccine poifon, when it produces thefe 
cafes refembling the fmall-pox, has really become, by com- 
pofition or decompofition, variglous matter, is undetermined, 


if. 


pets ia =, 


— 


ee ee ee 


=—s- 
ee 


ee ee 


~~ 


EEE a Pree eS ee 


in the inoculated Vaccine Difeafe. 317 
tf this fhould be found to be the cafe by future experiments, 


- {till we mutt confider the two potions as of diftin&tly different 


fpecies, on account of the different characters of the puftule 


‘in the fmal]-pox and cow-pox; although, as juft faid, by the 


combination of fome other fubftance with the cow-pox poi- 
fon, or by the feparation of fome one of the conftituent in- 
gredients of this poifon, the variolous poifon may be pro- 
duced. To illuftrate this theory let it be confidered, that 
magnefia and fulphate of magnefia are different fpecies of 
fubflances ; although they agree in fome of their principal 
effects on the human conftitution, and in other properties ; 
but, by the union of magnefia with fulphuric acid, it becomes 
fulphate of magnefia. Or the illuftration may be given con- 
verfely. As, then, we have diftin@ denominations for thefe 
two fubftances, fo we ought to have them for the two poi- 
fons, and the two different difeafed {tates they produce, name- 
ly, the cow-pox and the fmall-pock. Accordingly, Dr. Odier, 
of Geneva, whofe powers as a Dialectician, and whofe acute- 
nefs as a Philologer, ‘I can atteft from the period of his aca- 
demical ftudies, has ‘ baptifed”? (to pfe the language of Dr. 
De Carro,) the new difeafe La Vaccine, or Vaccina, rejecting 


the abfurd name of the Englith, variole vaccine. 


But, to return to the immediate queftion under difcuffion, 
granting that eruptions are liable to be produced by the ino- 
culation of the cow-pock, what difference ought this accident 
to make in our eftimate of the value of the new practice, 
from the eftimate on the fuppofition that no fuch cruptions 


would occur? I apprehend the value is hereby depreciated, 


- 


but not to fuch a degree as to create any reafonable apprehen- 
fions of the failure of the Vaccine Inoculation in fuperfeding 


and extinguifhing the fmall-pox. Becaufe, 


mee Tt. the precaution be taken of avoiding the ‘adiularias 


with matter from eruptive cafes, as far as T have feen, not 
above one cafe, with variolous-like eruptions, will be pro- 


duced among 200 inftances of inoculated cow- pox. 

2. Thefe eruptive cafes are, as far as I have obferved, like 
the ordinary kinds of inoculated fmall-pox. 

3. I have feen no disfigurations of the fkin from this va- 


. el of cow-pox; but I think it jut to acknowledge that, 


from 


3r8 Otjfervations refpecting the Earthquake 


from the experience I have had, no practitioner can anfwer — 


for fuch cafes not occurring in any inftance, and as danger 
is always in proportion to the number of eruptions, which 
number no one can pretend to limit, it is evident that the 
chance of life during this difeafe is leffened, although but a 


very little. Provided this flatement be made to the patient, it — 


does not appear to me that the fact of the liability to eruptions 
‘ought to impede the progrefs of the Vaccine Inoculation; 
but if, on the contrary, the patient is affured that fuch erup- 
fions will not occur, there is good ground for the practice 
falling into difcredit, or at leaft for many perfons, with rea- 
fon, being difeontented. 

After this réprefentation of an unfavourable part of the 
hiflory of the cow-pock, it is confolatory to be able to coun- 
terpoife it with fome new faéts, which, hke that of the erup- 
tions, have been difcovered in the courfe of further experi- 
ence. It now appears that a perfon who has had the fimall- 
pox, is not fufceptible of the cow-pox by imoculation* ; 
nor is a perfon fufceptible of the conftitutional affection from 
_ the cow-pox poifon more than once. On the whole, then, 
we have gained perhaps as much as we have loft finee the 
publication of the original account: and unlefs fome new 
adverfe facts fhall be difcoyered, and confiding that the public 
will adopt a practice which is fo manifeftly to their intereft, 
the change effected in the pra¢tice of medicine will be fo 
eminently memorable, that the introduétion of the Vaccine 
Inoculation mufl become an epoch in the biflory of phyfic. 


I. Obfervations refpeéiing the Earthquake which took place 
in Peru in the year 1797. By M. CAVANILLES*. 


¢ en are reckoned to be more than fixteen volcanoes 
in the kingdom of Quito which are in a-continual ftate of 
eruption, and which throw up thick vapours, often mixed 


* The cafes of milkers with chopt hands being repeatedly affected by 
the cow-pox poifon in the cafval way, wheter they had undergone the 
fmall-pox or not, probably occafioned the error of the conclufions here 
alluded to. 

+ From the Yournal de Phyfique, Fractidor an. 7, b 

p wil 


, 


. 
—— —— 
ee ee oe 


Se Pa 


8 Se ey ee 


7. 


-% 
a 


POS Sige ae 


4 


PR ei 


om. 
— 


tg 


a 5 
; 


~ 


ewbich took place in Peru in the Year1797. 39 


_ with flames, either from their craters or through their lateral 
fiffures. In the midft of the moft profound calm there is 
frequently heard a dreadful bellowing noife, the forerunner 
of earthquakes, to which this part of the world is often ex- 
pofed. After the year 1791, this noife was frequently heard 
in the neighbourhood of the mountain of Tunguragua. An- 
tonio Pineda and Née, the ‘two naturalifts employed in the 
expedition round the world, when examining the declivity 
of this volcano, the lava of which had been hardened more 
by the internal fire than by the ardour of the fun, were ftruck 
with terror by the horrible found which they heard, and the 
heat which they experienced. Pineda, that valuable member 
of fociety, whofe premature death is ftill deplored by the 
friends of fcience, foretold that a terrible eruption was pre- 
paring in the mountain of Tunguragua; and his conjectures 
were confirmed by the event. On the 4th of February 1797, 
-at three quarters paft feven in the morning, the fummit of 
the volcano was more free from. vapours than ufual; the in- 
terior part of the mountain was agitated by frequent fhocks, 
and the adjacent chains burft in fuch a manner, that in the 
fpace of four minutes an immenfe tract of country was con- 
vulfed by an undulating movement. Never did hiftory relate 
the effects of an earthquake fo extraordinary, and never did 
any phenomenon of Nature produce more misfortunes, or 
deftroy a greater number of human beings. A number of . 
towns and villages were deftroyed in a moment: fome of 
‘them, fuch as Riobamba, Quero, Pelileo, Patate, Pillaro, 
were buried under the ruins of the neighbouring mountains ; 
and others in the jurifdictions of Harnbata, Latacunga, 
Guaranda, Riobamba, and Alaufi, were entirely overthrown. 
Some fuftained prodigious lofs by the gulphs which were 
formed, and by the reflux of rivers intercepted in their 
courfe by mounds of earth; and others, though in part 
faved, were in fuch a fhattered ftate as to threaten their total 
‘tuin. The number of perfons who perifhed during the firft 
and fucceeding fhocks are eftimated at 16,000. At ten 
‘o’clock in the morning, and four in the afternoon, the fame 
day, (February 4,) after a dreadful noife, the earth was again 
agitated with great violence, and it did not ceafe to fhake, 
though 


320 Ey eee refpetting an Ear thouake i in Port 


though faintly, for the whole month of February and March ; 4 
but, at three quarters paft two in the morning of the 5th of : 
April, the villages already ruined were again expofed to fuch ~ 
violent fhocks as would have been fufficient to deftroy them. ~ 
This extraordinary phenomenon was felt throughout the ex- 
tent of 140 leagues from eaft to weft, from the fea as far as 
the river Napo; and without doubt farther, for we are little © 
acquainted with thefe difiricts which are inhabited by the- 
favages. The diftance north-eaft and fouth-weft between ~ 
Popajan and Piura, is reckoned to’ be 170 leagues; but in ~ 
the centre of that diftri€t, 1 degree 16°6 from thefe places, 
is fituated the part totally deftroyed, and which comprehends 
forty leagues from north to fouth between Guarandam and 
Machache, and twenty leagues from eaft to wefi. But, as 
if an earthquake alone had not been fuffiicient to ruin this 
fertile and populous country, another misfortune, hitherto 
unknown, was added. .The earth cepened, and formed im- 
menfegulphs; the fummits of the mountains tambled dewn 
into the’ valleys, and from the fiffures in their fides there 
iffued an immenfe quantity of fetid water, which in a little 
time filled up valleys a thoufand feet in depth and fix buns 
dred in-breadth. » It covered the villages, buildings, and in- 
habitants ; choaked up the fources of the pureft fprings, and, 
being condenfed by deficcation, in the courfe of a few days, 
into an earthy and hard pafte, it intercepted the courfe of 
rivers, made them flow backwards for the {pace of eighty- 
feven days, and converted whole difiricts of dry land into 
lakes. Very extraordinary phenomena, whieh will doubtlefs 
be one day mentioned ‘in -hiftory, occurred during thefe 
earthquakes; I {hall, however, content myfelf with men- 
tioning only two of them. At the fame moment that the 
earth {hook, the lake of Quirotoa, near the village of In- 
filoc, in the jurifdiction of Lacatunga, took nee and the 


vapour which rofe from it fuffocated the cattle and flocks ~ 


that were feeding in the neighbourhood. Near the village 
of Pelileo, a large mountain named Moya, which was over- 
turned im an inftant, threw out a prodigious ftream of the. 
before-mentioned thick fetid matter, which deftroyed and 
covered the miferable remains of that city, Naturalifts will 

* one 


Tanning Principle and Gallic Acid in Barks. 424 
one day find, in thefe ravaged countries, objects worthy of 
their refearches. Fragments of the minerals and earths of 
Tunguragua are about to be tranfported to Spain: but it is 
notin fuch fragments that we ought to fearch for the caufé 
of thefe furprifing phenomena; we miuft vifit the country it- 
felf, where this conflict of the elements took place, and where 
the ruins it occafioned are {till to be feen *. 


HI. Experiments to determine the Quantity of Tanning Prin- 
ciple and Gallic Acid contained in the Bark of various 
Trees. By GeorGe Biccin, Efg.t 


Tur bark of trees contains the aftringent principle called 
gallic acid, and alfo that principle which has a peculiar afhi- 
nity to the matter of fkin, and which, from the ufe to which 
it is applied, is called the tanning principle: But, in the 
prefent mode of tanning, bark is applied in ma/s to the 
fkins ; confequently, doth principles are applied. It remains 
for examination, whether both principles are ufeful in the 
procefs of tanning; for, if they are not both ufeful, probably 
6ne is detrimental. 

To a nobleman, whofe zeal on every occafion by which | 
the fciences or arts may receive illuftration or improvement, 
is eminently confpicuous, and to whofe public energy, as 
well as private friendfhip, I feel myfelf much indebted, to 
his Grace the Duke of Bedford, I owe the means of profé- 
cuting fome experiments on this fubje&t. His Grace, by 
collecting a variety of barks, at Woburn, gavé me an op- 
portunity of making fome experiments to afcertain thé quan- 
tity of tanning principle and gallic acid each bark contained, 
For that purpofe I made ufe of the following methods, ac- 
eording to the principles laid down by M. Seguin :— 

By diffolving an ounce of common glue in two pounds of 
‘boiling water, I procured a mucilaginous liquor, which, as 
‘H, contains the matter of fkin in folution, is a teft for the 


* The volcano of Tunguragua oceafioned an earthquake in 1557 
# From the Philoophical Tranfattions of the Royal Society of Londop. 
Vor. V. Tf tanning 


322 On the Tanning Principle and Gallic Acid 


tanning principle. By a faturated folution of fulphat of iron, 
T obtained a teft for the gallic acid. 

I then took one pound of the bark I meant to try, ground 
as for the ufe of tanners, and divided it into five parts, each 
part being put into an earthen veflel. To one part of this 
bark [ added two pounds of water, and infufed them for one 
four, Thus I procured an infufion of bark, which I poured 
on the fecond part of the bark, and this {trengthened infufion 
again on the third part, and fo on to the fifth. But, as a 
ceMtain portion of the infufion will remain attached to the 
wood of the bark after the infufion is poured or drawn off, I 
added a third pound of water to the firft part, and then fol- 
lowed up the infufion on the feveral parts till the three pounds 
of water, or fo much of them as could be {eparated from the 
bark, were united in the fifth veflel; from which I generally 
obtained about one pint of {trong infufion of bark *. 

To a certain quantity of this infufion, 1 added a given 
meafure of the folution of glue, which formed an immediate 
precipitate, that may be feparated frony the infufion by filter-. 
ing paper. When dried, it is a fubftance formed by the che- 
mical union of the matter of {kin with the tanning principle, 
and is, in fact, a powder of leather. By faturating the infufion 
with the folution of glue, the whole of the tanning principle 
may be feparated by precipitation. 


For the Gallic Acid. 


To the pound of bark left in the earthen veffels, and al- 
ready deprived of its tanning principle by thefe gwick infu- 
fions, I added a given quantity of water, to procure a {trong 
infufion of the gallic acid, which requires a longer time, 
(lay forty-eight hours.) This infufion, when obtained puref, 
affords little figns of the prefence of the tanning principle, 


* The fpecific gravity of this infufion was afcertained by; an hydre- 
meter Whole gradations are inverfe to thofe of a f{pirit hydrometer. 

+ Itis hardly poffible, from the intimate connection of the two prin- 
ciples, to feparate them entirely by infufion: in the infufion of tanning 
principle, there will always exift a little gallic acid; and, in an infufion 
of gallic acid, a little tanning principle will commonly be prefent, unlefs 
the infufion of gallic acid is yery weak, and procured by a third or fourth 
wateripg. 

when 


contained in various Barks. 323 


when tried by the teft of the folution of glue; but, with the 
folution of fulphat of iron, it gives a {trong black colour, 
(the common black dye,) which differs in denfity according 
to the quality of the bark: this may be further proved, by 
boiling a fkain of worfted in the dye, by which the grada- 


tions of colour will be very perceptibly demonftrated. 


Having thus obtained a point of comparifon; by making 
a fimilar infufion, under fimilar cireumftances, of any bark, 
or vegetable fubftance, and paying ftrict attention to the fpe- 
cific gravity of the infufion, the quantity of precipitate of 
leather, and the denfity of colour produced by given quanti- 
ties of one or the other teft, the refult will be, a comparative 
ftatement of the refpective powers of any bark, or vegetable 
fubftance. This comparative ftatement I conceive to be fuf- 
ficient for all commercial purpofes. 

As oak bark is the ufual fubftance employed in the trade 
of tanning, if a quantity of tanning principle is found to be 
contained in any other bark or vegetable, the commercial 
utility of that bark or vegetable may be determined, by com- 
paring its quantity of tanning principle and price with thofe 
of oak bark, 

For an accurate chemical analyfis, I have tried a variety of 
acids, and fimple and compound affinities; and, having pur- 
fued the above experiments at the fame time that I was em- 
ployed on fome in dyeing, I found the muriat of tin (the 
method of ufing which is defcribed by Mr. Prouft in the 
Annales de Chimie,) very convenient. A folution of it béing 
added to the infufion of bark, forms a precipitate with the 
tanning principle, leaving the gallic acid fufpended: the pre- 
cipitate is of a fawn colour, and is compoled of tanning prin- 
ciple and oxydated tin. 

By thefe means I have been enabled to form a compara- 
tive feale of barks; which, however, I do not produce as 
accurate. Oak bark, in its prefent fiate, as procured for 
commercial purpofes, differs very much in quality, from ac- 
cidental circumftances: the feafon of the year in which it ig 
collected occafions a flill more important difference, confe- 
quently the fcale now produced muft be very imperfect ; 


but [am of opinion, that, by the purfuits of {cientific men, 


faa who 


ren 


324 Tanning Principle and Gallic Acid in Barks. 
who may be inclined to inyeftigate this fubject more ney 
a very accurate feale may hereafter be formed. 

In the following feale, I bave taken Sumach as the moft” 
powerful in the comparative ftatement ; leaving, however, a 


jew degrees for a /uppofed maximum of tanning principle, 


which I reckon twenty. 


SCALE OF BARKS, 


Tanning pr inciple, 


G: Mic acid, Tanning prin- (in grains,) from 
by colour.’ ciple, by by- half a pint of infus — 

: “aR 4 drometer, fion and an ounce 

Bark of ‘ of folution of gle. 

Rl 8 1829) este ty 2,1 28 | 
Oak, cut in winter 8 yy i 30 
Horfe cheftnut - 6 252 30 
Beata abr ten 2,4 31 
Willow (boughs) 8 24 31 
Pricey Ae ep aie ti TY, 330 41 
Plum-tree - - 6- 4,0 58 
Willow (trunk) - 9 ‘4,0 52 
evcaitioré =) = 6 Be 53 
Bir@l! Pye Ss) 'Sa4 4yI 54 
Cherry-tree -. + ° 8 45 59 
Sallow)< F)3. LoRg 4,0 59 
Mountain afh - 8 4,7 60 
Pooldr’) 20-9" 8 6,0 76 
Hazel. - = = 9 6,3 79 
ARey ras ao Oe Gy 6,6 82 
Spanilh cheflaut. - 10 *G.0 : g8 

Snisoth oak’ == to 9,2 104 ; 
Oak, cut in [pring 10 950 108 
Huntingdon or Lei- sh 
cefter willow .- 10 10,1 10g 
Sumach- - -~"- 34 16,2 - 158 


It is to be obferved, that the barks do not keep any re- 
fpeStive proportion in the quantity of gallic acid and tanning. 
principle contain-d in each; which is an evidence of the 


* The i: fufion of elm was fo loaded with mucilage that it was with 
@. fficuity £ I could Leparate the tanning principle, or try the fpecific gravity. 


J diflinéinefs 


reek 
. * . ° 
‘ ‘ 


On ihe Grecian Method of dyemg Cotton Yarn Red. 3 325. 


diftininefs of principle, and may perhaps open a new field 
for faving oak bark in dyeing, as the willows, fallow, afh, and 
others, produce a very fine black. It is alfo worthy of ob- 
fervation, that the quantities of gallic acid and tanning prin- 
ciple do not differ in egual proportions between the winter 
and fpring felled oaks. This faét may lead to the diferimi- 
nation of the proper time for cutting; which is, probably, 
when the fap has completely filled and dilated that part of 
the vegetable intended for ufe. This: will make a difference 
in the feafon of cutting oak, elm, and other trees, fhrubs, &c, 
Leaves fhould be taken when arrived at their full fize, and 
then dried under cover; for, as the tanning principle is fo 
foluble, and the fub{tance that contains it fo thin, (in a i) 
the dew alone might diffolve it. 

Finally, as the gallic acid does not feem to combine ik 
the matter of fkin, and as its aftringency will corrugate the 
furface, we may, I think, conclude, that its prefence in tan- 
ning is not only ufelefs, but detrimental. 


Sen 


IV. Extrad of a Memoir on the Grecian Method of dang 
Cotiou Yarn Red. By C. Fevix*, 


Th AT beautiful red dye given to cotton in the Ottoman 
empire, is known in Europe under the name of Turkey red, 
Levant red, or Adrianople red. As it is believed among us that 
this colour refults chiefly from the proceffes employed in the 
dycing, I fhall give an account of thofe followed in the Gre- 
cian manufactories. It muft, however, be obferved, that im 
thefe manufactories the workmen dye at one time a mafs of 
fkains weighing thirty-five occas; each occa being equal to 
about fifty ounces. 
_ The firft procefs is that of cleaning the cotton, for which 
_.purpofe three leys are employed; one of foda, another of 
‘afhes, anda third of lime. The cotton is thrown into a tub, 
and moiftened with the liquor of the three leys in equal 
quantities ; it is then boiled in pure water, and wathed in 
funning water. 


* From the. Annales de Chimie, No: 92. 


The 


326 EwiraG of a Memoir on the 

The fecond bath given to the cotten is compofed of foda 
and fheep’s dung diffolved in water. To facilitate the folution. 
the foda and dung are pounded in a mortar. The proportions 
of thefe petedients employe ed, are, one occa of dung, fix of 
foda, and forty of water. When the ingredients are well 
mixed, the liquor expreffed from them is {trained, and being 
peed into a tub, fix occas of olive oil are added to it, bask 
the whole is well ftirred till it becomes of a whitifh colour, 
hike milk. The cotton is then belprinkled with this water, 
and when the fkains are thoroughly moiftened, they are 
wrung, preffed, and expofed to dry. The fame bath muft 
be repeated three or four times, becaufe it is this hquor 
which renders the cotton more or lefs fit for receiving the 
dye. Each bath is given with the fame hquor, and ought 
to continue five or fix hours. It is to be obferved that the 
cotton, after each bath, muf{t be dried without being wafhed, 
as it ought not to be rinfed till after the Iaft bath. The cot- 
ton is then as white as if it had been bleached in the fields. 

The bath of fheep’s dung is not ufed in aur manufactories3 
it is a practice peculiar to the Levant. It may be believed 
that the dung is of no utility for fixing the colours ; but it fs 
known that ‘this fubftancé contains a great quantity of vola- 
tile alkali, in a difengaged ftate, which has the property of 
giving a rofy hue to the red. It is therefore probable that it 
is to this ingredient that the red dyes of the Levant are in- 
debted for their fplendour and vivacity. This much, at any 
rate, is certain, that the Morocco leather of the Levant Is — 
prepared with dog’s dung; becaufe it has been found that 
this dung is proper for heightening the colour of the lack, 
The bath of dung is followed by the procefs of galling. 

The galling is performed by immerfing the cotton in a 
bath of warm water, in which five occas of pulverifed galt- 


nuts have been boiled. This operation renders the cotton 7 
more fit for being faturated with the colour, and gives to the — : 


dye more bady and ftrength. After the galling comes alum- 
ing, which is performed twice, with an Steere of two days, 
~ and which confifts in dipping the cotton into a bath of water 
in which five occas of alum have been infufed, mixed with 
five occas of water alcalifed by a ley of foda, The aluming ~ 
mul 


Grecian Method of dyeing Cotton Yarn Red. 327 


muft be performed with care, as it is this operation which 
tiakes the colouring particles combine beft with the cotton, 
and which fecures them in part from the deftructive action 
of the air. When the fecond aluming is finifhed, the cotton 
is wrung; it is then preffed, and put to foak in running wa- 
ter, after being inclofed in a bag of thin cloth. 
The workmen then procced to the dyeing.—To compofe 
. the colours they put in a kettle five occas of water and thirty- 
five occas of a root which the Grecks call ali-zari, or paint- 
_ ing colour, and which in Europe is known under the name 
of madder, The madder, after being pulverifed, is moiftened 
‘with one occa of ox or fheep’s blood. The blood ftrengthens 
the colour, and the dofe is increafed or leffened according to 
the fhade of colour required, An equal heat is maintained 
below the kettle, but not too violent; and when the liquor 
ferments, and begins to grow warm, the fkains are then gra- 
dually immerfed before the liquor becomes too hot. They 
are then tied with packthread to imall rods, placed croflwife 
above the kettle for that purpofe, and when the liquor boils 
well, and in an uniform manner, the rods from which the 
fkains were fufpended are removed, and the cotton is fuffered 
to fall into the kettle, where it muft remain till two-thirds 
of the water is evaporated. When one-third only of the 
liquor remains, the cotton is taken out and wafhed in pure 
) water. 
The dye is afterwards brought to perfection by means of a 
‘bath alcalifed with foda. This manipulation is the moft dif- 
"ficult and the moft delicate of the whole, becaufe it is that 
' which gives the colour its tone. The cotton is thrown into 
this mew bath, and made to boil over a fteady fire ull the 
colour affumes the required tint. The whole art confifts in 
catching the proper degree: a careful workman, therefore, 
mutt watch with the utmoft attention for the moment when 
it is neceflary to take out the cotton, and he will rather burn 
“his hand than mifs that opportunity. 
It appears that this bath, which the Greeks think of fo 
“Much importance, might be fupplied by a ley of foapz and 
it is probable that faponaceous water would give the colour 
“more brightnefs and purity. 
When 


325 Extrad of a Memoir on the 


When the colour is too weak, the Levantines know how 
to ftrenethen it by increafing the dofe of the colouring fub- 
_flances; and when they withhite give it brightnefs and fplen- 
dour, they employ different roots of the country, and, in par-, 
ticular, one named /afazri, {fpecimens of which I have fent to _ 
France. 

’ The ali-zari, which is the principal colouring matter em- 
ployed in the Greek dye-houfes, is collected in Natohia, 
and is brought to Greece from Smyrna: fome of it comes 
alfo from Cyprus and Mefopotamia. The fuperiority of this a 
Levantine plant to the European madder is acknowledged by — 
all thofe acquainted with the art of dyeing and may arife 
from two caufes; the manner in which it is cultivated, and 4 
the method employed for its deficcation. ‘ 

As the ali-zari appears to be of a weaker conftitution than 
the common madder+ as its branches are more delicate, its 
Jeaves fmoother and tenderer, and its ftem more fragile, it 
is fupported by fticks, as peafe are among us. <A well nou- 
rifhed ftem acquires in this manner more confiftence, and 
fends forth more roots. It is to be obferved, that it is the 
woody part of the roots which affords the greateft quantity of 
colouring particles. The ali-zari is not colleéted till the — 
fifth or fixth year, that is to fay, when it has aequired its 7 
full ftrength ; while in France and Zealand, where land is of 
more value than in the Levant, the inhabitants with to reap 7 
too foon, and collect the madder before it comes to complete 


maturity. 
The method employed in the deficcation contributes alfo 3 
to improve the quality of the ali-zari. The Levantines dry © 
it in the open air; and this operation is eafy na country 
where great drynefs prevails in he atmofphere, while, in our # 
damp Anoatees we are obliged to dry the madder by foves. 
Hence it happens that the {moke, which mixes itfelf with } 
the cold air, and penctrates the rocts, impreenates them with he 
fuliginous particles, which alter the colouring fabftance; an 
accident which does not take place when the madder is dried’ 
‘without the affiftance of fire. It is, however, poffible, that ~ 
the ali-zari and’ madder may never produce the fame tone of — 
colour, notwithftanding all the care that may be employed 
eas. 6 in 


Grecian Metbod of dyeing Cotton Yarn Red. 329 


in the culture and drying of the latter; becaufe there may 
be as much difference between thefe two plants, fo like to 
each other, as between the goats of France and thofe of 
Angora. 

It is probable, alfo, that the fuperiority of the ali-zari over 
miadder may arife only from its ftem being tenderer, and by 
its confequently having a greater difpatition to transform it- 
felf into fucculent roots. In that cafe, feveral of our indige- 
nous plants of the family of the rudie might be fubftituted 


“in its place with advantaze; fuch as the gallium luteum and 


gallium fiore albo, found in abundance on the hills of Poitou, 
and the madder, which grows on both fides of the Alps, and 
which has been diftinguifhed by the name of rubia levis 
-Tourinenfium. All thefe ‘plants give a red as beautiful and 
as pure as the belt madder; but I do not know whether the 
quantity of their colouring matter is equal to their beautiful 
quality. 

The chief manufactories for dyeing fpun cotton red, efta- 
blifhed in Greece, are in Theflaly. There are fome at Baba, 
Rapfani, Tournavos, Lariffa, Pharfalia, and in all the vil- 
lages fituated on the fides of Offa and Pelion. Thefe two 


- mountains may be confidered as the alembics that diftil the 


eternal vapours with which Olympus is crowned, and which 


_diftribute them throughout the beautiful valleys fituated 


around them. Of thefe valleys, that of Tempe has at all 
times been diftinguifhed by the beauty of its fhady groves 


‘and of its ftreams. Thefe fireams, on account of their lim- 


pidnefs, aré very proper for dyeing, and fupply water to a 
great number of manufactories, the moft celebrated of which 
are thofe of Ambelakia. 

Ambelakia, on account of the aétivity which prevails in it, 


. has a greater refemblance to a town of Holland than a vil- 


Jage of Turkey. This village, by its induftry, communicates 


_ life and aétivity to all the neighbouring country, and gives 


birth to an immenfe trade, which conneéts Germany with 


| ; Greece in a thoufand ways. Its population, which has been 
tripled within thefe fifteen years, amounts at prefent to 4900, 


_,and all thefe people exift by dyeing. None of thofe vices or 
_ cares produced by idlenefs are known. here. The hearts of 


VOL. V: Uu ; the 


f a7 —T 7 
aN 
, ~ 
j 


7 


330 An Account of the 
the mhabitants are pure, and their countenances unclouded. 
Servitude, which degrades the countries watered by the Pe- 
neus, has not yet afcendcd to thefe hills: no Turk can refide 
or live among thefe people ; and they govern themfelyes, like 
their anceftors, by their protoyeros and helt own magiftrates. 
_ Twice have the favage muffulmans of Lariffa, envious of their 
eafe and happinefs, attempted to fcale their mountains in 
order to plunder their houfes; and twice have they been re- 
pulfed by hands which fuddenly quitted the fhuttle to affume 
the mufket. 

All hands, and even thofe of the children, are employed 
in the dye-houfes of Ambelakia; and while the men dye the 
cotton, the women are {pinning and preparing it. The ufe 
of wheels is not known in this part of Greece ; all the cotton 
is fpun on a diftaff: the thread, indeed, is certainly not fo 
round or equal, but it is fofter, more filky, and more tena- 
cious; it is lefs apt to break, and lafts longer ; it is alfo more 
eafily whitened, and more proper for being dyed. It is a 
pleafing {pectacle to fee the women of Ambelakia, each fpin- 
ning from a diftaff, and fitting converfing together on the 
threthold of their doors; but as foon as a ftranger appears, 
they inflantly retire and conceal themfelves in their houfes, 
manifefting, like Galatea, in their precipitate retreat, a defire 
of flying and of thewing themfelves :— 

, Et fugit ad falices, et fe cupie ante vide:i. 

The eye can only have a curfory view of the fhape of fome 
of thefe women}; but it till obferves, with furprife, thofe 
flender and graceful forms of the ancient Grecian females, 
which ferved as models to the mof beautiful ftatues in the 
world. 


V. An Account of the Wild Horfes in Spanifh America. 
By D. Ferrx Azara*, 


I HESE animals were originally carried from Spain by 
the firft ¢onquerors, and are of the Andalufian breed. They 
* From a work, not yet publithed, on the natural hiftory of Paraguay, 


by Don Felix Azara, brother of the late Spanith ambaffador at Paris. 
This extract is tranflared from the Decade Philofophique, No. 9, year 8. 


chiefly 


Wild Horfes in Spanifh America. 331 
chiefly frequent the fouthern part of the river de la Plata, 
as far as Rio Negro, the country of the Patagonians, &c. 
The wild horfes of all thefe countries live in numerous herds, 
fome of which, it is faid, confift of ten thoufand. As foon 
as they perceive domeftic horfes in the fields, they run to- 
wards them on a full gallop, pafs through the middle of 
them, or near them, carefs them, and invite them with a 
kind of grave and prolonged neighing, The domseltic horfes 
are foon feduced, unite themfelves to the independent herd, 
and depart along with them. It happens not unfrequently 
that travellers are ftopped on the road by the effect of this 
defertion. ‘To prevent it, they halt as foon as they perceive 
thefe wanderers, watch their own horfes, and endeavour to 
frighten away the others. In fuch cafés the wild horfes fol- 
low a certain kind of tactics; fome are detached before, and 
the reft advance in a clofe column, which nothing can in- 
terrupt. If they are fo alarmed as to be obliged to retire, 
they change their direction, but without fuffering themfelves 
to be difperfed: fometimes they make a great number of 
turns around thofe which they with to feduce, in order to 
frighten them; at other times they retire after making one 
turn. Thefe manceuvres are not employed during the night, 
for the wild horfes then make no attempts. The author is 
ignorant whether any thing of the fame kind takes place 
between one herd of wild horfes and another for the purpofe 
of recruiting their number. He afferts. that Buffor is mif- 
taken in faying that thefe wild horfes have more ftrength 
and fleetnefs than the domeftic horfes of the country, and 
that they do not differ from the latter either in height or 
fhape: but he indeed obferves, that no comparifon cam be 
made between the independent and domeftic ftate of thefe 
animals, as in that country both ftates are almoft fimilar. 

Thofe who poflefs effanczas, or paftures for keeping do- 
meftic horfes, place in them a certain number of mares, 
which are never broke or mounted. They remain during 
their whole lives in a ftate of perfect liberty; and for every 
thirty or forty mares there is a ftallioh, which enjoys the 
fame independence. They are counted once or twice a week, 
in order that they may not ftray from the habitation. But 

Uuz- too 


332 An Account of the 


too little care is employed in the choice of the ftallions; and 
this, in all probability, 1s one of the principal caufes why 
thefe horfes, though left at full liberty, are neither fo beau- 
tiful nor fo good as thofe of Andalufia, from which they are 
defcended. The induftry of man improves the breed of thofe 
animals which he appropriates to his own ule, and, by 
bringing their fhape and organs to perfeétion, indemnifies 
them for that liberty of which he deprives them. Each 
ftallion takes poffeffion of a fmall troop of mares, which he 
keeps collected by preffing them with his cheft, and by biting 
them if they do not obey with fufficient docility: the mares, 
on the other hand, remain attached to their fultans. If two 
ftallions fight, the mares do not abandon the conquered for 
the conqueror, unlefs ‘the former has fhewn among them ars 
deficiency of vigour. 

The fillies remain with their mothers. When it is time 
to break the colts they are cut, for no perfon mounts a horfe 
until that operation has been performed. After caftration, 
a halter is put upon the animal intended to be broke; he is 
tied to a ftake; a faddle is placed upon his back, and well 
girded, but without crupper or breaft-leather, and a thong 
is tied round his under-lip, to which is faftened, on each 
fide, a rein, in order to govern him, The horfeman then 
mounts with large fpurs, and rides out into the fields. At 
firft the young horfe capers and jumps until he is quite fa- 
tigued ;' afier which he is brought back to the ftake. This 
exercife is repeated feveral times in the courfe of the fame 
day, and is renewed after the interval of feveral days until 
the courfer capers no more. He is then employed as a broke 
horfe, but with a halter only; a bridle is not put upon him 
till a year after, at which time he quits the name of rodo- — 
mont to affume that of horfe. 

As foon as the horfes are cut, they are feparated from iis 
mares, and put among tle animals of the Baik fpecies ufed 
for fervice, which receive no other fhelter or food than what 
they find im the fields. They are accuftomed to live in one 
canton, which they never quit. Each unites himfelf toa 
companion, and with fuch intimacy that inftances have 
. been known of fome of ars after ranning away, having 
‘ returned 


Wild Horfes in Spanifb America. 333 
returned more than fixty leagues to rejoin their old friend. 
Thefe friends know each other by their neighing, their fell, 
and the noife of their pace. 

When the proprietors are defirous to prevent a numerous 
troop of domeftic horfes from feparating, they place among 
them a young mare with a fmall bell, and which is then 
called the godmother. They all follow her, and they all 
know and feek for each other as members of the fame fo- 
ciety. The fame effet may be produced by attaching the 
dell to one of the horfes of the troop. 

When the inhabitants have need of horfes, a man on 
horfeback, bearing a lance, proceeds towards a troop of 
thefe animals, and drives them into an inclofure formed of 
pallifades. A horfeman then enters it, and, when he is 
within reach, entangles the horfe which he wifhes to 
catch with a kind of rope; for, though thefe horfes are fit 
to be mounted, and faid to be docile, they will not fuffer 
themfelves to be touched with the hand. 

From what has been faid, it may be readily feen that there 
is really very little difference between the habits of thefe wild 
horfes and of thofe which live in a ftate of domefticity. It 
needs excite no wonder, therefore, that there fhould be very 
little in regard to their form, fize, and qualities. 

When the inhabitants wifh to convert fome of thefe wild 
horfes into domeftic ones, people mounted on horfeback - 
proceed towards a troop of the former; and when they ap- 
proach them they throw fome of the ropes already mentioned 


around their legs, fo that, being prevented from running, 


they havetime to fecure them. They are then tied toa ftake, 
or a tree, not by the four legs, as fome have faid, but with 
a fimple halter made of leather. They are left two or three 
days without food or drink, are afterwards cut, and are then 
broke in the fame manner as the domeftic horfes. The horfe 
behaves then as if he had never been wild; but it is not true’ 
that they lofe all defire of recovering their hberty. They 
readily unite with a troop of wild horfes; and how can it be 
otherwife, fince thofe even which have been reared in a ftate 
of domefticity have no repugnance to join them ? 
The proprietors of the ¢/fancias, or paftures deftined for 
5 thofe 


334 On the Wild Horfes of Spanifh America. 


thofe horfes which have been tamed, endeavour not only to 
frighten away the wild horfes, but even to exterminate them. 
With that view they beat the woods in queft.of them, drive 
them, if poffible, into ravines, and kill them by means of 
lances. 

The Pampas eat their flefh, and particularly that of the 
fillies, colts, and mares; but they fometimes kill a very fat 
fiallion to make a fire with his greafe and bones, as in the 
country of Pampa’ wood is extremely fearce. 

The Spanifh author often contradiéts Buffon, not only in 
regard to local obfervations, which is not aftonifhing, but 
alfo in regard to general ideas, fuch as the influence of cli- 
mate, &c. D. Felix Azara refutes the affertion of the French 
naturalift, who afcribes more ftrength and fleetnefs to the 
wild than to the domettic horfes of thefe countries. He even 
afferts, that’ he has not been correct in faying that each wan- 
dering troop fubmit, by common confent, to a chief, which 
ferves as a guide; which regulates. and directs their move- 
ments; forms them in the order of battle, by files, compa- 
nies, {quadrons, &c. The truth, according to the author, is, 
that each ftallion appropriates to himfelf as many mares as . 
he can, which he takes care of, and keeps collected; that 
he combats any other ftallion which attempts to deprive him 
of them; and that each wandering troop confifts, therefore, 
of a number of fmall diftin& bodies, which fometimes unite 
into one. : 

In the great number of wild troops which the author faw, 
he never obferved any other prevailing colours than bay, 
dark brown, and jet black. If it fometimes happens that a 
pied or dirty grey coloured individual is feen, or one of any 
other colour, it may with certainty be concluded that it is a 
domeftic horfe which has deferted.. According to the author, 
there are ninety bay for one dark brown horfe; and black 
horfes are fo uncommon, that one of them is fcarcely feen in 
two thoufand. He thence infers, that thefe three colours, 
bay, dark brown, and jet black, are a primitive mark, which 
diftinguifhes, at leaft im part, the horfes which recover their 
liberty; that the firft horfe and mare which exifted had one 
of thefe three colours, and moft probably the bay, fince it 

appears 


An Account of the Pearl Fifbery at Ceylon. 335 


appears that, among the wild horfes, the black is becoming 
extin@t, and that this will be the cafe alfo with the browns 
that, taking the colour as an index, we might fay, that the 
beft breed of horfes is the bay, then the brown, and next 
the black ;: all the other colours being inferior, as they are 
the refult of more diftant degradations from the primitive 
horfe, which muft have been the moft perfect. Experience 
feems, in fome meafure, to confirm thefe conjeGures; for, 
except in a few cafes, which are of little confequence, the 
bays are the moft efteemed, and the browns hold the next 
rank. He obferves, that in France a prejudice is entertained 
againft the laft-mentioned colour, which he thinks unrea- 
fonable, and which in his opinion feems to fhew that the 
French, in this refpect, have not fo much difcernment as the 
Spaniards. Thefe obfervations, and the inferences which the 
author draws from them, feem to weaken the confidence 
which might be placed in what has been faid by Buffon, on 
the authority of Herodotus, Leo Africanus, and Marco Polo, 
of wild white horfes faid to have exifted in Arabia and Nu- 
midia. We know how fufpicious the teftimony of the an- 
cients is in regard to natural hiftory, and that the authonty 
of Buffon himlele has little weight when he gives toftimasnies 
inftead of obferved facts. 


VI. An Account of the Pearl Fifbery in the Gulpbiof Manar, 
in March and April 1797. By Henry J. Le Becx, 
E/q.* 


Fro M -the accounts of the former pearl fifheries at Cey- 
lon, it will be found, that none have ever been fo produétive 
as this year’s. It was generally fuppofed that the renter 
would be infallibly ruined, as the fum he paid for the pre- 
fent fifhery was thought exorbitant when compared with 
‘what had been formerly given: but this conjecture in the 
event appeared ill- founded, as it proved extremely profitable 
-and lucrative. 

The farmer this time was a Tamul merchant, who, for 


* From the Afiatic Refearches, Vol. V. 
the 


336 An Azcount of the Peart Fifbery at Ceylom 

the privilege of fifhing with more than the ufual number of 
donies or boats, paid between two and three hundred thou 
fand Porto-novo pagodas ; a fum nearly double the ufual rent: 

Thefe boats he farmed out again to individuals in the beft 
manner he could, but for want of a fufficient number of 
divers fome of them could not be employed. 

The fifhing, which commonly began about the middle of 
February, if wind and weather allowed, was this year, for 
various reafons, delayed till the end of the month; yet, fo 
favourable was the weather, that the renter was able to take. 
advantage of the permiffion granted by the agreement, to fith 
a little longer than the ufual period of thirty days. 

The fifhery cannot well be continued after the fetting-in 
of the fouthern monfoon, which ufually happens about the 
r5th of April, as, after that time, the boats would not be 
able to reach the pearl banks, and the water being then fo 
troubled by heavy feas, diving would be impraticable; in 
addition to which, the fea-weed, a {pecies of fucus, driven 
in. by the foutherly wind, and which fpreads to a confidera- 
ble diftance from the fhore, would be an impediment. 

Many of the divers, being Roman Catholics, leave the 
fifhery on Sundays to attend divine fervice in their church at 
Aripoo; but if either a Mahomedan or Hindoo feftival hap« 
pens during the fifhing days, or if it is interrupted by ftormy 
weather, or any Aine accident, this loft time 1s made up by 
obliging the Catholics to work on Sundays. 

The fie of fharks, as we. {hall feé hereafter, is-alfo ans. 
other caufe of interruption. Thefe, amongft fome others, 
are the reafons that, out of two months, (from February till 3 
~ April,) feldom more than thirty days can be employed in- the 

fifhery. 

As this time would be infufficient to fifly all the banks, 
(each of which has its appropriate name, both in Dutch and 
Tamul,) it is carried on for three or four fucceilive years, 

-and a new contract: annually made, till the whole banks have 
been fifhed; after which they are left to recover. 

The length of time required for this purpofe, or from one 
general fifhing te another, has not yet been exactly deter-_ 
mined ; it was therefore a practice to depute fome perfons to 

; ib q 4 


An Account of the Pearl Fifbery at Ceylon. 337 


_yifit the banks annually, and to give their opinion, whether 


a fifhery might be underiaken with any degree of fuccefs*? 
From yarious accounts, which I have collected from good 
authority, and the experience of thofe who affifted at fuch 
examinations, I conjecture, that every feven years fuch a 
general fifhery could be attempted with advantage, as this 
interval feems fufficient for the pearl fhells to attain their 
growth: I am alfo confirmed in this opinion by a report, — 
made by a Dutch governor at Jafuas, of all the fitheries that 
have been undertaken at Ceylon fince whit 3 a tranflation of 
which is to be found in Wolfe’s Travels into Ceylon. But 
the ruinous condition “in which the divers leave the pearl 
banks at each fifhery, by attending only to the profit of in- 
dividuals, and not to that of the public, is one great caufe 
that it requires twice the above-mentioned fpace of time, and 
fometimes longer, for rendering the fifhing productive. They 
do not pay the leaft attention to fpare the young and imma- 
ture fhells that contain no pearl; heaps of them are feen 
thrown out of the boats as ufelefs on the beach between 
Manar f¢ and Aripoo: if thefe had been fuffered to remain 
in their native beds, they would, no doubt, have produced 
many fine pearls. It might therefore be advifable to oblige 
the boat-people to throw them into the fea again before the 
boats leave the bank. If this circumfpedticn, in fparing the 
fall pearl {hells to perpetuate the breed, was always ob- 
ferved, fucceeding fifheries might be expe€ted fooner, and 
with ftill greater fuccefs: but the negle& of this fimple pre- 
caution will, I fear, be attended with fimilar fatal confe- 
quences here, as have*already happened to the pearl banks 


~ on the coalt of Perfia, South America, and Sweden, where 
> 2 


the fifherics are by no means fo profitable at prefent as they 
were formerly. 

Another caufe of the deftruction of numbers of both old 
and young pearl fhells is the anchoring of fo many boats 


* A gentleman, who affifted at one of the laft vifits, being an engincer, 
drew a chart of the banks, by which their fituation and fize are now better 
known than formerly. 

+ Manara, properly Manar, is a Tamul word, and sacle a fandy 
fiver, from the fhallownefs of the fea at that place. 


‘Vox.. V. Met on 


338 An Account of the Pearl Fifbery at Ceylon. 


on the banks; almoft all of them ufed differently formed, 
clumfy, heavy, wooden anchors, large ftones, &c. &e. If 
this evil cannot be entirely prevented, it might, at leaft, be 
greatly leflened, by obliging them all to ufe anchors of a 
particular fort, and lefs deftructive. 

This feafon the Seewel Bank only was fifhed, which lies 
above twenty miles to the weftward of Aripoo, oppofite to 
the frefh water rivers of Moofalee, Mcdragam, and Pompa- 
ripoo. It has been obferved, that the pearls on the north- 
weit part of this bank, which confifts of rock, are of a clearer 
water than thofe found on the fouth-eaft, neareft the fhore, 
growing on corals and fand, 

Condatchey is fituated in a bay, forming nearly a half 
moon, and is a wafte, fandy diftriét, with ae miferable 
huts built on it. - The water is bad and brackifh, and the 
foil produces only a few, widely feattered, ftunted trees and 
bufhes. Thofe perfons who remain here during the fifhery 
are obliged to get their water for drinking from Aripoo, a 
village with a {mall old fort, lying about four miles to the 
fouthward. Tigers, porcupines, wild hogs, pangolines, or 
the Ceylon armadillos, are, amongft other quadrupeds, here 
common. Of amphibia, there are tortoifes, efpecially. the. 
teftudo geometrica, and various kinds of fnakes. A concho- 
logift meets here with a large field for his enquiries. The 
prefents which I made to the people employed in the fifhery, 
to encourage them to colleét. all forts of fhells which the 
divers bring on fhore, produced but little effe&t; as they were 
too much taken up in fearching after the mother-of-pearl 
fnells to pay attention to any other ,objeét. However, my 
endeavours were not entirely ufelefs; I will fpecify here a 
few of the number I collected during my ftay: different — 
kinds of peéfines*, palium porphyreum, folen radiatus Tt, © 
Venus caftrenfis Linn. } aftrea hyotis§, ofr. Forfkohi, ofr. 
Malleus ||, mytilus birundo Linn. §, /pondilus crocius, pholgs 4 


* Scallops. + Radiated razor-fhell. 

+ Alpha cockle. § Double cock’s-comb. : 

lI viguiner oyfter; thefe were pretty large, but many broken, and fome 

-covered by a calcareous cruft. It is yery probable that arnong thofe there 
may be fome precious qwh/fe ones. @ Swallow i 


An Account of the Pearl Fifbery at Ceylon. 339 
pufillus Linn.*, ‘mitra epifcopalis Linn., lepas firiata 
Pennanti, (vide Zool. Brit.) patella tricarinata Linn., 
bulla perfecia maculatat, barpa nobilis, porcellana falita 
Rumph.t, firombus fcorpio, and other of inferior kinds, 
Amongft the zoophytes, many valuable fpecies of /pongie, 
coralline, fatularie, &c. a great variety of fea-ftars, and 
other marine productions, that cannot be preferved in fpirits, 
but fhould be defcribed on the fpot. Thefe, as weil as the 
defcription of the different animals inhabiting the fhells, are 
the more worthy of our attention, and deferve farther invef- 
tigation, as we are yet very deficient in this branch of na- 
tural hiftory. 

During the fifhing feafon, the defert, barren place Con- 
datchey offers to our view a fcene equally novel and afto- 
nifhing. A heterogeneous mixture of thoufands of people, of 
different colours, countries, cafts, and occupations; the num- 
ber of tents and huts ereéted on the fea-fhore, with their 
fhops or bazars before each of them; and the many boats 
returning on {hore in the afternoon, generally richly laden ; 
all together form a fpeétacle entirely new to an European 
eye. Each owner runs to his refpective boat as foon as it 
reaches the fhore, in hopes of finding it fraught with immenfe 
treafure, which is often much greater in imagination than 
in the fhell; and though he is difappointed one day, he relies 
with greater certainty on the next, looking forward to the 
fortune promifed him by his ftars, as he thinks it impoffible 
for the aftrological predictions of his Brahmen to err. 

‘To prevent riot and diforder, an officer with a:party of 
Malays is ftationed here. They occupy a large fquare, where 
they have a field-piece, and a flag-ftaff for fignals. 

Here and there you meet with brokers, jewellers, and mer- 
chants, of all defcriptions; alfo futtlers, offering provifions 
and other articles to gratify the fenfual appetite and luxury, 
But by far the greater number are occupied with the pearls. 
Some are bufily employed in afforting them ; for which pur- 
pofe they make ufe of {mall brafs plates perforated with holes 
of different fizes; others are weighing, and offering them to 


* The wood-piercer. + Diving fnail, (Grew, Muf.) 
yin | + Salt-coury, KI. 


Xx2 the 


- 


340 An Account of the Pearl Fifhery at Ceylon. . 


the purchafer; while others are drilling or boring them} 


which they perform for a trifle. 

The inftrument thefe people carry about with them for 
this purpofe is of a very fimple conftruétion, but requires 
much fkill and exercife to ufe it; it is made in the following 
manner: The principal part confifts of a piece of foft wood, 
of an obtufe, inverted, conical fhape, about fix inches high 
and four in diameter in its plain furface; this is fupported 
by three wooden feet, each of which is more than @ foot in 
length. Upon the upper flat part of this machine are holes 
or pits for the larger pearls, and the fmaller ones are beat 
in with a wooden hammer. On the right fide of this ftool, 
half a cocoa-nut fhell is fattened, which is filled with water. 
The drilling inftruments are iron fpindles, of various fizes, 
adapted to the different dimensions of the pearls, which are 
turned round in a wooden head by a bow. The pearls being 


placed on the flat furface of the inverted cone, as already 


mentioned, the operator, fitting on a mat, prefles on the 
wooden head of his inftrament with the left hand, while, 
with his right, he moves the bow which turns round the 
moveable part of the drill; at the fame time he moiftens the 
pearl, occationally dipping the little finger of the fame hand 
into the water of the cocoa-nut fhell with a dexterity that 
can only be attained by conftant practice. 

Among the crowd are found vagabonds of every deferip- 
tien, fuch as Pendarams, Andee or Hindu monks, fakirs, 
beggars, and the like, who are impertinently troublefome. 
Two of thefe arretes particularly attraced the attention of 
the mov, though their fuperftitious penance muft have dif- 
guited a man of the leaft reflection: one had a gridiron, of 
one foot and a half long and the fame in breadth, faftened 
round his neck, with which he always walked about, nor 
did he take it off either when eating or fleeping; the other 
had fafiened round that member which decency forbids me 
to mention, a brafs ring, and fixed to it was a chain, of @ 
fathom in length, trailing on the ground; the links of this 
chain were as thick as a man’s finger, and the whole was 
exhibited in a moft. feandalous manner. ‘ 

The peflilential fmell occafioned by the numbers of putre- 


7 fying © 


An Account of the Pearl Fifhery at Ceylon. 341 


fying pearl fithes, renders the atmofphere of Condatchey fo 
infufferably offenfive when the fouth-weft wind blows, that it 
fentibly atieéts the olfactory nerves of any one unaccuftomed 
to fueh cadaverous {mells. This putrefaction generates im- 
menfe numbers of worms, flies, mufkitoes, and other vermin, 
all together forming a fcene ftrongly difpleafing to the fenfes. 

Thoie who are not provided with a fufficient ftock of mo- 
ney fufier great hardfhips, as not only all kinds of provifions 
are very dear, but even every drop of good water mutt be 
paid for. Thofe who drink the brackifh water of this place 
are often. attacked by ficknefs. It may eafily be conceived 
what an effect the extreme heat of the day, the cold of the 
night, the heavy dews, and the-putrid fmell, muft have on 
weak conftitutions. It is therefore no wonder, that of thofe 
who fall fick many die, and many more return home with 
fevers, fluxes, or other equally fatal diforders. 

The many difappointments ufually experienced by the 
lower clafles of men in particular, make them often repent 
of their coming here. They are often ruined, as they rifk 
all they are worth to purchafe pearl fhells: however, there 
are many inftances of their making a fortune beyond all ex- 
pectation. A particular circumftance of this kind fell within 
my own obferyation: a day labourer bought three oyfters * 
for a copper fanam, (about the value of two-pence,) and was 
fo fortunate as to find one of the largeft pearls which the 
fifhery produced this feafon. 

The donies appointed for the fifhery are not all procured 
at Ceylon; many came from the coafts of Coromandel and 
Malabar, each of which has its diftinguifhing number. 
About ten o’clock at night a gun ts fired as a fignal, when 
they fail from Condatchey sith an eafterly or land wind, 
under the direction of a pilot. If the wind continues fair, 
they reach the bank before day, and begin diving at fun-rife, 
which they continue till the weft or fea-breeze fets in, with 
which they return. The moment they appear in fight, the 


* The Eaft India pearl fhe!l is well known to be the matrix perlarum 
(mother-of-pearl) of Rumphius, or the Myzi/us margaritiferus of Linneus, 
confequently, the general term pearl-oyfter mutt be erroneous: however, 
a: it has aang been in common ule, i hope to be exculed for continuing it. 

colours 


34% An Account of the Pearl Fifhery at Ceylon. , 


eolours are hoifted at the flag-ftaff, and in the afternoon they 
come to an anchor; fo that the owners of the boats are’ 
thereby enabled to get their cargoes out before night, which 
niay amount to 30,000 oytters, if the divers — been active 
and fuccefsful. 

Each boat carries twenty-one men and five heavy diving- 
fiorics, for the ufe of ten divers, who are called in Tamul 
kaoly kérer; the reft of the crew: confifts of a tandel, or head 
boatman, and ten rowers, who aflift in lifting up the divers 
and their fhells. 

The diving-{tone is a piece of coarfe granite, a foot long, 
fix inches thick, and of a pyramidical fhape, rounded at the 
top and bottom. A large hair rope is put through a hole in 
‘the top. Some of the dive rs ufe another kind of ftone, thaped 
like a half moon, to bind round their belly, fo that their feet 
may be free. At prefent thefe are articles of trade at Con- 
datchey. The moft common, or pyramidical ftone, generally 
weighs about thirty pounds. If a boat has more than five 
of them, the crew are either corporally punifhed or fined. 

The diving, both at Ceylon and at Tutucorin, is not attend- 
ed with fo many difficulties as authors imagine. The divers, 
confifting of different cafts and -religions, “fthtoniga chiefly of 
Pavrawer * and Muflulmans,) neither make their ‘bodies 
fmooth with oil, nor do they ftop their ears, mouths, or 
nofes with any thing, to prevent the entrance of falt water. 
They are ignorant of the utility of diving-bells, bladders, and 
double fiedible pipes.. According to the injunctions of the 
fhark conjurer they ufe no food while at work, nor till they 

return on fhore and have bathed themfelves in frefh water. 
Thefe Indians, accuftomed to dive from their earlieft infancy, 
fearlefsly defeend to the bottom, in a depth of from five to 
ten fathoms, in fearch of treafures.. By two cords a diving- 
fione and a net are connected with the boat. The diver, 
putting the toes of his right foot on the hair rope of the 
diving-ftone, and thofe of his left on the net, feizes the two 
cords with one hand, and, fhutting his noftrils with the other, 
plunges into the water. On reaching the bottom, he hangs 
the net round his neck, and collects into it the pearl fhells 


* Fifhermen of the Catholic religion. aaa 
as 


An Account of the Pearl Fifbery at Ceylon. 343 


as faft as poflible during the time he finds himfelf able to 
remain under water, which ufually is about two minutes. 
He then refumes his former pofture, and making afignal, by 
pulling the cords, he is immediately lifted into the boat. On 
emerging from the fea, he difcharges a quantity of water from 
his mouth and nofe, and thofe who have not been long enured 
to diving frequently difcharge fome blood; but this does not 
prevent them from diving again in their turn. When the 
firft five divers come up, and are refpiring, the other five are 
going down with the fame ftones. Each brings up about 
one hundred oyfters in his net, and, if not interrupted by any 
accident, may make fifty trips in a forenoon. They and the 
boat’s crew get generally from the owner, inftead of money, 
a fourth of the quantity which they bring on fhore; but fome 
are paid in cafh, according to agreement. 

The mott fkilful divers come from Coilith, on the coaft of 
Malabar ; fome of them are fo much exercifed in the art, as to 
be able to perform it without the affiftance of the ufual weight, 
and for a handfome reward will remain under water for the 
fpace of feven minutes: this I faw performed by a Caftry 
boy, belonging to a citizen at Karical, who had often fre- 
quented the fitheries of thefe banks. Though Dr. Halley 
deems this impoffible, daily experience convinces us, that, 
by long practice, any man may bring himfelf to remain under 
water above a couple of minutes. How much the inhabit- 
ants of the South Sea Iflands diftinguith themfelves in diving 
we learn from feveral, accounts; and who will aot be fur- 
prifed at the wonderful Sicilian diver Nicholas, furiiamed the 
Fith *? 

_ Every one of the divers, and even the moft. expert, enter- 
tain a great dread of the fharks, and will not, on any ac- 
count, defcend until the conjurer has performed his cere- 
monies. This prejudice is fo deeply rooted in their minds, 
that the government was obliged to keep two fuch conjurers 


* According to Kircher, he fell a vitim amongt the Polypes in the 
‘guiph of Chirybdis, on his plunging, for the fecond time, in its dax- 
gerous whirlpool, -both to fatisfy the curiofity of his king, Frederic, and 
his inclination for wealth. I will not pretend to determine how far this 
account has been exaggerated, 

always 


344 _ An Account of the Pearl Fifbery at Ceylon, 


always in their pay, to remove the fears of their divers. 
Thirteen of thefe men were now at the fithery from Ceylon 
and the coaft, to profit by the fuperftitious folly of thefe 
deluded people. They are called in Tamul Pillal Kadtir, 
which fignifies one who binds the fharks, and prevents them 
from doing mifchief. 

The manner of enchanting confifts in a number of prayers 
learned by heart, that nobody, probably not even the con- 
jurer himfelf, underftands, which he, ftanding on the fhore, 
continues muttering and grumbling from fun-rife until the 
boats return: during this period they are obliged to ab{tain 
from fvod and fleep, otherwile their prayers would have no 
avail; they are, however, allowed to drink, which privilege 
they indulge in a high degree, and are frequently fo giddy 
as to be rendered very untit for devotion. Some of the con- 
jurers acccmpany the divers in their boats; which pleafes 
them very much, as they have their protectors near at hand. 
Neverthelefs, I was told, that in one of the preceding fifheries _ 
a diver loft his leg by a fhark; and when the head conjurer 
was called to an account for the accident, he replied, that an 
old witch had juft come from the coaft, who, from envy arid 
malice, had caufed this difafter by a counter-conjuration, 
which made fruitlefs his fkill, and of which he was informed 
too late: but he afterwards fhewed his fuperiority by en- 
chanting the poor fharks fo effeCtually, that, though they ap- 
peared in the midft of the divers, they were unable to open 
their mouths. During my ftay at Condatchey, no accident . 
of this kind happened. If a fhark is feen, the divers imme- 
diately make a figna!, which on perceiving, all the boats re- 
turn infiantly. A diver who trod upon a hammer-oytter, 
and was fomewhat wounded, thought he was bit by a thark, 
confequently made the utual fignal; which caufed many boats 

.to return; for which miftake he was afterwards punifhed. 

The owners of the boats * fometimes {ell their oyfters, and 
at other times open them on their own account. -In the latter 
eafe, fome put them on mats in a {quare, furrounded witha _ 


* Thefe are the individuals which farm one or more boats from the 
renter; and though they are in poffeflion of them-only during the ee 
they are conimonly called the owners of the boats. ' 
j fue ; 


An Account of the Pearl Fifbery at Ceylon. 345 


fence; others dig holes of almoft a foot deep, and throw 
them in till the animal dies; after which they open the 
fhells, and take out the pearls with more eafe. Even thefe 
{quares and holes are fold by auétion after the fifhery is 
finifhed, as pearls often remain there mixed with the fand. 

In fpite of every care, tricks in picking out the pearls from 
the oyfters can hardly be prevented. In this the natives are 
extremely dexterous. The following is one mode they put 
“in practice to effeét their purpofe: when a boat-owner em- 
ploys a number of hired people to colle& pearls, he places 
ever them an infpector of his own, in whom he can confide 5 
thefe hirelings previoufly agree that one of them fhall play 
the part of a thief, and bear the punifhment, to give his 
comrades an opportunity of pilfering. If one of the gang 
happens to meet with a large pearl, he makes a fign to his 
accomplice, who inftantly conveys away one of fmall value, 
purpofely, in fuch a manner as to attra& notice. On this 
the infpeCtor and the reft of the men take the pearl from 
him: he is then punifhed, and turned out of their company. 
In the mean time, while he is making a dreadful uproar, the 
real thief fecures the valuable pearl, and afterwards the booty 
is fhared with him who fuffered for them all. Befides tricks 
like thefe, the boat-owners and purchafers often lofe many 
of the beft pearls while the dony is returning from the bank ; 
for, as long as the animal is alive, and untouched, the fhells 
are frequently open near an inch; and if any of them con- 
_ tain a large pearl, it is eafily difcovered, and taken out by 
means of a {mall piece of ftiff grafs, or bit of ftick, without 
hurting the pearl fifh. In this praétice they are extremely 
expert. Some of them were difcovered whilft I was there, 
and received their due punifhment. 

Gmelin afks, if the animal of the mytilus margaritiferus is 
an a/cidia ? See Linn, Syft. Nat. tom. I. p. vi. 3350. This 
induces me to believe that it has never yet beén accurately 
defcribed; it does not refemble the a/cidia of Linnzus, and 
_ may, perhaps, form a new genus, It is faftened to the upper 
and lower fhells by two white flat pieces of mufcular fub- 
ftance, which are called by Houttuin* ears, and extend 


* Vide Houtt. Nat. Hift. Vol. I. p. xv, p, 381, feq. 
Vou. VY. Yy about 


346 An Account of the Pearl Fifbery at Ceylon. 


about two iticlies from the thick part of the body, growing 
gradually thinner. The extremity of each ear lies loofe, and 
is furrounded by a double brown fringed line. Thefe lie al- 
moft the third of an inch ‘rom the outer part of the fhell, 
and are continually moved by the animal. Next to thefe, 
above and below, ‘are fituated two other double fringed move- 
able fubftances, like the branchiz of a fifh. Thefe ears and 
fringes are joined to a cylindrical piece of flefh of the fize of 
a man’s thumb, which is harder and of a more mufcular 
nature than the reft of the:body. It lies about the centre of 
the fhells, and is firmly attached to the middle of each. This, 
in faét, is that part of the pearl fifth which ferves to open and 
fhut the fhells. Where this column is faftened, we find on 
the flefh deep impreffions, and on the fhell various nodes of 
round or oblong forms, like imperfect pearls. Between this 
part and the hinge (cardo) lies the principal body of the ani- 
mal, feparated from the reft, and fhaped like a bag. The 
mouth is near the hinge of the fhell, enveloped in a veil, and 
has a double flap or lip on each fide; from thence we ob- 
ferve the throat (@/ophagus) defcending like a thread to the 
ftomach. Clofe to the mouth there is a curved brownifh 
tongue, half an inch in Jength, with an obtufe point; on 
the concave fide of this defcends a furrow, which the ani- 
mal opens and fhuts, and probably ufes to convey food to 
its mouth*. Near its middle are two blueith fpots, which 
feem to be the eyes. Ina pretty deep hole, near the bafe of 
the tongue, lies the beard (dy//us), faftened by two flefhy 
roots, and confifting of almoft one hundred fibres, each an 
inch long, of a dark green colour, with a metallic luftre ; 


* The depth at which the pearl fith generally is to be found, hindered 
me from paying any attention to the locomotive power, wnich I have not 
the leaft doubt it poffeffes, ufing for this purpofe its tongues This con- 
jeGture is ftrengthened by the accurate oblervations made on mufcles by 
the celebrated Reaumur, in whieh he found that this body ferves them as 
a leg or arm, to move from one place to another. Though the divers are 
very ignorant with regard to the cecononiy of the pearl fith, this changing 
of habitation has been long fince obferved by them. They allege, that it 
alters its abode, when difturbed by an enemy, or in fearch of food. In the 
former cafe they fay it commonly defcends from the fummit of the bark 
ro-its declivity, 


they 


An Account of the Pearl Fifbery at Ceylon. 347 


_ they are undivided, parallel, and flattened. In general, the 
éyffus is more than three quarters of an inch without the 
cleft (rima); but if the animal is difturbed, it contraéts it 
confiderably. The top of each of thefe threads terminates 
in a circular gland or head, like the jzigma of many plants. 

With this 4y/Jus they faften themfelves to rocks, corals, and 
other folid bodies; by it the young pearl fifh cling to the 
old ones, and with it the animal procures its food, by ex- 
tending and contracting it at pleafure. Small fhell fith, on 
which they partly live, are often found clinging to the for- 
mer. The ftomach lies clofe to the root of the beard, and 
has, on its lower fide, a protracted obtufe point. Above the 
ftomach are two fmall red bodies, like lungs; and from the 
ftomach goes a long channel or gut, which takes a-circuit 
round the mufcular column above mentioned, and ends in 
the anus, which lies oppofite to the mouth, and is covered 
with a {mall thin leaf, like a flap. Though the natives pre- 
tend to diftinguifh the fexes by the appearance of the fhell, 

I could not find any genitalia. The large flat ones they 
call males, and thofe that are thick, concave, and vaulted, 

they call females, or pedoo-chippy; but, on a clofe infpec- - 
tion, I could not obferve any vifible fexual difference, 

It is remarkable that fome of thefe animals are as red as 
blood, and that the infide of the fhell has the fante colour, 
with the ufual pearly luftre; though my fervants found a 
reddifh pearl in an oyfter of this colour, yet fuch an event is 
very raré. The divers attribute this rednefs to the ficknefs 
of the pearl fifth, though it 1s moft probable that they had it 
from their firft exiftence. In the fhade they will live twenty- 
four hours after being taken out of the water. This animal 
is eaten by the lower clafs of Indians, either frefh in. their 
curries, or cured by drying; in which ftate they are exported 
to the coaft; though I do nat think them by any means 

palatable. 

Within a mother-of-pearl fhell I found thirteen murices 
nydati (vide Chemnitz’s New Sy{tem, Cabt. Vol, XI. tab. 192, : 
f, 1851 and 1852), the largeft of which was three quarters 
of an inch Jong; but, as many of them were putrid, and the 
pearl fifh itfelf ie id, T could not afcertain whether they had 

Yy2 crept 


348 An Account of the Pearl Fifbery at Ceylon. 


crept in as enemies, or were drawn in by the animal itfelf. 
At any rate turtles and crabs are inimical to the animals, and 
a fmall living crab was found in one of them. 

The pearls are only in the fofter part of the animal, and 
never in that firm mufcular column above mentioned. We. 
find them in general near the earth, and on both fides of the 
mouth. The natives entertain the fame foolifh opinion con- 
cerning the formation of the pearl which the ancients did: 
they fuppofe them formed from dew-drops in connection with 
fun-beams. A Brahmen informed me that it was recorded 
in one of his Sanfcrit books, that the pearls are formed in the 
month of May at the appearance of the Soatee ftar (one of 
their twenty-feven conftellations), when the oyfters come up 
to the furface of the water to catch the drops of rain. One 
of the moft celebrated conchologifts * fuppofes that the pearl 
is formed by the oyfter in order to defend itfelf from the at- 
tacks of the pholades and boreworms. But we may be af- 
fured that in this fuppofition he is miftaken; for, although 
thefe animals often penetrate the outer layers of the pearl 
fhell, and there occafion hollow nodes, yet, on examination, 
it will be found that they are never able to pierce the firm 
layer with which the infide of the fhell is lined. How can 
the pearls be formed as a defence againft exterior worms, 
when, even on fhells that contain them, no worm-holes are 
to be feen? It is therefore more probable thefe worms take 
up their habitations in the nodes in order to protect them- 
_felves from the attacks of an enemy, than that they are ca- 
pable of preying on an animal fo well defended as the pearl | 
fifh is. It is unneceffary to repeat the various opinions and 
hypothefes of other modern authors; it is much eafier to 
criticife them, than to fubftitute’ in their place a more ra- 
tional theory. That of Reaumur, mentioned in the memoirs 
of the French Academy for 1712, is the moft probable, viz. 
that the pearls are formed like bezoars and other ftones in _ 
different animals, and are apparently the efleéts of a difeafe, - 
In fhort, it is very evident that the pearl is formed by an ex- 
travafation, of a glutingus juice, either within the body, or on 
the furface of the animal: the former cafe is the moft’ cont: 

* The Sais Mr. C bemnitz at Copenhagen, 


mon, ~ 


An Account of the Pearl Fifbery at Ceylon. 349 


mon. Between one and two hundred pearls have been found 
within-one oyfter. Such extravafations may be caufed by 
heterogeneous bodies, fuch as fand, coming in with the food, 
which the animal, to prevent difagreeable friction, covers 
with its glutinous matter, and which, as it is fucceffively 
fecreted, forms many regular Jamellz in the manner of the 
coats of an onion, or like different ftrata of bezoars, only 
much thinner; this is probable, for if we cut through the 
centre of a pearl, we often find a foreign particle, which. 
ought to be confidered as the nucleus, or primary caufe of 
its formation. The loofe pearls may originally have been 
produced within the body, and, on their increafe, may have 
feparated and fallen into the cavity of the fhell. Thofe- 
compact ones, fixed to the fhells, feem to be produced by 
- fimilar extravafation occafioned by the friction of fome 
roughnefs on the infide of the fhell. Thefe and the pearl- 
like nodes have a different afpect from the pearls, and are of 
a darker and bluer colour. In one of the former I found a 
pretty large, true, oval pearl, of a very clear water; while the 
node itfelf was of a dark blueith colour. The yellow or gold- 
coloured pearl, is the moft efteemed hy the natives; fome have 
a bright red Juftre; others are grey, or blackifh, without any 
fhining appearance, and of no value. Sometimes, when the 
grey lamella of a pearl is taken off, under it is found a beau- 
tiful genuine one; but it oftener happens that, after having 
feparated the firft coat, you find a worthlefs impure pearl. 
I tried feveral of them, taking one lamella off after another, 
and found clear and impure by turns; and in an impure 
pearl I met with one of a clear water, though in the centre 
of all I found a foreign particle. The largeft and moft per- 
feét pearl which I faw during my ftay at Condatchey was 
about the fize of a fmall piftol bullet, though I have been 
told fince my departure many others of the fame fize have 
been found. The {potted and irregular ones are fold cheap, 
and are chiefly ufed by the native phyficians as an ingredient 
in their medicines. 

We may judge with greater or leffer probability, by the 
appearance of the pearl fhell,* whether they contain pearls or 
hot, Thofe that have a thick ‘calcareous craft upon them, 

, to 


{ 


350 An Account of the Pearl Fifhery at Ceylon. 


to which ferpule (fea tubes) Tubuli marini irregulariter in- 


torti, Crifla-gali Chamar lazuras, Lepas tintinabulum, Ma-— 


dreporee, Millipore, Cellipore, Gorgonta, Spongie, and other 
Zoophytes are faftened, have arrived at their full growth, 
and commonly contain the beft pearls; but thofe that appear 
fmooth, contain either none, or fmall ones only. 

Were a naturalift to make an excurfion for a few months 
to Mandar, the fmall ifland near Jafna, and the adjacent 
coaft, he would difeover many natural curiofities ftill buried 
in obfcurity, or that have never been accurately defcribed. 

Indeed no place in the Eaft Indies abounds more with 
rare fhells than thefe; for there they remain undifturbed, by 


being fheltered from turbulent feas, and the fury of the furf. 


T will juft name a few of them; viz. Tellina foliaca Linn*, 
Fell Spenglerii, Arca culculata}, Arca Noe, folen anatinus 
Linn. Offrea Ifognomum, Terebullum, aibidum, flriatum, 
Turb fealaris t, Bula volva Linn.§, Vevxillum ingritarum, 
&c. Amongtft the beautiful cone fhells; conus thalaffiar- 
ehus Anglicanus cullatus ||, amadis thaffiarchus con. gene- 
ralcis Linn. ¢. capitaneus§, c. miles**, c. frercus mufca- 
rumtt, ¢. reteaureum, c. glaucustt, c. cereola, regia co- 
rona, murus lapidius, cauda erminea, focietas cordium. There 


are many others befides thofe already mentioned, equally va-_ 


luable and curious. 


The great fuccefs of the Rey. Doétor John in conchology 


when at Tutucorin, and affifted by G. Angelbeck, with a 
boat and divers; and the capital collections made by his 
agents, whom he afterwards fent there with the neceffary 
inftruétions and apparatus, may be feen in Chemnitz’s ele- 
gant Cabinet of Shells in 4to, (with illunnnated plates) ; and 


how many new fpecies of Zoophytes he difcovered, we learn . 
from another German work by Efper at Erlangen, the third 


volume of which is nearly finifhed, 


* The golden tong. + Mounk{cape. t Royal ftaircafe, 
§ Weaver's hutrle. _ || Red Englith admiral. 
a Green ftamper- ** Garter ftamper. 


+ Great fand {tamper. tt Capf, Gottw, 


VII, Acted 


“> 


[Manin sys, 


VII. Account of a new Method of Bleaching Cotton. By 
C. CuapraL, Member of the National Injiitute*. 


Tue happy applications which C. Berthollet has made 
of the oxygenated muriatic acid, in the bleaching of ftuffs 
manufactured from vegetable fubftances, feems to have car- 
ned this art very near to perfection; but this method is not 
every where attended with the fame degree of economy. Be- 
fides, the procefs requires very fkilful hands, that the ftuffs 
may not be deftroyed by too corrofive leys, or leys impro- 
perly employed; and therefore we ought not to omit making 
known other proceffes, in order that manufacturers may 
choofe thofe which they may think moft beneficial. I fhall 
therefore here defcribe a procefs, both fimple and economical, 
. for bleaching cotton yarn. 

At the difiance of about one foot four inches from the 
grate of a common furnace, place a copper kettle of a round 
form, one foot and a half in depth and four feet in diameter, 
and fix it in that pofition. The brim of this kettle, about 
fix inches in breadth, being bent outwards, will reft on the 
lateral edges of the mafon- work of the furnace. The re- 
mainder of the furnace muft be conftructed of cut ftone, in 
the form of an oval boiler, fix feet in height, and in breadth, - 
-meafured from the centre, five fect. The upper part of the 
furnace has a round aperture, in diameter about a foot and a 
half. This aperture may be clofed by means of a moveable 
ftone, or a copper lid made for the purpofe. On the edge of 
the copper kettle, which forms the bottom of this fpecies of 
digefter, place a kind of grate confifting of wooden bars, 
brought pretty near to each other in order that the cotton 
Jaid upon them may not fall through, and fufficiently ftrong 
to fufiain the weight of about 1600 pounds. When this 
apparatus has been conftructed, impregnate the cotton dif- 
pofed in bundles, with a flight folution of foda, rendered 
cauftic by lime: this operation muft be performed in a 
wooden or ftone trough, in which the cotton may be trod 


; * From the Bulletin des Sciences, Vol, 11, No 6. 
upon 


352 Account of a new Method of Bleaching Cotton. 


upon by fecuring the feet with wooden thoes, When the alka- 
line liquor has well penetrated the cotton in an equal manner, 
it is to be carried to the boiler, and placed on the wooden 
grate already mentioned. The fuperfluous liquor will run 
down between the bars, and form a liquid firatum, which 
will permit the mafs to be heated without any danger of 
burning the cotton or the bottom of the boiler. To form 
the alkaline ley, foda of Alicant may be employed equal to a 
tenth part of the weight of the cotton on which you operate; 
and in a boiler fuch as I have defcribed, about 800 pounds 
of cotton may be fubjeéted to the procefs at one time. At 
the moment when the cotton is introduced and arranged in 
the boiler, the aperture at top is fhut, by its ufual covering, 
as clofely as poffible, in order that the vapours may affume 
a greater degree of heat, and re-aé& with more force on the 
cotton. The fire of the furnace is then to be kindled *, and 
the ley muft be kept in a ftate of flight ebullition for from 
twenty to thirty-fix hours. It is then fuffered to cool, and 
the cotton being carefully wafhed, muft be expofed on the 
grafs for two or three days, extending’ it on poles in the day- 
time, and fpreading it out on the grafs during the night. The 
cotton will then have acquired a fuperb degree of whitenefs ; 
and if, by chance, any parts of the cotton are ftill coloured, 
it muft be put into the kettle a fecond time, or be expofed a 
few days longer on the grafs. Thefe fhades in the bleached 
cotton are owing in particular to its not having been all 
equally and completely impregnated with the ley; they may 
arife alfo from the arrangement of the cotton in the boiler, if. 
it has been heaped up too much in certain points. When it 
is judged that the ley has been exhaufted by ebullition, the 
cover of the kettle is to be taken off, and the dry cotton mut. 
be befprinkled with a new folution of foda; without this pre- 
caution it might run the danger of Baile burnt, It might 
readily be judged, by eftimating the fub tances and time 
employed in this operation, that it is attended with econo- 
mical advantages; but we have a more fimple method of af- 
* In giving the above dimenfions, I have fuppofed the fuel ufed to be 
coal : if wood is burnt, the dimenfions muft be varied. In the latter cafe 
the bottom of the kettle would be too high above the bottom of the furnace. 
certaining 


SS 


—— See 


ee Se 


Method of preparing Inks, &d. 353 
€éftaining the faét, that is, the low price at which cotton 
is bleached in all thofe manufactories where this procefs is 
ufed. In the fouth of France, where this method is at 
prefent pretty getiérally adopted, eighty pounds of cotton 
are bleached for about feven fhillings fterling. This procefs 


. was brought to us from the Levant fome time after the in= 


troduction of the procefs for dyeing the Adrianople red. It 
has been practifed for fome time, but kept a fecret till the 
efent moment, and flill known by the name of blanchimont 
& la fumée, bleaching by fmoke. 
I do ttot know that this method has been applied to the 
bleaching of fpun flax or hemp. It would, however, be worth 
while to try the experiment: ftronger leys and longer ebul- 


lition, no doubt, muft be employed; but it is by experience 


alone that we can acquire information on the fubje&. 


VILL. On the Method of preparing Inks that will withftand 
the AGiion of the Onygenated Muriatic Acid. By A. Bossn, 
of Hamburg *. 

INTRODUCTION. 


For illuftrating the hiftory of this fubje&t, which has 
been fully treated of in the New Hanoverian Magazine, 
the followmg information may be neceffary :—Dr. Lentin, 
in his paper containing cautions in regard to the mifapplica- 
tion of the oxygenated muriatic acid}, obferved, that with 
the help of this acid owr common ink could be obliterated 
without the leaft injury to the paper which had been written 
with it, if the paper were firft-drawn through diluted oxygen- 


ated niuriatic acid; then through diluted fulphurous acid; 


and laftly, through water. At the fame time he added fome 
mformation which feemed to prove that this property had 
been employed in France feveral times to anfwer private pur- 
pofes, and to the prejudice of others. Soon after appeared a 


* From Scherer’s Algemeines Journal der Chemie, Vol.Il. No. 10, 
The Introduétion is by Dr. Scherer. 
+ Hannov. Mag, 1797, part 71- 

Var. Y. Za paper 


354 Method of preparing Inks, &c. “ 
paper by Philip Chriftian Pitel of Minden *, in which he 
recommended an ink, difcovered by him, which was inde~ 
ftructible, and could be obliterated neither by the oxygen-, | 
ated muriatic acid, nor by any other. ,corrofive fubftance. 
This induced M. Wehrs to examine this ink, and the fame 
thing was undertaken by M. Gruner. According to their 
experiments, this ink, however, was obliterated in the courfe 
of nine hours by the oxygenated muriatic acid, and alfo by 
cauftic pot-afh; but at the fame time an opinion entirely 
oppofite was announced by Dr. Lentin t, M. Thorey §, and 
M. Wiegleb ||, who all, in confequence of their having em- 
ployed the fame teft, declared the ink to be indeftruétible. 
Thefe different opimions are therefore directly contrary to 
each other. M. Gruner found that the ink could be de- 
{troyed by the oxgenated muriatic acid, and by cauftic al- 
kali: M. Thorey obferved, that its blacknefs was only lef- 
fened by the oxygenated muriatic acid, and by the vapour 
of that acid. He found, however, as M. Gruner did, that the 
cauftic alkali diffolved the ink entirely from the paper,. but 
that, like feveral acids, it deftroyed the paper. M. Lentin and 
Wicgleb deduced from their experiments, thofe of the for- 
mer cbairig made with oxygenated muriatic acid, ‘and thofe 
of the bidet with the fame, as well as feveral other acids, and 
even cauttic alkali, that this ink was entirely indeftructible. 
Thefe contradictory refults M. Weftrumb endeavoured to re- 
folve in his examination of Pitel’s indeftru@iible ink, which 
he found to be only common ink mixed with indigo; and he 
propofed the following mixture for an ink which could not 
be deflroyed :—Boil 1 0z. of Brafil wood, and 3 ozs. of pul- 
verifed galls, with 46 oz. of water; ftrain the liquor, which 
mutt be boiled down to. 32 ozs., and pour it, ftill warm, over 
14 oz. of perfectly pure fulphate of iron, 14 oz. of gum ara- 
bic, and 2 0z. refined fugar. When thefe ingredients are 
diflolved, add from 1 to 14 02. good indigo ground exceed- 
ingly fine, and 3 oz, of purified lamp black. 


* Hannov. Mag. 1797, part 77. + Ibid. t Ibid. p. r223. 
§ Ibid.1797, part 97. || Reich’s Anzeiger 1797, No- 297. 


M. Bossx’s 


es: 


Method of preparing Inks, &c. 355 


M. Bosset’s PAPER. 


It is well known that M. Pitel, of Minden, gave the firft 
account of a kind of ink which withftood the oxygenated 
muriatic acid, at the defire of Dr. Lentin, who excited the 
attention of the public to various deceptions practifed at Paris 


‘with common ink by means of the oxygenated rmuriatic acid. 


As this ink confifted merely of a decoction of logwood and 
galls with water, in which fulphate of iron, gum arabic, and 


fugar had been diffolved, and with which indigo and lamp 


black had been mixed mechanically, according to the ana- 
lyfis of M. Weftrumb, it may be eafily explained why it exhi- 
bited fuch different appearances when brought to the teft. 
M. Gruner, apothecary in Hanover, as appears by his letter 
to the editor of the Hanoverian Magazine, was able to obli- 
terate it entirely by the muriatic acid; while, on the other 
hand, its indeftruétibility by that acid is confirmed by 
M. Wiegleb and Thorey. Both are in the right: as foon 
as the ink is well ftirred round, it withftands this acid; but, 
if not ftirred, this acid diffolyes the black oxyd of iron, and 
the paper in the places wrote upon is reftored to its prif- 
tine ftate. Now, though this ink, when ftirred round, does 
not entirely fail of its objec, this circumftance, however, 
may be often forgotten ; and this the more readily, as even 
without ftirring it has all the blacknefs when ufed of com- 
mon ink, on account of the oxyd of iron which it contains. 
Since that time I have made experiments in order to produce 
an ink which might with{tand the oxy-muriatic acid, and yet 
contain no iron. I have been able to accomplith this, as well 
as the compofition of fome other inks which contain iron, 
though it does not make their chief component parts, but 
ferves only to give the ink a black colour. 1 made experi- 
ments alfo with the juice of green plants, according to the 
procefs by which M. Murray made an indeftructible kind of 
ink from the fame fubftances. ~ Iron muft not be the chief 


component part of an ink deflined to withftand the muriatic 


acid, becaufe in the ftate of a black oxyd it is eafily diffolved 
by the acid. But as it acts on vegetable colours only when 


they are capable of taking up oxygen, and does not deftroy 


ZZ2 them, 


356 Method of preparing Inks, &c. 


them, but produces by its action a modification of the coe 
lour, they are exceedingly proper for this purpofe. As none 
of thefe, however, were found entirely black, I was obliged 
to employ fome mineral body which might be black and 
yet hold a great deal of oxygen. The moft part of the me- 
" tallic oxyds of a black colour contain very little oxygen, ex- 
cept that of manganefe, which contains a great deal. I made 
choice therefore of this oxyd, and found, after repeated ex- 
periments, that it anfwered the intended purpefe. 

The oxy-muriatic acid diffolves all metals in a metallic 
form as well as metallic calces combined with a {mall quan- 
tity of oxygen, but not thofe which contain a great deal, as 
it has itfelf an excefs of it. It is therefore capable, 

1. Of diffolving metals in a metallic ftate, as the metals 
take up its fuperfluous oxygen, by which, as is well known, 
they become foluble in acids. 

2. Such metallic oxyds as contain little oxygen are capable 
of abftraGing it from acids, and they then diffolve in the 
acids, which then contain lefs oxygen, 

The grounds which induced me to employ oxyd of man- 
ganefe for preparing an ink capable of withftanding the oxy- 
muriatic acid, were as follows :— 

x, Its black colour; 2. its containing a great quantity of 
oxygen, by which it is infoluble in the muriatic acid; 3. be- 
caufe it poffeffes fo great an affinity for oxygen, that whenever 
it has loft any of its original quantity by being brought to 

a red heat, or expofed to the action of acids, it icamndediately 
draws it ay the atmofphere, and again becomes black. I 
fhall now defcribe the method of preparing this ink :—Boil 
1 oz. of Brazil wood with 12 ozs. of water for a quarter of an 
hour; add 4 0z. of alum: evaporate the whole to 8 ozs., and 
mix with the liquor 1 0z. of exceedingly foft, finely pulverifed 
manganefe, mixed up with 4 oz. of pulverifed gum arabic. 

Brazil wood alone, by mere boiling, gives an ink not al- 
together unfit for ufe. Acids, lefs abundant in oxygen, fuch 
as the nitrous and muriatic acid, naturally exercife amaétion 
on this ink; but as thefe change the paper in a perceptible 
manner, deception is not to be apprehended. xf 

Indigo alfo affords an ink that withftands the muriatic 

acid : 


Hiftory of Mining in Devon and Cornwall. 337 


acid: it therefore makes a chief component part of that pre- 
pared by Pitel, but it is mixed in it only mechanically. The 
following is a prefcription for preparing an ink of the like 
kind, but in which the indigo is actually diffolved. é 

Boil.1 oz. of Brazil waod, and 3 ozs. of coarfely pulverifed 
galls, with g ozs. of vinegar and as aeudh water, for the {pace 
of eight minutes: in the liquor, after being ftrained, diffolve 
1 0z. of fulphat of iron and 1 oz. of gum arabic, and'then 
add to the whole a folution of 1 0z. of indigo m I oz. of 
concentrated fulphuric acid. 

The oxy-muriatic acid diffolves the oxyd of iron in this 
ink, but the indigo remains undecompofed. The principal 
point to be attended to is, that the ink may contain fuch 
‘matters as are not affected by the oxy-muriatic acid: with 
other fubftances lefs deception is to be dreaded. 

In the laft place, I fhall mention an ink made with the 
principal ingredients of common ink, but in preparing 
which, inftead of the ufual liquids, I employed the exprefled 
juice of fome plant: the fitteft for this purpofe I found to 
be the leaves of the caper {purge, Euphorbia lathyris LInn.; 
the common holly, Sambucus niger, and common grafs. 


IX. Sketch artis Hiftory of Mining i in Devon and Cornwall, 
By Mr. Joun Taytor jun. Miner, Tavijlock. Commu- 
municated by the Author, 


a mutt be regretted that a fubje& of fo great national im- 
pertance, undertakings which engage fo large a capital, and 
give employment to fo many hands, as working the various 
mines in thefe kingdoms, fhould gain but little attention 
from any but thofe immediately concerned in them, and near 
the places in which they are fituated; it is the more to be 

_wifhed that men of fcience fhould devote fome thought to 
thefe concerns, as thofe, under whofe management moft of 
thefe works are carried on, are often not men of fufficient 
ability or feience to ftrike out capital improvements. To be 
a good miner requires an active mind, with induftry and 
rit obfervation; thefe fhould be accompanied by fome 

general 


358 “Sketch of the Hiflory of 


general knowledge, at Jeaft, of praétical mineralogy, che- 
miftry, mechantes, hydraulics, &ce., and fuch a knowledge 
of principles as might lead to improvements in the practical 
part of ms bufinefs. It would be unreafonable to expe& to 
find thefe qualifications general at prefent, but the exifiing 
¥gnorance might furely be foon removed, if, the attention of 
men of fcience being turned to the fubject, they would take 
“pains to point out to the praétical miner the improvements 
ef which his operations are fufceptible. 

If it be true, as was afferted in the number of the Philo- 
fophical Magazine for February laft, ** that the pooreft mine 
in Cornwall is worked at a greater expence than the richeft 
one on the Continent,” much is to be done; although to 
work a mine rich or poor to the fame extent muft require 
the fame expence.. From my own experience I cannot af- 
fent to what is afierted, in the fame paragraph, of the cap- 
tains or directors of the Cornith mines; I can bear teftimony 
to there being among them men of ability, obfervation, and 
liberality ; of all the prefent practical knowledge of the fub- 
jeét many of them are perfect mafters, and have not often, 
I think, that defire of excluding interference which is in1- 
puted to them. 

Mining is a fubjeCt requiring ftudy, and deferving the at- 
tention of the philofopher, as it tends to unveil fome of the 
molt hidden procefles of Nature, and to anfwer important 
ends to Society. On the Continent many of the moft emi- 
nent men have not thought it beneath them to undertake 

the management of mines; and to this it is fair to impute 
the capital manner in which fome foreign mines are reported 
to be conducted, 

‘Tt muft afford pleafure to know that of late years many 
improvements in mining, as well as in moft other arts con- 
nected with or depending on the feiences, have taken place ; 
and both the difcovery of the ores, and their treatment after 
being brought to the furface, is, in moft refpects, carried on 
with greater certainty and {kill, and confequently more profit. 

It may afford fome amufement to attend a little to the hife 
tary of this fource of the moft ancient traffic of our ifland, 
and the cayfe, probably, of much of our civilization, it having 

, attracted, 


Mining in Devon and Cornwall. 359 


attracted, long ago, the vifits of other more enlightened 
nations. 

The tin, of Britain was known in diftant parts of the world 
at a very remote ‘period. It is generally believed that the 
Pheenicians were the nation principally engaged in trading 
with Britain for this article. Tin works were certainly car- 
ried on before iron was in ufe in England. Many tools of 
oak are now found which tradition among the tinners make 
to have belonged to the Saxons or Danes ; but it is probable, 
for the reafon before ftated, that they were employed before 
the time of their having a footing in this country. 

The greateft quantity of tin was formerly, it is afferted, 
found on the foreft of Dartmoor, in the county of Devon; 
and works to a vaft extent muft have been carried on there, 
if it be true, as we are told, that thirty thoufand men found 
employment upon this tract; for all the miners now in Corn- 
wall do not amount to more than ten thoufand. It is, how- 
ever, to be confidered, that in the ancient mode of working, 
without the aid of machinery, many more hands muft have 
been neceflary than at prefent—I fhould think more than in 
the proportion of three to one. All thefe works on Dart- 
moor were only on or near the furface: now, however, the 
lodes * or veins of tin found on this diftriét are not valuable 
enough, or do not continue to fuch a depth as to make them 
very profitable to work. 

’ Almoft all the tin procured in former ages was probably 
from. fiream-works, in bottoms or low grounds, where frag- 
ments of the ore, wafhed from the Jodes in the neighbouring 
hills, fubfide, and are feparated from the earth in a granu- 
lated form by wafhing. This, of courfe, is obtained without . 
any fubterranean work. In fuch fituations as thefe probably 

metals were firft difcovered, mixed merely with the upper 
foil, or lodging in. clefts of rocks. Thus is gold found in 
America, in Africa, in the county of Wicklow in Ireland, 
and fo has it been occafionally difcovered in Cornwall; and 
veins or lodes of this metal might doubtlefs be found near 
the places where fuch depofitions are met with. 

The tracing and following lodes of ores into the earth is a 


* The name given in Cornwall to veins in which ore is found, 


; 9 more 


360 Sketch of thé Hiftory of | 


more difficult tafk than coming at the metal in the way of 


ftream-works ; it requires more energy of mind, and a moré- 


advanced ftate of the arts. The difficulty that mutt attend 
keeping a mine, funk to forte depth, free from water by 
manual labour only, could not but prevent men, before the 
application of machinery, from diving deep into the bowels 
of the earth. We have, however, fome inftances where old 
workings are found at fo great a depth as to be even now 
with difficulty kept dry by means of machinery; but thefe, 
though they may be counted ancient, were probably opened 
long fubfequent to the origin of mining in this county, 

There are many mines which could not poflibly be worked 
without the aid of gunpowder, and, until the difcovery of 
this powerful agent, underground operations muft have been 
uncertain and difficult. The hammer and wedges of metal 
were probably the firft inftruments for fplitting rocks (and 
they ftill continue, in the ground that will yield to them, to 
be much ufed in Cornwall), and the pick, or inftrument for 
cleaving the ground, having a head for driving the wedges 
called by the miners gads, from a Cornifh word gedn, a 
wedge. The form of thefe inftruments found in old works, 
I think, offers an evidence of their antiquity. A pick, which 
was found in Wheal* Unity tin mine, in Devon, in a part 
not worked certainly for more than eighty years, and which 
could not probably be reckoned to be Jefs than 100 yeats 
.old, does not differ matérially from the form of that now 
ufed; while one difcovered in old workings in Drake Walls 
mine, in the parifh of Calftock in Cornwall, about ten miles 
diftant from the other mine, is of fo différent a fhape as to 
make one conclude, judging by the flow progreffion of 
changes effe€ted on comimon inftruments, that it is of much 
higher antiquity. Wedges of dry wood were alfo very inge- 
nioufly made ufe of, by driving them inio the clefts, and then 
wetting them, fo as to caufe them to fwell and force the 
ground afunder. Tire was an agent long ago employed for 
fplitting the rocks; but the effects of eunpowder fo far exceed 
any thing before made ufe of for fuch purpofes, that its-dif- 
_* In this part of the country the word wheal, fiynifying in the Cornith 

Janguage a work, is generally prefixed to the proper names of mines. 
€ covery 


Mining in Devon and Cornwall. 361 


covery and application to works of this kind form a grand 
epoch in the hiftory of mining. This, it appears, took place 
in Hungary or Germany about the year 1620, and was firft 
introduced into England at the copper mine at Eéton, i in 
Staffordfhire, ecalee the year 1670, by German miners, 
brought over by Prince Rupert; but it was not in ufg in 
Somerfetthire till 1684, after which, probably, the Cornifh 
miners became acquainted with this powerful afliftant to 
their operations. 

Tin was the firft obje& of the Cornifh miner’s fearch, and 
I fhall therefore firft take notice of the hiftory of the tin-works. 
It was probably firft found, as I have obferved, near the fur- 
face, and not in regular veins; alimoft all the low grounds in 
Cornwall, and I believe every bottom on Dartmoor foreft 
in Devon, bear the marks of having been /lreamed. The 
Romans, probably, interefted themfelves in the working of 
the mines; indeed, one principal inducement to that people’s 
turning their attention to this ifland, feems to have been the 
metals that were reported to them to be found kere. The 
Saxons neglected thefe hidden treafures, but the Normans 
worked them to great advantage. From that time to the end 
of the reign of John the mines were not profitable, and 
moftly in the hands of the Jews. They revived in the 
time of his fon Richard; but in the reign of Edward I. the 
Jews were banifhed the kingdom, and the mines neglected. 
Edmund, the eldett fon of the king, and earl of Cornwall, 
however, made fome important alterations in the regulations 
of the tin-works by a charter, which was confirmed by Ed- 
ward I. in the latter part of his reign. Indeed it is from this 
time that the peculiar Jaws and privileges relating to the 
Stannaries are chiefly to be dated. Mining infr inged j in fome 
iiftances on property, and caufed bifennecs befides requiring 
indulgences not general; and thus cafes arofe not cognilable 
by the common law. In this way a peculiar code, fpringing 
from cufiom, took its rife; and though this in fome mea- 
fure exifted before, yet it was not till this period that it was 
confirmed by royal charter, and enforced by fubfequent acts 
of pafliament. It was by this charter that the bounding 
Jgnd to the purpofe of tinners working on it, the duties to 

VoL. V. 3A, the 


362 Sketch of the Hiflory of 

» the earl of Cornwall, and the coinages of tin, or ftamping 
with the earl’s feal, were firft eftablithed. Before the reigm 
of Edward I. tinners worked in the earl’s land only, paying 
him a fifteenth part of what they got, and they were not at 
all permitted to dig in fanétuary ground, churches, ‘mills, 
houfes, gardens, and fo on; and if in working under they 
chanced to fubvert any houfe, or to damage a highyway, 
they were obliged to make it good. When it became an 
object to fearch throughout any place or perfon’s lands, a 
court alfo to determine cafes relating to the tin-works be- 
came heceffary ; and this, adjudging meine the authority of, 
and according to the code of laws before mentioned, was 
firft eftablifhed by Edward I. and is called the Stannary 
Court. 

In Cornwall and Devon two different fyftems of Stannary 
laws now exift: thofe in Cornwall have been from time to 
time amended and correéted ; but in Devon, where mining 
has for a long while flumbered, the laws continue in their 
original crude ftate. As the fpirit, however, of fearching 
mto the bowels of the earth feems again to be reviving in 
this county, the laws, fhould they be called into action, will 
probably undergo fome revifion. 

The duke of Cornwall had royal jurifdi&tion; and when 
the duchy came into the hands of the crown, which hap- 
pened in the reign of Edward III. he made his eldeft fon, 
the Black Prince, the duke, and appointed it, with the re- 
venue arifing from it, to the fons and heirs apparent of the 
crown, though no fon of the king can be duke of Cornwall 
but the firft-born, even though heir apparent. 

The Stannary Jaws were explained and confirmed, with 
fome alterations at different times, till Arthur, eldeft fon: of 
Henry VIII. made certain conftitutions relating to the Stan= 
naries, which the tinners refufed to:obferve: the king, after 
prince Arthur’s death, feized the charter as forfeited, ‘but 
granted a new one with frefh privileges, appointing all new 
laws relating to the tinners to be made by a parliamentiof 
their own body ; and upon this footing the emia re- 
main. ; ; 

Great powers have ide at times affumed by this jot: 

tion, 


a eS ee ee 


Mining in Devon and Cornwall. 363 


tion, it has even taken upon it the trial for felony in the cafe 
of a tinner; in general, however, the cafes where its autho- 
rity interferes, are in difputes concerning tin-works or be- 
tween tinners: it provides a fupply of water to a tin-work, 
giving a power to conduét it through any lands for that pur- 
pofe. 

One of the improvements, with regard to tin particularly, 
was the invention of {melting in reverberatory furnaces with 
pitcoal, inftead of the old blowing-hou/es, as they were called, 
with charcoal fires. When this change was.firft introduced 
is not perhaps certainly known: Dr. Watfon, in his Che- 
mical Effays, ftates, that Becher refided in Cornwall fome 
years before he died, which was in the year 1682; and that 
he made many improvements in the working of mines and 
fluxing of metals, and introduced there the method of 
fmelting tin by the flame of pitcoal thrown upon the ore in a 
reverberatory furnace, inftead of the fire of wood or chareoal, 
in the way formerly made ufe of. He takes notice of this in 
the Dedication to Mr. Boyle of his Alphabethum Minerale, 
written at Truro in 1682, not long before he died. Pryce, 
in his Mineralogia Cornubienfis, ftates, that this mode was 
firft prompted by necefflity, and many experiments were 
made upon it by Sir Bevil Granville, of Stow, in the time 
of Charles I. though it was not effectually done till the reign 
of Queen Anne. 

I find, in the revifion of the Stannary laws at the convo- 
eation of the parliament of Stannators affembled in the 26th 
year of the reign of George II. mention is made of the 
** ancient laws and conflitutions of the Stannaries relating 
to tin-blowers, and refining of tin in blowing-hou/fes, which 
was formerly the only method of refining of tin;” and it is 
faid, “‘ of late years there has been another method found 
out of refining of tin by means of reverberatory furnaces, 
which is commonly called {melting of tin.” 

Copper, of which fo much is now fent from this part of 
the country, was not an objcét attended to, till a compara- 
tively late date, by the Cornifh miners: eyen in tin mines, 
which as they deepened produced copper, as is often the 
eafe, and where they needed to raife this ore, it was thrown 
by as of no value, going by the name of poder. Thofe who 

Fu2 live 


364 Sketch of the Hiflory of > 
live in the prefeat more enlightened period, are now reaping 
profits left to them by the ignorance of their forefathers. 
This proves of what confequence it is to determine, if poffi- 
ble, the value of all the fubftances pafling under the miner’s 
obfervation. 

Copper, however, was probably worked at a remote period in 
Wales, at the Parys mountain, which indeed is fuppofed to de- 
rive its name from the Celtic word praas, brafs or precious me- 
tal; and this would offer a proof of its having been worked 
by the ancient Britons. It was not attended to, or at leaft 
not well underftood, in England, till the reign of Queen Eli- 
zabeth, who paid great attention to the mines of the king- 
dom, and, by granting great privileges to Daniel Hough- 
fetter, Chrifiopher Schutz, and other Germans whom fhe 
invited into England, commenced and eftablifhed the highly 
valuable and important bufinefs of finding and purifying this 
ufeful metal. ‘To thefe foreigners, too, is owing the flourifh- 
ing ftate of our brafs manufactorics. In this reign Parys 
mine was granted to patentees, but was not worked, at leaft 
to any advantage, for a century and a half. 

The copper mines of Cornwail now are works of great 
magnitude, and fome have been funk to an amazing depth, 
and are kept working at a vaft expence. The quantity of 
materials conftantly ufed forms an extenfive commerce te 
this part of the kingdom ; and this, as wefl as the mines 
themfelves, gives employment to numbers, 

The other metals are not found in Cornwall in great 
abundance. Lead, with filver contained in the ore, is found 
in fome places; and in Devonfhire, on the borders of this 
county, a very large mine at Bere afforded galena very rich 
in filver. It was formerly worked as a royal mine, but after- 
wards lay idle a long time. It has fince been feebly tried 
but though a fteam-engine was on it, they could not go fo 
deep as it had been before funk without more power to draw 
the water, and not finding much valuable return, the mine 
has been lately ftopped again. Veins af lead ore fometimes 

~ fun with copper lodes. ; 
Tron is found-in fome places, but not in large quanti- 

ties; and coals being diftant, it will not repay the calt of pro+ 
curing. 


The 


ee 


Mining in Devon and Cornwall. 365 


The ores of many of the femi-metals, as zinc, cobalt, 
arfenic, manganefe, &e. are feattered in difierextt places, and 
of late have received attention. 

‘Mining has been much improved within this century. 
Till about a hundred years ago, the water was drawn from 
the mine by dint of humen labour; but within thefe feventy 
years the application of hydraulic engines has become gene- 
ral. The introduétion of the fteam-engine formed a grand 
gra in the annals of mining; as in many fituations no other 
power, that could be commanded, could poffibly work the 
pumps neceffary to raife the water from the bottoms: the 
confequence has been, that many mines have been worked 
that were formerly abandoned as impoffible to be profecuted. 
Other improvements of late years have been creeping in; 
the drefling of ores, or properly feparating them from the 
earths, &c, in which they lie, is much better managed than 
formerly. 

Great fpirit is to, be feen in the works in Cornwall; pro- 
digious fums are laid out in erecting powerful machinery, 
fometimes even before any quantity of ore is feen. This 
often well repays thofe who expend it, efpecially if done 
under the direction of experienced and fkilful managers, who 
are good judges of the appearances and fymptoms on which 
is founded the expectation of finding a valuable return. 

The very {pirited and laudable exertions that are making, 
at a great rifk, to bring to the public ufe fo valuable an 
article as the copper mines produce, have lately been damped 


_ by fhutting up the channel of trade with regard to this com- 


modity. The purpofe for which this is done, namely, a re- 
duétion in the price, cannot in the end be anfwered; for 
even fhould that for a time take place, the deep, and confe- 
quently expenfive mines, and thofe which produce ores of 
inferior quality, will probably be ftopped; and thus, a {maller 
quantity coming to market, the price muft again advance, 
perhaps higher than it now is. In the mean time, fhould 
it operate ta reduce the price, a valuable fource of traffic will 
be loft to the nation; the revenue will fuffer; individuals be 
diftreffed ; and numbers of people not ufed to any other way 
of life become deftitute of the means of exifience, 

. X. On 


f 396 = 
als l \ 
Xv Ontive ribatidl Pro}ortions of Coals and Ir on-Stones wfed 
at the Blafi-Furnace, and of their proper-Application tor 

Ue. By Mr. Davip Musuet, of the Clyde Iron- 

Works. | Communicated by the Author. i : 

i bint i oe 
] N the fmelting operation a juft proportion and affociation 
of materials and mechanical conftruction ought to be blended 
in order to produce the ‘belt’ poffible ‘effets. Under the 
former are comprehended the cokes, iron-ftone, limeftone, 
and blaft; ‘by the latter 1s underftood the furnace, the power 
of the blowing-machine, or the compreffion and velocity 
under which the air is difcharged into the furnace, and the 
genius or mechanical’ fkill. of ‘the workmen. According to 
this divifion T fhall endeavour to point out the very various 
effets which difproportion in: any, cafe produces, and vice 
verfa. 

"In the preceding papers the coal and iron-ftone Hate siden 
traced through their various ftages of preparation, and that 
fare pointed out in whicly they were moft fuitable for the 
pieabte manufacture of the metal. It will be neceffary to 
¢earry‘along with us this fact, that m the exact proportion 
which the quantity of carbon bears to’ the quantity of metal 
in the ore, and its mixtures, fo will be the fufibility, and of 
courfe the’value of the pig-iron obtained. The importance 
of this truth will ftill farther appear when we confider the 
very various qualities of pit-coal, the different proportions of 
carbon which they contain, and the various properties at- 
. tached to every fpecies of this ufeful combuftible. 

Amons the many ftrata of coal which I have diftilled, 
fome TF have found to contain 70 parts in the roo. This 
large proportion is peculiar to the clod-coal, ufed at fome 
of the iron-works in England, and juftly preferred, for 
the purpofe of manufacture, to the purelt and hardeft variety 
of fplint-coal. - The latter I have found to average from 560 
to 59 parts of carbon, in the 100; and the foft, or mixed 
qualities of’coal, from’ 45 to 53 parts. ‘Such vatious propor- 
tions of carbon plainly point out, that the operations to be 
followed at’each individual iron-work ought not to reft upon 

7 precedent, 


a4 . 
hy a ¥ \ 
re 


On the Proportions of Coals and Iron-Stones. 367 


precedent, unlefs ‘borrowed from thofe works where exactly 
the fame quality of coal is ufed. This analyfis alfo lays open 
part of the fource from whence originates the widely dif- 
ferent quantities of metal produced per week at various’ blaft- 
furnaces, and the great mpedprapersang of ore ufed to different 
coals. 

_ Experience has fhewn that the three qualities of coal jut 

mentioned, will {melt and give carbonation to the following 

proportions of the fame {pecies of torrefied iron-fione :— 

» 21212 \b. of clod-coal cokes will fmelt - - _ 130]b, 
r1i2]b. of fplint-coal cokes will fmelt —- -.. 1051b. 
112 lb. mixed foft and hard coal cokes will fmelt . 84]b. 
Let the iron-ftene be fuppofed in the blaft-furnace to yield 

40 per cent. then we find that the 1-20th of a ton of the re-— 

fpective qualities of cokes will fmelt and carbonate the fol- 

lowing proportions of iron, viz.—1121b. clod-cval cokes, 

130 1b. iron-ftone, at 40. per cent. = 52 1b. iron; 1121b. of 

fplint-coal cokes, 105 1b. of the ftone = 42 1b. of iron;, and 

112!b. foft and hard coal cokes, 84]b. of the iron-flone — 

= 33 & lb, of iron.» We then have for the quantity of metal 

produced by one ton of each quality of cokes : 
speGledscoall; 52 . X20 = 1040lb. 
fol %o .<1 Splint ditto. 42); X,20 =  84olb. 
os «> Mixed ditto, 68 B2er%Z04=,, 702 1b. 
This furnifhes a datum whereby we eafily obtain the quan- 
tity of the, various’ cokes neceffary, to produce 1.ton of car- 
bonated.crude iron bycommon proportion: for if 1c401b.— 
of metal are produced by 1 ton, or 22401b. of clod-eoal 
cokes, the quantity of the fame cokes requifite for the pro- 

duGtion of 1 ton; or 2240 lb. of metal, will be: rc. 9.14 

e 80. 4824°6lb. =2 3.08 

Splint-coal cokes) $402.2240 :3,2240: 5973°3lb. = 2 1g Ig 

. Mixed ditto 902462240 332240: 7147°51b. = 3.53.39 
» If to the quantity of cokes neceflary to manufacture 1 ton 

of crude ivon, we'add the quantity of volatile, matter driven 
off in the procefs of charring, which may be thus eftimated 
upon the ayerage of each quality.; oa 


5 


Clod,coal 2.07 37 |-per c. produce in cokes $ @ 62%. per ¢. 
Splint coal + — 50 £08 0% 's 
Mixed coal 3 — 62,5 ———— 3 39% 


Then, 


368 On the relative Proportions of Coals and 


Then, for the quantity of the refpeétive coals ufed in the 
raw ftate, we have the following refults in proportion:— 


T. C. Q be 
Clod-coal 5:4824°6 :: 8: 77193 = 3 8 219 
“Splint-coal 4: 59733 :: 8: 11946 = 5 6 218 
Mixed coal 3:7147°1 :: 8 : 19158} = 8 11. 0.16 


Thefe great difproportions of quantity, ufed to fabricate 
"Aton, or 2240 averdupoife pounds of the fame quality of 
crude iron, will convey a ftriking and impreffive idea of the 
multifarious qualities of coal which may be applied and 
made to produce the fame effects. It fhould alfo convince 
the manufacturer that the ftudy and analyfis of his own ma- 
terials is the firft and radical approach to true knowledge, 
and certainty of operation. Diveft him of this knowledge, 
and view him guided by the cxfloms and rules prevalent at 
another manufactory, where the coals and ores may be as 
different as has been already mentioned, and we will no 
longer wonder at the uncertainty of his refults, and the num- 
berlefs errors of his direétion. 

Before I enter into the praétical difcuffion of the applica- 
tion of coal, I beg leave to indulge myfelf in the following 
calculations :—We have already feen that the production of 

2240 lb. of carbonated crude iron requires 4824 lb. of clod- 
coal cokes; thefe may be averaged to contain 4°5 per cent. of 
afhes, which, deducted from 4824, gives'4607 Ib. of carbon 
ufed for 1 ton of metal: this fum, divided by 2240, farther 
gives, for 1 tb, of caft iron thus a vaPSAI tte 2" 058 Ib. of 
carbon. 

We next find that 2240]b. of the fame metal requires of 
fplint-coal cokes 5973°3 !b.; we farther find, from a table of 
the analyfis of coal, furnifhed in a former paper, that 100 
parts of the raw coal contained 4°2 parts of afhes. As it is 
there ftated to lofe 50 per cené. in charring, 100 parts of 
cokes will contain 8-4 of afhes; and 8-4 per cent. deducted 
from 5973°3, gives 5472 ]b. of carbon. This again, reduced 
by 2240 |b. gives for each Ib. of metal manufactured, 2°442 1b. 

Again, 71471 lb. of cokes produced from foft mixed coals 
are confumed for every ton of 2240 averdupoife pounds of 
crade iron produced; every 100 parts of the fame coals con- 

tain 


Tron-Stones ufed at the Blaft-Furnace. 369 


tain 3°3 parts of afhes; and 100 parts of cokes contain nearly 
6°5 per cent. of alhes, which, deducted from 7147°3, gives 
6672°6 of carbon, which divided by 2240, gives, for the quan- 
tity ufed for 1 1b. of caft iron, 2°9g781b.  * 

From thefe calculations it appears, that 2240 lb. of carbo- 
nated iron, requires of carbon from clod-coal 4607 1b.; of 
carbon from fplint-coal, §4721b.; and of carbon from mixed 
coal, 6672 1b.: that 1 lb. of carbonated iron requires of car- 
bon from clod-coal cokes 2,056 lb.; from fplint, 2,442 Ib. ; 
from mixed, 2,983 lb.: and that carbonated crude iron may 
be obtained when widely different quantities of carbon have 
been confumed. 

In feeking for a folution of the latter fut, we muft have 
recourle to the different degrees of inflammability of the car- 
bon, according to the various laws of continuity impofed upon 
it in its foffil conftru@tion. It can eafily be conceived, that, 
owing to this ftruéture, and the nature of the mterpofed 
afhes, the particles of carbon of fome cokes will be more 
eafily oxygenated than thofe of others ; in the fame way that 
we find fplint-coal, when expofed to ignition in contact with 
open air, affords 1-3d of more cokes than are obtained from 
foft mixed coals, though the latter, when diftilled, yields more 
pure carbon than the former. 

By experiment it is proven, that roo grains of carbonic 
acid gas is compofed of 72 parts of oxygen united with 28 
parts of carbon: if the quantity of the carbon of clod-coal, 
viz. 2°056 |b. ufed for the manufacturing of every pound of 
caft iron, is reduced to grains, we will find it to confift of 
14392 grains; this, divided by 28, gives the acidifiable prin- 
ciple of 514 X 100 = 51400 grains of carbonic acid gas *: 

* This is fuppofing, for the moment, that the whole of the carbon is 
oxygenated, either by the oxygen contained in the ore, or obrained from 
the difcharging-pipe by the decompofition of the atmofpheric air: this, 
however, is not ftriétly true, as the metal takes up a fmall portion, by 
weight, of the carbon; and when, by accident, moifture has been intro- 
duced into the furnace, either through the medium of the blaft, or of the 
materials, its decompofition furnithes a portion of both oxygen and hydro 
gen, wbich may diffolve, and alfo carry off, a part of the carbon. Atmo- 


fpheric air being found to hold water in folution, a fimall quantity of hy- 
drogen will, even in the driet weather, be prefent in the blaft-furnace. M. 


VoL, V. 3B hence, 


370 On the relative Proportions of Coals and 


hence, as 1 cubic foot of this gas, at 29°84 of barometrical 
preflure, and 54°5, of temperature, weighs nearly 761 grains, 
we find, that in the formation of every pound of caft iron 
51400 

961 
~ formed ; ait in the produétion of 1 ton of metal, the afto- 
nifhing quantity of 151289,60 cubie feet. This quantity, 
however incredible it may feem, is only what would be 
formed under the above preflure, and at the above tempera- 
ture: when we take into the account the high temperature 
at which the decompofition and scope mation are effected, 
with the confequent increafe of elaftic force and of volume, 
our ideas are almoft unable to commenfurate the fum of the 
gas hourly formed, and thrown off, ignited to the higheft de- 
gree of heat. 

If the fame mode of calculation is adopted with the other 

qualities of coal, we will have the following refults :— 


17094 
28 


= 64,54 cubical feet of carbonic acid gas will be 


For the fplint-coal 2,442 Ib. or = 610,5 X 100 


: Ay se : . 1. (OLORS 
= 61050 grains of carbonic acid, which gives 2 
I 


\ 


i 


82,85 cub. feet for 1!b., and 82,85 x 2240 = 185,584 cub. 


; 20881 

feet for r ton. For the mixed coal 2,983 or = —- = 710 x 
; ete .. 41000 

100 = 71000 grains carbonic acid; that 1s, 7 ane = 9333 


cubical feet for 11b.; and 93,3 X 2240 = 208,992 cubical 
feet for 1 ton. By the fame calculation we may attain a 
pretty accurate notion of the quantity of atmofpheric air ne- 
ceflary to produce 1 |b. or 1 ton of caft iron; an average of 
the three varieties of coal will be fufficiently accurate for this 

: 14392 + 1700< 20881 

this purpofe ; thus EAs Mee RENAL Soe A ae 174555 OF 
2,4935 lb. of carbon are confumed upon the average of each 
pound of pig- iron : this is found to produce of carbonie acid 


ee igs 


gas = 62°341 X 100 = 62°30041 grains; which 


again divided by 761, the grains in one cubic foot gives 81°86 
cubic feet for the gas difcharged in manufacturing one pound 
7 of 


‘Tron-Stones ufed at the Blaft-Furnace. 37% 


of caft iron. As carbonic acid contains, as has already been 
noticed, 72 parts of oxygen in 100, then we have for the 
quantity of oxygen gas 100: 72 :: 62300°41 : 44856°29 
grains oxygen gas; and as, at the ordinary temperature and 
preffure of the atmofphere, a cubic foot of oxygen gas weighs 
591 grains, we find 44856'29 divided by 591 = 75°89 cubic 
feet of oxygen gas neceflary to form the acidifying principle 
of 81:86 cubic feet of carbonic acid gas; and that the fame 
quantity of oxygen gas is neceflary to the production of one 
pound of carbonated crude iron. This leads us to the fol- 
lowing ftatement for the quantity of atmofpheric air ufed 
during the fame operation; firft premifing that the confti- 

. tuent parts of atmofpheric air are nearly 73 of azote and 
27 of oxygen gas; of atmofpheric air then neceflary, we 
have 27: 100:: 75°89 : 281 cubic feet. 

I fhall now proceed from mere calculation to matter of 
fact, and attempt to prove the correétnefs of the former by 
the approximation of the latter to its refults. Let a blaft- 
furnace be fuppofed to produce.202 tons of pig-iron per week, 
= 45360 averdupoife pounds; this, divided by days, hours, 

-*minutes, and feconds, gives per day 6480 pounds, per hour 
270, per minute 44 ]b., and perfecond 525 grains. 

From this it is evident that 1b. of caft iron is produced 

in 13 13, feconds: experience has fhewn that a blaft-furnace, 

_ producing, in any of the above periods, the refpeétive quan- 
tity of metal, requires a difcharge of air per minute nearly 
equal to 1350 cubic feet; this, divided by 4,5 lb., the quan- 
tity produced per minute gives, for 1 1b. iron, 300 cubie 
feet. The quantity, by calculation, we have feen to be 281 
cubic feet—difference 19: a fum no. way confiderable when 
we refleét upon the inequality of the movements of a blowing 
machine, and when it is recollected that fome allowance 
ought alfo to be made for what air may pafs through the 
furnace undecompofed, or may be loft at the place of en- 
trance. 

From this coincidence of theory with practice, we cannot 
help admiring the rigorous principles on which the Lavoi- 
ferian fyftem is founded ; nor are we lefs pleafed to find, that, 
fmall as the operations of the chemift may be, yet they are a 

3B2°- jutt 


892 On the relative Proportions of Coals and 


jutt epitome of what takes place in the philofophy of exten- 
five manufaétories. The following table exhibits the quan- 
tity of carbon which may be ufed upon an average, with the 
relative quantity of carbonic acid formed, and air ufed :— 


In the manufacture of 1]b. — 1 ton of iron, 
The pure carbon requifite is 2°49 — 5585°44]b. 
Carbonic acid formed - 81°86 — 18336640 cub. feet 
Oxygen gasufed - - 75°89 — 169993°60 cub. feet 
Atmofpheric air employed 281°00 — 629440°00 cub. feet. 


From the foregoing particulars upon coal may be learned 
how much is dependent upon the native conftruétion of coal 
and its conftituent parts; I fhall next advert to the effects 
produced by its improper preparation. 

When coals intended for the blaft-furnace are faficiently 
charred, they ought, in point of colour, to be of a filver grey; 
their fracture will appear lamellated and porous if {plint-coals 
have been ufed; fofter coals form themfelves into branches 
ilightly curved, and, when properly prepared, are always very 
porous. I have frequently found that the better the cokes 
were charred, the more water they will abforb. Coals half 
burnt do not take up half fo much water, becaufe their frac- 
ture continues in part to be fmooth and lefs porous than 
when thoroughly burnt. 

When half-prepared cokes are introduced into the furnace, 
the metal formerly carbonated will lofe its grey fracture, and 
approach to the quality of oxygenated iron. Their prefence 
is eafily deteCted by the unufnal quantity of thick vapour 
arifing along with the flame, Befides, the water and fulphur, 
which raw coals introduce into the furnace, and which always 
impair the quantity of carbon by the various folutions ef- _ 
fected by the prefence of oxygen, hydrogen, &c. the fitnefs 
of the coal for combuftion, and the fupport of the ore, is 
much diminifhed by this fecond courfe of ignition. and dif- 
engagement of bitumen. The preflure of the incumbent ores 
alfo fraéture, and reduce the cokes into fmall pieces, which 
produce a confiderable portion of coke-duft; this is partly 
carried to the top of the furnace before the blaft: fometimes 
below it appears in immenfe quantities, ignited to whitenefs, 
and liquid as fand, Coal thus detached from the mafs, ex- 

ays pofed 


% 


“_ 


Tron-Stones ufed at the Blaft-Furnace. 373 


pofed to the ation of a compreffed current of air, is unfit for 
conveying the carbonic principle to the metal; and as it fre- 
quently belongs to the juft proportion of charcoal neceffary 
to {melt the ores, and to carbonate their iron, its lofs muft be 
felt, and the quality of iron impaired. 

When cokes of any quality are expofed. to a moift atmo- 
{fpheric, fo as to abforb water, their effects in the blaft-fur- 
nace become much reduced, and the prefence of the water 
is productive of the moft hurtful confequences in the produc- 
tion of carbonated crude iron. I have found, by repeated 
experiment, that 1 1b. of well-prepared cokes will, when laid 
in water, take up 13 ounces in the {pace of half an hour; at 
this rate, a bafket of cokes weighing 8olb. faturated with 
water, will contain 140 ounces of water, or 8]b. If the 
charge contains fix bafkets, then we fee that upwards of 
50 lb. of water is introduced regularly along with the charge, 
furnifhing an additional quantity of oxygen equal to 42+ lb., 


_ and of hydrogen equal to 7! 1b.: it frequently happens that 


the cokes contain a larger portion of water than is here fiated. 
When cokes thus furcharged are introduced in quantity into 
the blaft-furnace, the quality of the metal is not always in- 
flantaneoufly changed, and frequently thecolour and form of 
the cinder remain long without any great alteration. The con- 
tact of wetted cokes with the ore is firft feen by the great dif- 
charge of pale-blue gas, with the whiter flame at the top of 
the furnace ; next, the accumulating oxyde upon the furface 
of the pig when confolidating indicates their prefence. Iron 
thus oxygenated frequently exhibits, while fluid, that agitation 
and delicate partings peculiar to carbonated metal: the 
remelting of this iron is never attended with advantage, and 
is always unprofitable to the founder. 

From the propertics affigned to pit-coal in this and in 
former papers, the following faéts may be deduced :—That 
charcoal ig the bafis of the manufaéture of crude iron; that 
its proper application produces the moft valuable qualities of 
pig-iron; that, by diminifhing its relative proportion, or con- 
taminating its quality by heterogeneous mixtures, the value 
and fufibility of the metal is loft; but that, by a proper in- 

. creafe, 


374 On the relative Proportions of Coals and 


ereafe, and always in proportion to this increafe will the 
fufibility and value of the iron be mended.- From the whole 
an important leffon may be learned of the pernicious effeéts 
of water in the furnace, and how abfolutely neceffary it is to 
prepare the cokes without ufing water, either to damp the 
fires, as in the ufual mode, or to cool the cinders obtained 
from the tar kilns, to prevent their confuming in the open 
air: in all this hurtful operation confiderable quantities of 
water become fixed in the cokes, which require a very great 
degree of heat to expel. 


THE preparation of iron-ftone has already been fully at- 
tended to, and the phenomena which it exhibits under every 
ftage minutely defcribed. In confequence of various expe- 
riments we are authorifed to draw the following conclufions : 
That when pure calcareous iron-ftone is ufed, it admits of hay- 
ing the local quantity of cokes diminithed ; that argillaceous 
requires a larger portion than the calcareous genus; and that 
filiceous iron-fione requires a greater proportion of fuel than 
any variety of the former genera. ° We have alfo feen that 
fafibility, either conneéed with ftrength or otherwife, is de- 


rived from the mixture of the ores; and that exceflive brittle-. 


nefs, intimately conneéted with infufibility, is alfo derived 
from the fame fource. From a review of thefe faéts, we are 
forcibly impreffed with the importance of combining the pre- 
pared iron-fiones with proportions of fuel fuited to their va- 
ious natures, in order.to produce all the varieties of crude 
iron with the greateft poflible ceconomy. Contemplating 
farther the fame fubject, it is eafy to be conceived that a 
want of knowledge of the component parts of iron-ftones, 
and the effects which individually they produce, muft lead 
to great uncertainty of operation in the fmelting procefs, 
wherein the beautiful ceconomy of nature, and even real 
property, will be often unprofitably facrificed to precedent. 
Befides the above caufes of alteration, dependent upon 
mixtures of the ‘earths, the exiftence of oxygen in various 
quantitics in the ores ought never to, be overlooked in pro- 


portioning the cokes to the iron-ftone. “This powerful agent, 


whole 


k Tron=Stones ufed at the Blafi-Furnace. 393 


whofe form and fubfiance conftantly eludes our yifion ;' whofe 
exiftence is only afcertained by the wonderful changes pro+ 
duced by its various combinations with the iron; and whofe 
prefence in the fame iron-ftone, in various quantities, may: 
produce fuch variety of refult as to charaéerife the ores, as 
centaining good or bad iron, furely forms the moft intereft- 
img mixture which ores or iron-ftones poflefs, It will be a 
momentous epoch in the manufacture of iron when the ex- 
iftence of fuch a principle {hall be fully admitted by the ma- 
nufacturer, and its agency, from certain vifible effects pre- 
duced, adopted to explain its accompanying phenomena, 
Till that period he will not perceive the utility of afcertain- 
ing the quantity of oxygen, and_devifing ceconomical me- 
thods of taking it from the ore. An attention to this pow- 
erful principle can alone root out thofe prejudices fo inimical 
to the real interefts of the manufacturer, and which feem to 
glance at Nature, as having improvidently,, combined, her 
moft ufeful metal with mixtures which could refift the inge- 
nuity of man, or fet his comprehenfive intellect at defiance, 
In the progrefs of this great inquiry, is it not poflible that the 
prefent expenfive exertions may in part be fuperfeded? Is it 
not poflible, that, by laymg open the fources of \informa- 
tion to individuals at large, a greater mafs of intellect may 
engage in, the praétice of this art? While the prefent ex- 
tenfive and lofty buildings are neceflary, the bufinefs is en- 
tirely confined in the hands of men of great capital: the ex- 
tent of their manufactures require that alarge tract of coun- 


‘try be devoted to their fupply ; a natural confequence is, that 


innumerable fimall tracts of land are overlooked, or held un- 
worthy of notice, merely becaufe they cannot, in a period 
neceflary to clear a great capital and infure a fortune, affordé 
the neceffary fupply. of materials. Such fituations, accord- 
ing to the prefent fiate of the iron bufinefs, muft remain uns 
explored. Should, however, a defire for truth once gain foot- 


_ing in the manufaétories of iron, and fhould this natural 
-impulfe of the unprejudiced mind keep pace with other 


branches of intellectual information, we may not defpair of 
feeing many imperfections removed, which were the unavoid- 
able confequence of the period of their creation. ; 

In 


375 On the relative Proportions of Coals and 


In the application of iron-ftone ‘in the blaft-furnace, the 
following particulars ought rigoroufly to be attended to :— 

1. Their mixtures, whether clay, lime, or filex: their 
relative proportions to each other, judging according to the 
rules formerly laid down; which of them may admit of a di- 
minution of fuel ; which of them will afford the quality of 
iron at the time requifite; and which of them will be moft 
likely, by a judicious arrangement, to give the greateft pro- 
duce of metal, united with value and ceconomy. Iron-ftones, 
united with large portions of filex, have already been ftated 
to require a greater proportion of fuel to carbonate their metal 
than the other genera. When ballaft or forge-pigs are 
wanted, it ftands to reafon that filiceous iron-ftones ought 
to be ufed; not that they contain a greater quantity of iron, 
but becaufe they form a fubftitute for the other kinds, which 
may be more advantageoufly fmelted for the produétion of 
more valuable qualities. 

2. Thequantity of metal which each individual iron-fionemay 
contain, is another object of confideration. Befides the pro- 
portion of mixtures, which chiefly contribute to the fufibility 
of iron-ftones, a fecond degree of fufibility is dependent upon 
the richnefs of the ore in iron: this is fo obvious in the ufe 
of the Cumberland and Lancathire ores, that the ‘confe- 
quences of their introduction will be perceived, by the change 
of the fcoria and metal, in half the time that change would 
be effected by ordinary iron-ftones. It has been frequently 
noticed, that crude iron contained pure carbon in proportion 
to its fufibility ; then the more fufible, or fupercarbonated 
qualities, muft take up, comparatively, a confiderable portion 
of the carbonaceous principle from the fuel. From this refults 
a ftriking confequence, that the quantity of fuel fhould, over 
and above its relation to the mixtures, bear a juft proportion 
to the quantity of iron in the ftone: for example, let the 
weight per charge of fuel at a blaft-furnace be 400lb., and 
let this be fuppofed fufficiently to fufe and carbonate the iron 
contained in 360 |b. of iron-ftone; let the quantity of metal 
be fuppofed 35 per cent. then the produce will be 126 lb. 
Should a change take place, and iron-ftone richer in iron be 
applied, though the fame by weight, and fhould this iron- 

ftone 


Tron-Stones ufed at the Bla/t- Furnace. 377 


ftone yield of torrefied ftone 45 per cent. its produce will be 
162tb. or 4olb. more than the former. “As there exifts no 
greater proportion of carbon in the furnace, it is evident 
that the exifting quantity, being diftributed over nearly — 
1-3d of more metal, muft therefore be in more {paring quan- 
tity in the whole, and the value of the metal confequently 
reduced. 

3. The weight of oxygen contained in iron-ftones is the 
next obje&t of ferious confideration. I have already fhewn, 
from experiment, that our iron-ftones naturally contain from 
9 to 14 per cent. of oxygen, which remains after torrefaction 5 
it, has alfo been fhewn, that this quantity of hurtful mixture 
may eafily be doubled by over-roafting or under-roafting the 
ftone; and that the bad effects entailed are in the ratio of its 
combination with the iron. From a review of the faéts ad- 
duced on this fubject in various parts of my papers, its agéncy ° 
and effects will eafily be credited by men of feience ; its pro- 
perty of conftituting the acidifying bafe of all the acids rea- 
dily explains the unalienable confequence of its prefence with 
acidifiable bafes. The effects are ftill more pernicious when 
the oxygen is furnifhed by the decompofition of water in 
raw iron-ftone; the hydrogen in this cafe fet free, alfo feizes 
a portion of the carbon; and thefe abftractions, united to that 
produced by the native portion of oxygen in the ftone, form 
an aggregate which frequently reduces the value of iron 40 
per cent. So long as the principles of feience are overlooked 
in the manipulations of the foundry and forge, the exiftence 
of fuch agents will be treated as chimeras of the philofopher 
and chemift, and the effeéts hourly produced: by them in- 
duftrioufly attributed to caufes which in point of unity or 
confiftency will not bear the flizhteft touch of inveltiga- 
tion. 


Vou. V. 3C XY A new 


Egy 4 
ey ; paces 
XI. A new Theory, pointing out the Situation of the Mag- 
netic Poles, and a Method of difcovering the Longitude, 
By P.R. Nucent, E/g. formerly Surveyor-General of 
Lands for the Ifland of Cape Breton, Commynicated by 
the Author, 


Tus feveral interefting and important voyages, under- 
taken by order of his prefent Majefty, for making difcoveries 
highly beneficial to mankind, particularly in what relates to 
geography and navigation ; andthe great defire and intention 
of deriving every poffible benefit from the many obfervations 
which fuch extended voyages were defigned to offer ample 
room and opportunity for making, became objects of pecu- 
Jiar concern and confequence. In addition, therefore, to the 
undoubted and acknowledged abilities of the refpective com- 
manders and officers appointed to fuch defignations, the 
Commiffioners of the Board of Longitude thought fit to ap- 
point, for every voyage, one or more perfons on wuhol fcien- 
tific ability, fidelity, and diligence in affifting to make the 
refpective obfervations, they could alfo reft fatisfieds Thefe 
gentlemen were therefore furnifhed with the completeft in- 
ftruments whjch the moft ferupulous care, intention, and 
circumfpection, together with a total difregard to expence, 
could be found to procure. Their report and teftimony is 
therefore conclufive proof of the perfection or imperfeétion 
of the feveral infiruments they had with them; their report 
of the azimuth compafs, and dipping-needle or compats, is 
as follows :— 


ar the Azimuth Compafs. 


The late ingenious and accurate the Hon, Captain Phipps, 
afterwards rae Mui: grave, in his account of his Voyage to- 
wards the North Pale, p- 108, remarks as follows nae The 
variation of the compafs, always an interefling object to na- 

vigators and philofophers, became peculiarly ‘fo in this voy- 
age, from the near approach to the Pole: many of the theo- 
ries that had been propofed on this fubje& were to be brought 
to the teft of obfervations made in high latitudes, from which 
alone 


Theory of the Situation of the Magnetic Poles, &c. 379 
alone their fallacy or utility could be difeovered; they of courfe 
engaged much of my attention, and gave me the fulleft op- 
portunity of exper ieheing; with regret, the many imperfec- 
tions of what is called the azimuth compafs... This inftru- 
ment, though fufficiently accurate to enable us to obferve 
the variation fo as to enable us to fteer the fhip without any 
material error, with the precaution of always ufing the fame 
compafs by which it is taken, is far from being of fuch 
aconftru€lion as to give the variation with thiat degree of 
precifion which fhould attend experiments on which a theory 
is to be founded, or by which it is to be tried. The obferva- 
tions taken in this. voyage will fully evince this by their great, 


variations from one another in {hort intervals of time; nor 


is this difagreement of fucceffive obferyations peculiar to high 
Jatitudes, and to be attributed to a near approach to the Pole, 
as I found it take place even upon the Englifh coaft.” 

Mr. Wales, F.R.S. Mafter of the Royal Mathematical 
School in Chrift’s Hofpital, Secretary to the Board of Lon» 
gitude; &c. in page 49 of the IntroduGion to the Original 
Aftronomical Obfervations ntade in the Courfe of a Voyage 
towards the South Pole, and round the World, in his Maje- 
fty’s fhips the Refolution and Adventure, in 1772, 17735 
1774, and 1775, by himfelf and Mr. William Bayley, now 
Matter of the Royal Academy at Portfmouth, pubbthes by 
order of the Board of Longitude, fays : 

<¢ J cannot pafs over this article without making a tema 
or two on the irregularities which we found in the obferva~ 
tions made with thefe. inftruments in the Channel of Eng- 
land: the extremes of the obferved variations were from 
193 to 25; and all the way from England to the Cape of 
Good Hope 1 frequently obferved differences nearly as great 
without being any way able to account for them, the dif- 
ference in fiasiatiors being. by no means fufficient. Thefe 
irregularities continued after leaving the Cape,” 7. ¢. they 
continued throughout the voyoge. Bat thefe irregularities are 
trifling compared with thofe 


Of the Dipping Needles, or Compafs. 
Thefe inftraments were fo imperfect in principle, and thé 
obferyations made with them fo uncertain, that, excepting 
3C a the 


x 


386. Theory of t*e Situation of the Magnetic Poles, 


the obfervations of the magnetic inclination, made at anchor 
or on fhore, (and even thefe, as any one may perceive, were 
far from being certain,) no manner of ufeful certitude or 
judgment could arife from them. Mr. Wales, in his de- 
{cription of the dipping needle here fpoken of, and made by 
Mr. Naime agreeable to a plan of the Rev. Mr. Mitchell, 
F.R.S. obferves, in page 50 of the Introduction aforefaid : 

‘© The principal defects in this conftruction are, the diffi- 
culty in placing the wires which carry the two laft men- 
tioned balls in the proper plane, and the total impoffibility 
of knowing when they are fo: moreover, it is very poffible, 
and undoubtedly often happens, that the axis of the needle 
and its two poles do not lie in the fame plane, in which cafe 
another difficulty will arife in adjufting the needle to great 
exactnefs.”” And in page 15 of the Obfervations themfelves, 
Mr. Wales remarks as follows : 

¢ The dipping needle which we took afhore at this place 
(the Cape of Good Hope) was fo much out of balance, and 
fo difficult to get in again, that notwithftanding we both of . 
us (Mr. Wales and Mr. Bayley) fpent all the leifure time we 
had from other obfervations, we did not get it perfe@tly ad- 
jufted before we went away, and of courfe were not able to 
get any obfervations of this kind at this time.” 

Mr. Bayley, in page 217 of the Original Obfervations 
made in the courfe of a voyage to the Northern Pacific 
Ocean, for the difcovery of & north-eaft or north-weft paf- 
fage, in his Majefty’s fhips the Refolution and Difcovery, in 
the years 1776, 1777, 1778, 1779, and 1780, after, as appears, 
much precaution on obferving with, and changing the poles 
of the dipping needle, &c. fays: On the 28th July is men- 
tioned an accident happening to the dipping needle: “ the 
poles were not then changed, as the obfervations afterwards 
appeared regular; neither were the poles changed on receiving 
#t on board, as it was faid to be well balanced: but the not 
doing it at either of thefe times was a great overfight, as we de 
not know the error of the dips with the marked end north, and 
dipping in any obfervations before to-day, and therefore can- 
not correct them according to Mr. Cavendith’s direCtions. 
If we fuppofe the fame error from the firft as on to-day, (the 

mean 


and a Method of difcovering the Longitude. 38t 


mean dip with the marked end north, exceeding the mean 
dip with the marked end fouth by 8° 8’), then are the mean | 


dips from the beginning to be diminifhed by a or 244 X% 


cofine of the dips. If, again, we fuppofe no error on receiv- 
ing it, nor from the above accident, the mean dips to this 


day will be leffened by at or 122 X cofine of the dip.” 


What error or difference arofe between the extreme of the 
obferyed dips with the marked end north, and thofe with the 
marked end fouth, are no where fet down; they muft, how- 
ever, undoubtedly have been greater, and in all likelihood 
inuch greater than 8° 8’, feeing the mean refult of the whole, 
fmall and great, gave 8° 8’, The obfervations made by Lord 
Mulgrave are of the like nature and uncertainty. 

The whole of thefe inftruments were therefore totally in- 
adequate to the correct and ufeful purpofes of navigation, or 
indeed to any corre€tly ufeful purpofe whatever: they were 
however, as before obferved, the very beft that could be ob- 
tained; and in the making of which no expence whatever 
on the part of the Board of Longitude, nor pains on the part 
of thofe who made them, were wanting to render them as 
perfec as poffible, and fych as fhould anfwer the purpofes 
for which they were defigned; nor do I entertain any doubt 
they were as much fo as the nature of their conftruction could 
poffibly admit of. : 

My purfuits in hfe having been confiderably conneéted 
with objects of this kind, my own experience, corrobo- 
rated by the above and like teftimonies, together with the 
continual neceffity, which arofe from time to time, of in- 
creafing the magnetic orbit fo as to correfpond to the increafe 
of the variation (on the fuppofition that the true dip and va- 
riation might be accounted for and prediéted,) by means of 
moveable magnetic poles *, led me into endeavours to invef- 

tigate 

* William Whifton, M. A. in the 8th page of an hiftorical preface to 
2 p»mphict of his, entitled, « The Longitude and Latitude found by the 
Iuciinatory or Dipping Needle,” gives us the brief hhiftory of*all'theories 
then publifhed, in chefe words, {peaking of the magnetic poles and theories: 

« However, this -notion in general of moveable magnetic poles has al- 

Ways 


382  «=Theory-of the Situation of the Magnetic Poles, 


tigate fome theory more conformable to the laws of Nature*; 
and which would reconcile the continual difagreement be- 
tween men of fcience on this fubject: and this defire alfo of 
neceffity led me into endeavours to form more perfect nau- 
tical inftruments, fo without more accurate obfervations no 
effential utility whatever could arife to navigation from any 
kind of theory however perfect. To detail the train of reafon- 


. ‘ways feemed fo probable, or rather neceffary, ever fince the variation has 
been itfelf found to vary, and this after a certain regular manner; allo, 
that Mr. Phillips before Mr. Bond afferted the fame, and ftated the revo- 
Tution to be in 370 years; and after all, our learned Dr. Halley, who has 
far outdone every body upon this fubjeét, has determined it to be fo, only 
he has thonght himfelf obliged to add the hypothefis of two other fixed 
poles; and from the joint efleéts of all four poles, and from thofe only, 
has he been able to bring this variation of the variation to fome kind of 
fy{tem agreeable to the obfervaticns. He has alfo been obliged to lengthen 
the period of the moveable poles’ revolution; and as Mr. Bond had en- 
Jarged Mr. Phillips’s number fiom 370 years to 60d, fo has Dr “Halley 
enlarged the fame farther, ftom 690 to 7e0 years;” and Mr. Whifton, in 
page 58 of the pamphlet itfelf, flates the revolution of Dr. Halley’s inner 
nucleus, or north magnetic pole, to be in 1920 years, which, he obferves, 
is much flower than that of Mr. Phillips, Mr. Bond, or Dr. Halley. 

Since Whifton’s time, thofe who attempted the magnetic theories are : 
the celebrated Euler, who, as ail others have hitherto done, fuppofes 
that the magnetic poles move; Mr. Lorimer, Mr. Churchman, Mr. 
Walker, &c.; but of all thefe, Mr. Churchman is the only perfon that 
determines their revolution, which he ftates to be, the northernmoft in 
1096 years, and the fouthernmoft in 2289 years. 

I fhall forward, for a future number of the Philofophical Magazine, a 
more full account of the theories that have hitherto prevailed, in which f 
Shall enter more fully, than my prefent mits will allow, into the truth of 
my new theory, and of the method by which I have been enabled to prove 
the fallacy of the former. In the mean time any perfon, even by roughly 
perufing the obfervation of latitudes, longitudes, and dips, made on the 
north-weft coaft of America, and comparing them with that at Londen, and 
alfo with thofe made off the eaft coaft of South America and in the Chi-+ 
nefe feas, will foon be enabled to afcertain,; fu fficiently near for the purpo!e 
of remaining fatisfied, that the fituatiow of the magnetic poles is as de- 
feribed: my determinations are, however, drawn from a multitude of cal- 
culations, and the refult compared with all the magnetic dips and varia- 
tions (taken in all the different places on fhore) I could procure. 

_ ™ Vaccount for the change of the magnetic variation by original mag’ 
nelic meridians and a magnetic annulus. Nz 


ing 


‘and a Method of difcovering the Longitude. 383 
ing and confequent inveftigation I went through, would be 
unneceflary here. The refult, which I have long fince ex- 
plained to many individuals, I now, in as brief a manner as 
the fubject will admit of, lay before the public, not doubting 
that an obje&, which actually tends to the enlargement and 
perfection of fcience, and, in my opinion, to the benefit of 
navigation, will find favourable reception, inveftigation, and 
experiment. 


Method of difcovering the Longitude, the Magnetic Inclina- 
tion-and Latitude of the Ship beng given: 


Prope the Firft, being the Tazory. 


To determine the Latitude and Longitude of the Magnetic 
Poles, and, in confequence, for the purpofe of difcovering 
the Longitude, to afcertain a Firft Meridian, 


Let N (Plate VIII.) reprefent the north pole of the earth, 
M the magnetic north pole, S Smeerenberg harbour in Spitf- 
bergen, and L London: alfo, let arches of great circles be 
drawn from London to the north magnetic pole, to the north 
pole of the earth, and to Smeerenberg, and alfo from Smeer- 
enberg to the north magnetic pole. There will thus become 
formed three fpherical triangles, which are refolved as fol- 
lows :— 

ift, In the triangle NLS are given the fides NL and 
NS, being the co-latitudes of London and Smeerenberg, and 
the included angle LN S being their difference of longitude, 
to determine the angle of pofition N LS and the third fide LS, 

ad, In the triangle LSM are given the three fides LS, 
(juft found) LM and SM (LM and SM being the magnetic 
polar diftances correfponding to the correct dips at London 
and Smeerenberg), to determine the angle MLS, from 
which fubtracting the angle NLS lately found, there re- 
mains the angle of pofition NLM, 

Laftly, In the triangle MLN are now given the fides 
LM and LN, and the included angle MLN, to find the 
angle LN M, the longitude of the north magnetic pole (and 


the meridian of the earth pafling through the magnetic poles 


and 


384 Theory of the Situation of the Magnetic Poles, 


and poles of the earth,) from the meridian of London, and 
the fide MN the diftance of the magnetic pole from the pole 
of the earth. 

The place of the magnetic poles being thus obtained, the 
queftion next divides itfelf into two points of view, namely, 
Whether the magnetic poles or points thus determined are 
ftationary or otherwife? the folution of which depends on 
obfervation and philofophic inference. From obferyation it 
is remarked, in page 121 of the late Lord Mulgrave’s Account 
of his Voyage towards the North Pole, that— 

«© There is no reafon at prefent to fuppofe that, the dip is 
liable to any variation in the fame place at different periods 
of time. It having been obferved at London by Norman, 
who firft difcovered it in 3592, to be 71°.50’, and by Mr. 
Nairne, in 1772, about 72°: the difference between thefe ob- 
fervations, taken at fuch diftant periods of time, is fmaller 
than that found between feveral of Mr. Nairne’s obfervations 
compared with each other; and therefore we have no reafon 
to conclude that the dip has altered fince Norman’s time. 
The care with which his inftrument was conftructed, and 
his obfervations made, leave us no room to doubt of their 
accuracy.” 

Again, Mr. Cavallo, in his Treatife on Magnetifm, p. 65, 
remarks, (fpeaking of the dip,) ‘* Its alteration in the fame 
place.at different times is very fmall; thus in London, about 
the year 1576, the north pole of the dipping needle ftood 71.50 
below the horizon, and in the year 1775 it ftood at 72. 03: the 
alteration of the inclination in fo many years amounting to 
Jefs than a quarter of a degree, which may be attributed to 
the error of the inftruments, fince, as will appear in the fe- 
quel, thofe infiruaments are far from having attained to any 
degree of perfection even in the prefent age.”’ : 

Now, from philofophic inference it will naturally follow; 
that if the inclination of the magnetic needle at different pe- 
riods of time at any one place remain conftant, the magnetic 
poles are ftationary; and if the magnetic poles are fiationary, 
(as appears clearly evident from above,) the meridian thus dif- 
covered is the Fir/f (or only) Meridian from which the lon- 

gituds 
Z 


and a Method of difcovering the Longitude: 385 
gitude ought to be counted; I have always ufed it as fuch, 
and obtained the moft fatisfactory refults. 


Proxpiem the Second, being the Pracriceé. 
To determine the Longitude univerfally, 


Here are always given the fhip’s polar diflance, the mag- 
netic polar diftance, and the magnetic co-latitude, being 


_ three fides of a fpherical triangle, to determine the angle at 


the pole of the earth oppofite the magnetic co-latitude, being 
at all times and places the longitude of the hip eaft or nak 
(as the cafe may be) from the meridian aforefaid. 

N.B. The magnetic co-latitude is the diflance of the fhip 
from the neareft magnetic pole; the fhip’s polar diftance is 
the diftance of the hip from the pole of the earth next ad- 
joining the faid magnetic pole ; ; the polar diftance is the dif- 
tance between either magnetic pole and the pole of the earth 
neareft tHereto: moreover, the longitude thus obtained can 
never exceed 180. It may, braves, be eafily reduced as to 
that eftimated from any affumed firft meridian. Likewife the 
point M, thus affumed as the magnetic pole, may, to prevent 
perplexity, be better underftood as being that point on the 
furface of the globe at which the dipping needle ftands at 
right angles to the plane of the horizon, without regarding 
whether the magnetic poles themfelves are under, at, or aboye 
the furface of the earth. 

The method of obtaining and eftablifhing (from obfervation 
alone) certain data for inveftigating or corroborating perfect 
tables of magnetic latitude and co-latitude, appears (from the 


preceding theory) obvious, being, by carefully making different 


dips of the magnetic needle along the meridian aforefaid, and 
carefully obferving the refpeétive latitudes at which thofe dips 
are taken, and for greater certainty (if thought needful) con- 
tinuing tliem, as far as poffible, into both hemi/pheres; though 
it will alfo be perceived they may be inveftigated by obferying 
different dips, along any other great circle, pafling through 
the magnetic poles, or having determined the precife latitude 
and longitude of the magnetic poles. Correét tables may alfo 
be deduced from correét dips at various places; however, the 


VoL. VY. 2D firkt 


c 


386 = Theory of the Situation of the Magnetic Poles, 


firft method is not only the moft eafy, but on many accounts 
the moft preferable ; and for this purpofe the correét dips of 
the magnetic needle, taken at the following places, (regard 
alfo being had to determine their correé latitudes and lon- 
gitudes, particularly the former, except near the magnetic 
poles, where it is neceflary to corre&tly determine both,) will 
be found fufficient, namely, at the Falkland Iflands, Buenos 
Ayres, Oroonoque, Trinidad, Barbadoes, Saint Luke, Mar- 
tinique, Guadaloupe, Antigua, Saint Martin’s, Bermudas, the 
Atlantic Ocean, in or near the fame longitude up to and near 
the Ifle of Sables, at the Hland of Cape Breton, the fouth 
fide of the river Sat Lawrence in the longitude aforefaid ; 
then going round to the north-eaft fhore of the Labrador 
Coaft, and obferving thereon at Davis’s Inlet, and fo on up 
to the northward under the meridian aforefaid, up to and 
into Baffin’s Bay, and there carefully determining the lati- 
tude and longitude of the north magnetic pole ; or firft going 
into Baffin’s Bay, and afterwards proceeding to the fouth- 
ward. 

Next, by carefully obferving the nragnetic melination along 
the oppofite meridian in Ruffia, China, the Chinefe Seas, 
Indian Ocean, &c.; as at the mouth of the Leno, at Olikf- 
minfkoi, at Nutfchink or Albazin, at Pekin, Nankin, Nim- 
po, Formofa, the Philippine Ifles, Gindano, Celebes, Flores, 
the north and fouth fide of New Holland, and fo continuing 
to, obferve along the Indian Ocean, in or near the meridian 
aforefaid, up towards the fouth pole of the earth, until the 
place of the fouth magnetic pole be carefully determined, 
i. e. whatever pole may be firft convenient to determine, 
The number of places herein fet forth are mentioned in order 
ihat navigators and others, as opportunity may offer, may 
know where and how to make the advantageous obfervations 
herein alluded to. writ 

It may alfo be proper to add, that hitherto the places’ of 
the magnetic poles have always been attempted to be found 
by means of the magnetic variation ; a method whereby the 
moft able mathematicians have been continually led aftray, 
for, as the magnetic variation is continually changing, their 

conclufions 


SS 


andi Method of difcovering the Loxgitude. 38 


conclufions were rendered as uncertain as the variation itfelf, 
of which (it had fo happened from the method they purfued) 
they knew little more than that it did change. Had the 
prefent theory occurred to them, it would have received 
chearful and favourable countenance and encouragement, 
and it and its utility been foon and effectually eftablithed. 

Had the indefatigable and famous Dr. Halley in parti- 
cular known shaveus when he undertook two voyages (long 
afier the inclination of the magnetic needle was difco- 
vered, nanxly, in 1698 and 1699) for the exprefs purpofe 
of endeavouring to form a magnetic theory by means of a 
multitude of obfervations of the magnetic variation, as a pre- 
paratory ftep, and in order to determine the longitude there- 
by, or, as his inftructions run, “ to feek, by obfervation, the 
rule of the variation of the compafs ;”’? the obfervations of 
magnetic dip here recommended, and which he would have 
made at leaft along the weftern line before pointed out, toge- 
ther with’ the obfervations of the variation of the compat: 
which he did obferve, in all likelihood, if made with inftru- 
ments capable of affording the requifite accuracy, would have 
foon fuggefted, to his. penetrating and fruitful genius, the 
correct object of his refearch. 

It may be farther proper to remark, that the obfervations 
of the magnetic inclination herein ftated, and made at Lon- 
don, do of themfelyes alone eftablifh another important 
conclufion, likewife quite different from the general opinion 
of the Learned, which fuppofes that the magnetic variation 
affects (z. e. increafes or diminifhes) the magnetic inclina- 
tion; for, from the time in which the magnetic inclination 
was firft obferved at London to the prefent time, the varia- 
tion has fhifted upwards of 36° without affecting the inclin. 
ation; and therefore, after knowing the refult of fo very great 
a change in the magnetic variation without having affected 
the inclination, there can be no reafon to conclude that it 
can in any refpeét be affected thereby: a circumftance that 


renders the theory here pointed out {till more fimple and 


beautiful. 
Thus, by new and interefting application and teftimony 
of unerring fcience, praclical obfervation, and fair conclufion, 
3D 3 I have, 


388 = Theory of the Situation of the Mugnetic Poles, 

I have, I flatter myfelf, cleared the magnetic theory of the 
abftrufe and embarraffing confiderations which have hitherto 
bewildered it, and thereby laid the foundation of a moft 
fimple, general, and ufeful method of determining a fhip’s 
correét place at fea, without any regard to the fun, moon, or 
ftars, to good or bad weather, to the time of the day, the day 
itfelf, months, years, feafons, or centuries, except fo far’as 
may be faid to regard the magnetic inclination, which muft 
always be known from obfervation; as alfo the latitude of 
the fhip, which mutft likewife be known, either from obferv~ 
ation, or dead reckoning. 

- JT would not have it aeiderithods however, that I mean to 
decry the ufe of lunar obfervations or chronometers. Far 
otherwife: I have devoted great application to the ftudy of the 
lunar (and other) aftronomy; and herein I am happy to add, 
IT have fucceeded to an accuracy and concifenefs of equa- 
tions and calculations far furpaffing Mr. Mayer’s, or any 
lunar tables yet offered to the public. But herein, notwith- 
ftanding the high efteem and veneration in which the great 
genius and labours of Euler, and the merits of Mr. Mayer 
muft ever be held by men of fcience, I found it neceffary to 
reject, for reafons which I fhall hereafter tranfmit for infer- 
tion in the Philofophical Magazine, the fuppofition that the 
motion of the fun or earth, according to Mr. Euler, and of 
‘the moon according to Mr. Mayer, are different now to what 
they formerly were. I am alfo the original inventor, and for 
which I have, for upwards of feven years, had a patent, of a 
double fextant for making lunar obfervations to the right and 
Jeft. I have alfo invented a metal quadrant, by which, with 
fore-adjuftments and obfervation, the diftance of the moon 
can be meafured from the fun or other object, from one 
Jimit or extreme point of the horizon to the other, 

From the multitude of lunar places which T have calcu- 
Jated from my tables, I am perfuaded they are fuch as fhall 
not, even at the equator, produce a mean error of five, nor 
an extreme error of fifteen miles in longitude. The firft of © 
the infiruments here fpoken of (a double fextant) meafures 
with convenience, without inverting the inftrument, the 
fimple limits of a fextant on either fide the fun or a fixed far: 

fe) to 


and a Method of difcovering the Longitude. 389 


to the other there can be no limits, for it meafures 180 dee 
grees on either fide. Not fatisfied with doing thus much, in 
order to avoid the inconvenience, trouble, and inaccuracy 
arifing from the ufe of large volumes of charts of {pherical 
triangles, and of tables for reducing obferved lunar diftances 
to true, I contrived an infirument, for which, as well as fe- 
veral fuperior furveying and other inftruments, I have alfo 
gota patent. This inftrument, which I have denominated 
a fuit of circles of calculation, performs this operation with 
eafe, accuracy, and expedition. It alfo determines the true 
Jatitude, without knowing the latitude by account, either by 
double altitudes and the time between, by double altitudes 
and the difference of magnetic azimuths, (which my in- 
ftruments will correétly give,) or by fimply having the alti- 
tude of two known fixed ftars, It determines the time of the 
day, &c. &c. In a word, it refolves all manner of {pherical 
triangles or fpherical trapezia, &c. The refolution of the 
few of thefe that conftitute the effentials of nautical aftro- 
nomy and geography, becomes by this means obvious, eafy, 
and pleafant; whereas the under{tanding, or even the appear- 
ance of the previous burthen of requifites, creates, as is well , 
known, a great if not infuperable obftacle to the generality 
of otherwife well-informed feamen. 

Having thus, I truft, explained my regard and efteem for 
the lunar obfervations and chronometers, all I would have 
underftood of the method of difcovering the longitude by the 
dip is, that it is eafily underftood by the moft ordinary capa- 
city; that to others, in every inftance, it becomes an auxi- 
liary or corroborating proof, and, in the time of greateft ne- 
ceffity and peril, a moft eftimable fubflitute; not requiring, 
in this cafe, any calculatiomwhatever. Thus, from the pre- 
ceding theory, the dip in all places remaining the fame, 
the navigator, being perhaps feveral days without feeing fun, 
moon, or ftars, fo as to make any ufe of either towards de- 
termining his longitude, has this benefit left him, that he 
¢an, at any moment of the day, in which the extremity of 
the horizon can be feen, determine his correét dip, and 
therefore his vicinity towards the land he wifhes to make or 
avoid; where otherwife he might ejther be caft away, or, under 
the 


ago Theory of the Siiuation of the Mapneitc Poles, 


the fuppofition that he was near thereto, keep either lying-to, 
or Rraining his fhip in endeavouring to get no farther to lee- 
ward, when at the fame time he might be an hundred miles 
er more from fhere, and fo lofe the very wind he wanted ; 
after which, fhould contrary winds affail him, the injury alfo 
becomes obvious. 


« 
Zo clear apparent or obferycd Lunar Diflances from the Effects 
_ of Refraétion and Parallax by the Swit of the Circles. 


Set the vernier on the firft meridian, carrying the circle or 
femicircle of pofition to the apparent altitude of the fun’s 
eentre, or that of the ftar; the vernier on the moveable meri- 
dian to the apparent altitude of the moon’s centre; and the 
yernier on the circle or femicircle of pefition to the apparent 
diftance of the fun and moon’s centres, or of the centre of 
the moon and fixed ftar. Let thefe form a {pherical triangle; - 
fo fhall the number of degrees, minutes, and feconds on the 
eguator, comprehended between the firft and moveable me- 
ridian, fhew the angle (or difference of azimuths) at the ver- 
tex, which angle is common to the apparent and true tri- 
angle. Keeping faft, therefore, the faid meridians by means 
of the equator, fet the vernier on the firft meridian to the true 
altitude of the fun or fiar’s centre, and the vernier on the 
moveable meridian to the true altitude of the moon’s centre; 
then fee what number of degrees, minutes, and feconds of 
the circle or -femicircle of pofition or diftance are contained 
between them, for that is the true diftance. 


: Port/mouth, Dec. 13, 1795: 
WE certify, that, in our opinion, a compafs and fextant 
invented by Mr. Nugent merit an expeditious and accurate 
inveftigation and trial. ¢ 
(Signed) TT, Packenuam, Le Jujfie. 
J. Craunston, Bellerophon, 
E, Gowen, Triumph. 
W. Domert, Royal George. 
R, Bowen, Terp/ichore. 


The foregoing certificate was given to me, unfolicited, for 
the purpofe of being tranfmitted to the Lords Commiffioners 
| of 


sand a Method of difcovering the Longitude. 307. 


éf the Admiralty, in order to procure their Lordfhips order 
to haye'the merits and efficacy of my inventions and inftru- 
ments officially examined into and reported upon. As to the 
inftruments, they were on the fame day applied for, throug: 
Commiffioner Marfh, to the Navy Office, by the above gen- 
tlemen. 

' The moft fpeedy and leaft expenfive method of afcertaining 
the précife fituation of the north magnetic pole, the fouthern 
being oppofite thereto, appears to Be, by engaging one of the 
Davis’s Strait whalers to proceed into Baflin’s Bay, with e 
proper perfon duly qualified, to make the ‘neceffary aftrono- 
mical and magnetic obfervations ; or rather,. by difpatching 
for this purpofe a frigate or other veffel in the king’s fervice 
¢«mployed on the Newfoundland ‘ftation. Pity it was, indeed, 
that the Board cf Longitude had not Known of this methed, 
and of the reafons that render all navigation into the South 
Sea, by any paflage to the eaftward of Greenland, totally im- 
practicable.’ The Hon. Captain Phipps’s deftination would 
in that cafe -have been to proceed into Baffin’s Bay, where, 
had he alfo pofleffed the angular and magnetic inftruments 
herein alluded to, he would have affuredly afcertamed one 
great object of his voyage, namely, the detérmining the fal- 
lacy or utility of all previous theories, and bringing them to 
the teft of experiment; a te(t which would have caufed the 
whole to have vanifhed,-and none other would have remained 
but that I. have already pointed out. Nor do fF entertain 
much doubt that, by attending to circumftances, which 
might eafily be pointed out, Captain Phipps would have alfa 
accomplifhed a paflage into the South Sea. 

The principles of the whole of my nautical magnetic in- 
ftruments (except a variation frame for converting ali fteering 
into variation compaffes) is the application of a quadrant, 
fextant, or double fextant, (fitted for this purpofe,) to the ver= 
tical magnetic axis of the horizontal needle for determining 
the variation, and to the lateral mag-etic inclinatory axis of 
the dipping needle for determining,the dip. Thefe needles 
are alfo differently fufpended from others: the dipping nee- 
dle, for example, is always at liberty to refort.to, and remain, 
eyo'ls ON al 


492 Portable Machine for loading and unloading Goods. 


at reft in, the common interfeétion of the lines of the magneti¢ 
meridian or variation and dip; nor can any alteration of di- 
retion or motion of the fhip affect a dipping needle thus 
fufpended._ 

In confequence of this fimple contrivance, the motion or 
gyration of the graduated circles for either dip of variation on 
account of the motion of the fhip, becomes totally avoided ; 
for, on or in thefe magnetic inftruments there are no divi- 
fions whatever: the inftruments themfelves can be afforded 
for half the price of others; the navigator makes his obferv- 
ations like a man of fcience; and finally, he determines with 
expedition, eafe, and certainty, the magnetic dip and varia~ 
tion, to degrees, minutes, and feconds, 2. ¢. to the like ac- 
curacy that he can diftinguifh or read the fubdivifions fhewn 
by the vernier on the arch of his fextant: a circumftance ut- 
terly impoffible to be obtained even to whole degrees, it might 
be faid to half a dozen degrees, by any other conftruéted in- 
ftruments, as has'been herein before fufficiently verified. 


XII. Defeription of a Portable Machine for loading and un- 
loading Goods. By Mr, Gzorcer Davis, of Windfor, 
Berks *. ; 


Lu E ingenious contriver of this machine is certain, that, 
when made of its intended fize, it will be capable of loading 
a ton weight by one man only, and will be fo portable as not 
to exceed one hundred and twelve pounds in weight. 


Reference to the Figure of the Machine. (See Plate IX.) 


A, the winch, which turns the bar B. This bar has on 
it two, endlefs {crews or worms C,C, which work in the 
toothed wheels D, D. Thefe wheels are fixed fo the barrels 
E,E, round which the ropes F, F, coil, wind up, or let out 
the fame occafionally ; which ropes, pafling over the two 


* From the Tranfadtions of the ail Sor the Encouragement of Arts, 
Manufactures, and Commerce, 
A premium of fgrty guineas was given to Mr. Davis for this invention. 


pulleys 


Defeription of a Ventilator, &e. 393 


pulleys G,G, are brought round, and their ends, having 
hooks for that purpofe, are hitched into ftaples fixed to the 
front of the cart or other carriage: within thefe ropes the 
load H is placed on a common pulley I, which forms an in- 
clined plane, up which, by the turning of the winch, the 
ropes are wound upon the barrels, and the load raifed into 
the carriage. 

« KK, the frame, intended to reprefent the part of the cart, 
or other carriage, on which the machine is occafionally to 
be placed. 

‘ The whole of the barrels and cogged wheels are contained 
in an iron box L, the fides of which are reprefented in the 
figure as taken off, that the conftruction of the feveral parts 
may be thewn. 


Mil: Deferipiion ofc cbeap and efficacious Ventilator for 
_ preferving Corn on Ship-board. By Tuomas SourtnH, 


Ejq.*. 


“Due importation of grain is a precarious traffic. The 
produce of diftant countries, or even of thofe near home, 
when long in colle&ting, or long detained on fhip-board, is 
fubject to heat, foon becomes fetid, and is often fo far fpoiled .. 
and depreciated in its value as to fell for lefs than the original 
eoft. Herice the merchant, overwhelmed with loffes, regrets 
his patriotifm, grows fhy of importation, and, unlefs invited 
by a certainty of gain, drops the trade, even whilit the na-~ 
tion ftands in need of fupplies. . 

The remedy here propofed is a fimple, cheap, and, I truft, 
efficacious method of ventilating grain whilft confined on 
fhip-board ; fufficient, I prefume, to keep it {weet and mar 

ketable after fuftaining a tedious voyage. 


Defeription of the Ventilator, with References to the Figures 


thereof. (See Plate VII.) 
Fig. 1. is a cylindrical air-yeifel or forcing-pump, of lead, 
* From the Letters and Papers of the Bath and Weft-of-England Society 


for the Encouragement of Agriculture, 8c, 


VoL. V. 3E tin, 


394 Defcription of a Ventilator 


tin, or other cheap metal; its internal diameter being ten 
inches, and its length three feet; having a crutch- handled 
pifton to work with, and an iron parr viz. a hollow in- 
verted cone, two feet long, to condenfe the air, and increafe 
its power in its paffage downwards. This cylinder fhould be 
riveted or ferewed, by means of an iron collar or ftraps, ta 
the deck it paffes through, both above and below, as at aa; 
and fhould be farther fecured by fome hold-faft near 2, to 
keep it fteady in working. 

Fig. 2. is a bottom of wood, four inches and a half thick, 
with z a projecting rim at its bafe, for the metal cylinder to 
reft on, when cemented and {crewed to the wood. The centre 
of this bottom is excavated, for the reception of the crown 
of the nofle. In the fame figure the nofle is reprefented with 
its crown like a bowl-difh, to condenfe the air oradually, 
without refiftance, in its advance to the more contracted bafe 
of the inverted cone, z. ¢. the top or entrance of the nofle. 
About two-thirds down this nofle may be fixed a male ferew, 
as cc, for the purpofe hereafter mentioned. 

N.B. The forcing-pump fhould be cafed in wood: to 
protect it from outward bruifés, which would prevent the 
working of the pifton, and ruin its effects. The leather 
round the embolus fhould be greafed when ufed. 

Fig. 3. is acrutch-handle, faftened to the embolus A by 
its iron legs B, B. A isa cylinder of wood, cafed with lea- 
ther, fo as to fit well, but glide fmoothly in the metal cylin- 
der; having an opening as large as its ftrength will permit, 
for the free accefs of atmofpheric air. C is a valve, well 
leathered on its top, and, yielding downwards to the preffure: 
of the air when the pifton is raifed up. D is a crofs bar of 
iron, to confine the valve, fo that it may clofe inflantly om 
the return of the pifton downwards. 

Fig. 4. is a tin pipe or tube, of lefs than four inches dia- 
meter, and of fuch length as, when fixed to the bafe of the 
cylinder, Fig. 1, fhall admit the nofle d, Fig. 2, to within 
half an maa of the valve E, at the bottom of the wooden 
cylinder F, in Fig. 4; which valve E will then yield to the 
preflure of air condenfed in its paffage through the. nofle, 
and deliver it into the pipes below. This valve muft be well 

leathered 


for preferving Corn on Ship-board. 395 @ 

leatheted on its upper furface, and faftened with an hinge of 
leather to the cylinder it is meant to clofe: affixed to its bot- 
tom is the fpindle G, paffing through a fpiral {pring H, which, 
being compreffed on the defcent of the valve, will, by its ela- 
fticity, caufe it to rife again, clofe the aperture above, and 
retain the air delivered beneath it. On connecting this cy- 
linder with the upper end of the nofle, at ee, Fig. 2, we muft 
carefully prevent any lapfe of air that way, by a bandage of 
oakum fmeared with wax, on which to ferew the cylinder, 
like the joints of a flute, air-tight. I is a bar of iron, having 
a rifing in its centre, wide enough for the fpindle to play 
through, but at the fame time fufficiently contracted to pre- 
vent the paffage of the fpiral fpring. 

Fig. 5. is an aflemblage of tin pipes, of any lengths, fhaped 
fuitably and conveniently to their fituation in the fhip, to the 
form of which, when fhut into one another, they muft be 
adapted ; obferving only, that the neck be ftraight for a 
length fufficient to admit the lower end of the cylinder, 
Fig. 4. as high as the letter F, or higher. 

Fig. 6. To the middle pipe, which runs along the bottom, 
fhould be fixed a perpendicular one, fully perforated, to con- 
vey the air more readily into the centre of the heap; and this 
may have a conical top, as reprefented in the plate, perforated 
with a f{maller punch to prevent the air from efcaping too 
haftily. In large cargoes, two or three of thefe perpendiculars 
may be neceffary; and each fhould be well fecured by an iron 
bar g, fcrewed down, to prevent their being injured by the 
fhifting of the cargo in ftormy weather or a rolling fea. The 
top of the conical cap of thefe pipes may reach two-thirds 
up the cargo. 

Fig. 7. is a valve of the fame conftruction as that repre- 
fented in Fig. 4, but inclofed in a tube of brafs, having a fe- 
male ferew at ff, adapted to the male ferew c¢, on the nofle 
Fig. 2, and may then be inferted into the head of the pipe 
Fig. 5. This will add to the expence; but, in a large appa- 
fatus, is to be preferred, as a more certain fecurity from lapfe 
of air, than the junétion of the tube Fig. 4, to the neck ee 
in Fig. 2. 

N.&, ce is a neck of wood, making a part of the bottom 

3E2 Fig. 2, 


396 ' Defeription of a Ventilator 

Fig. 2, whereon to fecure the tube Fig. 4, when applied ‘to 
the nofle. The joints of the pipes, when put together for 
ufe, fhould be made air-tight, by means of bees-wax or fome 
ftronger cement, till they reach the bottom of the veffel, when 
there is no farther need of this precaution. | The horizontal 
pipes fhould run by the fide: of the kelfon the whole length 
of the hold. The tin plates of which K is made, fhould be 
punched in holes, like the rofe of a watering-pot, in two or 
three lines only at moft, and then formed into a tube, with 
the rough fide outwards. L may have four or five lines of 
the like perforations. M, and the reft, fhould gradually in- 
creafe in their number as they advance towards the middle of 
the hold, and continue fully perforated to the laft pipe, which 
fhould be clofed at its end to prevent the ingrefs of the corn. 
Tt is the centre of the cargo which moft requires ventilating, 
yet air fhould pervade the whole. Like the , trade-winds, it 
will direét its courfe to the part moft heated, and, having 
effected its falutary purpofe there, will difperfe itfelf to refreth 
the mafs, 

Where the hatches are clofe-caulked, to prevent the influx 
of water, vent-holes may be bored in convenient parts of the 
deck, to be bunged up, and opened occafionally, from whence 
the fiate of the corn may be known by the effluvia which 
afcend when the ventilator is working. 

The power of the ventilator is determined by the fquare of 
its diameter multiplied into the length of the ftroke, and that 
again by the number of ftrokes.in any given time. 

To find the area of a circle, and the folidity of a cylinder 
raifed on that circle, Archimedes gives the following propor- 
tion :— 


‘As 1 is to .785398 decimal parts, fo is the fquare of the 


diameter to the area of the circle. 
And, as 1 is to .785398, fo is the fquare of the diameter, 
multiplied by the height, to the folidity of the cylinder. 
The cubical contents, ‘both of eylinders and tubes, are 
found in the fame manner; their difference confifting not 
in fhape, but folidity, the latter being hollow. 
Then, to find the contents of a cylindrical veffel whofe in- 
ternal diameter is ten inches, multiply that into itfelf, and 
the 


Sor preferving Corn on Ship-board. 3907 


the fquare thus obtained, multiplied by .7854, wilk give the 
contents of the circle in cubic inches; which, multiplied 
again by twenty-four inches or lengths of the ftroke, being 
the proportion of the barrel filled with air, gives in cubic 
inches the amount of each difcharge on the defcent of the 
pifton. As thus: 
: Inches. 
Internal diameter of the pump or tube 10 
30 


= 100, or fquare of the diameter; 
which, multiplied by .7854, to bring the contents of the fquare 
to the contents of the circle. 
Which, multiplied by the 78,5400 Contents of the area of the circle. 
length of the firoke, i 24 inches, produces 1884 cubic 


inches. 
3141600 
15705800 

18849600 
which, divided by 231) 1884.9600(8-1600 gallons, which is gos ths 
vis. the number of cubic inches —— more than § gallons at a 
in a wine gallon, quotes 8 galls. 369 ftroke; allow thefe deci- 
pea mals for wafte of air in 
1336 eachftroke;and6oftrokes 

to be made ina ininutes 
Then - - --- --~ 8 gallons difcharged at a ftroke, 


multiplied by 60 the number of ftrokes 


amounts to 480 gallons per minute ; 
which multiplied by - - 60, the minutes in an hour, produces 28S09 
oS gallons in that time; 
and that, divided by 252)28800(114.3 tons. 
(the number of 


gallons in a 360 
ton, bath wine 

and fhip mea- 1080 
fure) quotes 114 ——— 
tons jn an hour, #720 


Then, fyppofe the area of the hold of a fhip to be = 320 
tons, and, when freighted, the interftices between the grains, 
together with the area between the furface of the corn and 
the 


398 Defeription of a Ventilator 


the underfide af the deck = 5 tons = to the quantity of mé« 
phitic air confined ; fuch being the lighteft fluid, the major 
part of it would, ie after the commencement of the ope- 
ration, be Seen, by the atmofpheric air, to vent itfelf at the 
holes previded for that purpofe; and the remainder of the 
hour being employed in the like ventilation, five tons of freth 
air would pafs above twenty: times repeatedly amidft the 
grains, to cool, refrefh, and fweeten the cargo. A purifica- 
tion thus adminiftered once in eight-and-forty hours, would, 
I conceive, be amply fufficient to preferve the corn from taint 
or injury, be the voyage ever fo tedious ; and unlefs it fhould 
by neglect. have overheated and grown together, or fettled 
- teo clofe, the labour would be that of a boy only; for the 
dairy-girl at her churn works harder than he otherwife need 
to do at this. 

My air-veflel is, for the fake of cheapnefs, confined to the 
narrow diameter of ten-inches ; but, as the contents of circles 
are proportionate to the fquare of their diameters, by enlarg- 
ing that, you increafe their power accordingly ; wherefore, 
fy extending the diameter to fourteen inches, the contents 
will be nearly doubled; and, by adding ten inches more ‘to 
the Jength of the ftroke, you almott treble the difcharge of 
No. 1, and obtain a power capable of ventilating a cargo of 
400 tons within the hour. But the air-veffel muft be length- 
ened; the pipes at the fame time enlarged; the metal of 
which the whole is conftructed be in fub{tance proportion- 
able; and the labour be that of a man, or perhaps two upon 
occafion. 

A ventilator, on the plan and dimenfions here propofed, 
would come within the compafs, I fhould think, of five or 
fix guineas. One on the larger feale, caufed by the increafed 
fubftance of the metal, and the extra fize and length of the 
pipes, might amount to twenty; which, in either, 1s under 
fourpence per quarter on the firft cago; and as they will 
laft many years if well painted, and, when not in ufe, taken 
to pieces and put carefully by, I flatter myfelf it is an expe- 
riment well worth trial; particularly if a premium be offered 
to the fhip-owner, who, by means of fuch machine, imports 


his corn pure and untainted from a diflant land. 
Objeions 


s-% 


« Jor preferving Corn on Ship-board. 399 


Objeetions ee to the fuppofed Effee of the Ventilator, over- 
ruled, ut is hoped, by the Confiderations which follow them. 


Firtt, The holes pierced in the tin tubes which are to lie 
under the corn, feem capable of iffuing (efpecially if an effort 
be made upon them) a much larger quantity of air than the 
forcing-pamp will fupply in a given time. Confequently, a 
given quantity of thefe holes, under a given preffure, will 
be capable of iffuing the whole fupply of air, without ang 
affiftance from the remainder. 

Secondly, If thefe pofitions are juft, it muft happen, that 
if a cargo of corn be unequally circumftanced in relation to 
its permeability, the whole of the air difcharged by the pump 
will iffue through the more permeable parts of it, without 
affeGting, in any degree, the /e/s permeable ones. 

Thirdly, In cargoes heated in any degree, and in thofe 
infeed by that worm which faftens grains together by a 
web, the parts moft affected become niuch more clofe and 
denfely packed together than the reft, either by the fwelling 
of the heated grains, or by the web and dung of the worms 
which occupy the intervals between the grains. 

If fo, the parts of a cargo which require the moft yentila- 
tion will receive the leaft; but, im all cafes, it feems likely 
that the air difcharged will not regularly permeate the whole 
of the cargo, but will pafs through the parts where the grain 
lies lighteft, and leave untouched thofe parts wicre it is 
moft clofely packed together. 


Anfwer to the preceding Obje&tions. 


Though the holes appear numerous, they mutt be fmall, 
left the corn gain admiffion; and many (efpecially of the 
uppermoft) will be nearly, if not totally, topped by the pre!- 
fure of the grains upon them.. Befides, the pipes which 
convey the air towards’ the centre are not meant to be fo 
fully perforated as thofe at and beyond it; and all may be 
ftill lefs fo, if im practice found neceffary. But as the quan- 
tity of air delivered by the forcing-pump within five feconds 

7 of 


© 


406 Défeription of a Ventilator 

of time is equal to the contents of fixty * feet of four-inch 
pipe within the firft minute, the air (notwithftanding the 
manifold perforations, obftruéted as it is in meandering 
through a mafs fo nearly compacted as the bottom of the 
cargo muft neceflarily be by the preflure of the heap above) 
will undoubtedly reach to the end of the Pipes, and confe- 
quently affect the cargo even there. 

Be it farther obferved, that the flux of air Peg into 
an half-inch ftream, in its paflage through the nofle, to en- 
able it to overcome the refiftance of the fpiral {pring H, no 
fooner paffes the valve E, than it expands itfelf to the com- 
pafs of the pipe; by which expanfion, and extenfion (at the 


* Thus calculated: 


Inches. 
60 feet 4 
x 12 inches yet 
~ Produces 720 inches 16 the fquare of the diaméter of the 
as a multiplier. X 57854 pipe. 


== 12,5664 or area of the circle. é 

x 720 length of the pipe in inches. 

Which, divided by 231)9047,;8080(39,1679 gallons and decimal ‘parts, 
— the whole capacity 
2117 of 60 feet of pipe. 


3848 


221, XCe 


Then, a fingle difcharge of the forcing-pump being eight gallons, five 
fach difcharges amount to 4o gallons, which is more than equal to the 
contents of 6 feet of four-inch pipe. 

And as on the larger {cale of ventilators the pipes need not exceed the 
fame diameter, the power of the air injeéted, when its egrefs is ftopt, wilk 
increafe fufficiently to force its way through webs, mats, and other obftruc-. 
tions, though impervious to the atmofpheric fluid, unaflifted by fuch me- 
chanic aid. 

fame 


a ane a ee 


for preferving Corn on Ship-board. 40% 


fame time) forwards, its power becomes fo weakened, that 
{mall egrefs only will be made, till the pipes are filled with 
a fluid more denfe than -atmofpherie air, whieh will then, as 
is juftly noticed, fue where it finds the leaft obftruction, 
unlefs attracted to the {pot moft heated. 

Many circumftances may caufe one part of the cargo to be 
lefs permeable than the reft; fhould it prove fo, the means 
readily offer for airing and purifying even this. 

Suppofe the hatches to be caulked down, and the hold 
made impervious to waters in fuch eafe, the lapfe of aif, 
under the obftructions met with in its paflage, could by no 
means keep pace with the influx from the forcing-pump; 
confequently, if the holes in the deck, defigned for its exit, 
be kept clofe-ftopped till the pumper feels refiftance, all the 
intervals of the cargo, be they ever fo minute or irregular, 
muft be occupied by freth air, which, when permitted to 
efcape, will carry off impurities with it. And. thus, by 
ftopping and opening fuch vents repeatedly, no part of the 
cargo could mifs of purification. and this perhaps may be 
the beft mode of adminiftering it. 

Prevention is better than a cure. 

In a veffel equipped with the apparatus defcribed, the in- 
attention muft be great, if the corn be fuffered to fuftain any. 
injury at all. By an early ufe of it, per{piration and damps 
will prefently be dried away; heating of courle will be pre- 
yented ; and even the production of the pernicious grub al- 
Juded to: for, be the nidus of its eggs ever fo productive, 
their embryos will, not vivify, without moifture to fuftain 
them. Wherefore, it fhould feem that the corn-merchant 
in future will have little to fear, fave the influx of fea-water 5 
and even this (if in {mall quantities) wall, by the frequent ufe 
of the ventilator, eradually dry away. ' 


wl byouey. 3F INTEL- 


[ 402 ] 


INTELLIGENCE, 


AND 


MISCELLANEOUS ARTICLES. 


ROYAL SOCIETY OF LONDON. 


On the 30th of November latt, the anniverfary meeting 
of the Society was held. Sir Godfrey Copley’s gold medal, 
which is difpofed of yearly on this day to the moft deferving 
member, was awarded to the Rev. Mr. Hellings. 

The receipts of the Society for the year were declared to 
have been 1736 /. and the difburfements 1563 /. 

The meetings of December the 5th and 1ath were occu- 
pied principally in reading the conclufion of Dr. Herfchel’s 
paper on the power of penetrating into fpace by means of 
telefcopes. - According to the Doétor’s obfervations, it is 
impoflible with the naked eye to fee any ftar fmaller than 
thofe of the 8th, gth, or roth magnitude. With his 40 feet 
refleStor he has difcovered ftars which muft be three hun- 
dred thoufand times more diftant than the neareft fixed ftar. 
Where are the bounds of creation! 

At the latter meeting, an abftraé of a regifter of the wea- 
ther at Lyndon in Rutlandfhire, kept by Mr. Barker, was 


‘read ; as was alfo a paper on annuities, refpeéting. the con- 


tingencies of three, lives, by Mr. Morgan. 
December 1gth. A paper, by Mr. "yondan; on the irides 


furrounding the fun, moon, &c. was partly gone through, 
‘when the Society adjourned for the Chriftmas holidays: 


January 9th, the conclufion of Mr. Jordan’s paper was 
read; as was alfo a paper by Mr. Anthony Carlifle, on 
fome peculiarities in the arterial fyftem of certain animals, 

On the 16th and 23d, a paper on found. 

COMET. 

C. Lalande has announced that, on the 26th of December 

laft, his fellow-labourer Mechain difcovered a comet near 


the tar s of Serpentarius, which could be diftipguithed by 
the 


Subflitute for Cinchina.—Difeafed Elms. 403 
the naked eye. It had a tail of a degree, and was proceed- 
ing in a fouthern direétion. 

SUBSTITUTE FOR CINCHONA, 

C. Zannetini, a phyfician who attended the French army 
in Italy, has madé fome experiments, by which it appears 
that the flowers and feeds of the common nettle (Urtica di- 
oides Ltn.) may be employed in fever inftead of cinchona. 
This fubftitute was attended with a fuccefs beyond all ex- 
pectation, in tertian and quartan malignant fevers. The 
nettle often produces a fpeedier effeét than bark, for it heats 
in a gréat degree, and, when the dofe is pretty ftrong, occa- 
fions a lethargic fleep. The dofe muft never exceed a dram, 
and is given in wine two or three times in the courfe of 
24 hours. Zannetini found this medicine of great fervice to 
guard againft that total exhauftion which forms the principal 
character of malignant fevers; and he recommends a flight 
infufion of it in wine as an excellent prefervative for thofe who 
refide in marfhy and infalubrious diftrias. In employing 
the nettle in fever, Zannetini gives the fame caution as ought 
to be abferved in regard to cinchona, that is, that it muft not 
be employed where there is an inclination to inflammation, 
or where a continued fever, arifing from obftructions, exifts. 
This difcovery is not unworthy the attention of phyficians, 
and deferves at Jeaft to be farther inveftigated, as a great deal 
would be faved if cinchona could be entirely difpenfed with. 

CURE FOR DISEASED ELMS. 

C. Boucher, fecretary to the Society of Emulation at Ab- 
beyille, has lately publifhed a memoir on the difeafes which 
attack elms, and the method of curing them, from which 
the following is an extract :—‘ Elms are frequently attacked 
by ulcers, which at length deftroy a great number of thefe 
valuable trees. Duhamel fuppofed that this malady might 
_ be afcribed to a plethora of the fap; and C. Boucher, by 
numerous experiments, has eftablithed this fa&t, and difco- 
yered aremedy. He obferved, that local ulcers never attack 
the tree on the north fide, but almoft always on that expofed 
to the fouth. The elms chiefly fubje& to it are thofe planted 
in marthy ground, and in the neighbourhood of rivers. The 
ulcer is generally at a little diflance from the earth, feldom 

3F 4 more 


404 Difeafed Elms.—New Pneumatic Apparatus. 


more than five or fix feet above it. This difeafe, arifing fromt 
a fuper’bundance of fap, differs from another difeafe of the 
elm defcribed in the Journal d’ Hifioire Naturelle* for the 
vear 1789, in this cireumftance, that the liquor, when 
expofed to the atmofphere, foon acquires the confiftence of 
a.gum, and has a very faccharine tafte. 

To cure the trees attacked, C. Boucher pierced each of 
them with an auger, which he inferted in the ulcer itfelf, 
and then fitted to the hole a tube which penetrated to the 
depth of 1°10 inches. Sound trees pierced in this manner 
yield no liquor; but thofe which are difeafed-give a more 
abundant quantity, in proportion to the ferenity of the wea- 
ther, and as the wound is more expofed to the fouth. This 
effet is fufpended by ftormy weather and. high wind, He 
obferved that at the end of two or three days the efflux of the 
fap ceafed, and that the wound dried up and was healed. 

This, therefore, is a fimple and eafy method of radically 
curing elms attacked with this difeafe. It is probable that 

. the fame procefs applied to other vegetables, and particularly, 
to fome fruit-trees, would produce a like effect. Pliny, Co- 
lumella, and Palladius, mention the fame means as haying 
been employed by the ancients, but it has not been before 
practifed for many years. 

C. Boucher has completed his obfervations on the elm, 
and proved that this tree is not an exotic, as fome authors 
have advanced. The fiudy of the ancients has proved to him 
that it exifted in Europe in the remoteft periods, and very 
eyident remains of it have been found in old mofles, 

The analyfis which C. Boucher made of the fap of the elm 
fhewed that it contains a pretty large quantity of the acetite 
of pot-afh, a little of the acetite of lime, a certain quantity of 
vegetable matier or faccharine mucus, and a pretty large 
quantity of the muriat of lime. There exift in it, alfo, flight 
traces of the fulphat and muriat of pot-afh. This is nearly 
the fame analyfis as that before announced by C. Vauquelin, 

NEW PNEUMATIC APPARATUS. 

Mr. H, W. Pepys jun. has conftructed a mercurial ex- 

haufter on the principle of the Torricellian yacuum. The 
* No. 5 and 6, ; 
inventor 


Deaths. 405 


inventor has promifed to enable us to lay the plan of the ap- 
paratus, with fome of the moft interefting of thofe experi- 
ments which have yet been made with it, oe our readers 
in a future number. 

DEATHS. 

On the 1gth of December, C.Montucla, author of an ex- 
cellent hiftory of the mathematics. Two volumes only of 
the new edition of this work were publifhed before the au- 
thor’s death, but fortunately all his corrections for the re. 
mainder were finifhed. ane 

At Paris, on the 1f of January, the celebrated naturalift 
Daubenton; the friend’ and fellow-labourer of Buffon. He 
was born at Montbard-in Burgundy in the month of May 
1716. He fiudied medicine, and intended to follow that 
profeffion in. his own country; but Buffon, being appointed 
intendant of the king’s garden in 1735, prapofed to Dau- 
benton to refide with him, to apply to natural hiftory, and 
to affift him in the grand Jabours which he was then about 
to undertake. In 1740 the fate and tafte of Daubenton were 
determined for his whole life. More than half a century de- 
voted to the formation of the cabinet of natural hiftory, which 
in 1750 was only a plain drug-fhop belonging to Geoffroy, 
which he arranged methodically and dartehied with produc- 
tions of every kind, has given him a diftinguifhed rank 
among naturalifts. Being pie ae into the “Keadetny of 
Sciences in 1744, he never ceafed to enrich the collection of 
its memoirs with various papers for nearly fifty years. The 
greater part of them contain new facts and ideas refpe&ting 
the clafijfication of fhells, on the hippopotamus, the fhrew-~ 
moufe, bats, foffil bones and teeth, the fituation of the 
great occipital foramen in man and animals, rumination 
and the temperament of {heep, a defcription of feveral kinds 
of new animals, or animals little known. He was interred 
with great pomp on the 3d of January in the garden of plants, 
His funeral was attended by more than 500 perfons, and two 
orations were pronounced on the occafion by C, Lacepede 
and C. Fourcroy. 


LLL LLL 


3 F 3 INDEX 


{ 406 J 


INDEX ro VOL. V. 


Acrp, on the effects produced by the fluor, page 29. 
Acorns, a fubititute for coffee, 309. 
Adrianople red, on the Grecian method of dyeing, 325. 
Agenda for forming a theory of the earth, 24, 135, 217. 
Agriculture, on different forts of lime ufed in, 209. 
Air-furnace, defcription of Mr. Howard’s improved, 199, 
Amer (bitter) drawn from animal fubftances, 286. 

Animals, experiments on /iving, 300. 

Animal eleGricity, obfervations on, 1, 140, 270. 

Animal fubftances, on fome peculiar matters drawn from, 286: 
Affaying of iron ores, Muthet on, 236. 

Afironomy, a comet feen in December 1799, 402+ 

, Lalande on the place ofithe aphelion of Mars, 309. 
, on the comet feen Sept. 1799, 38. 

» Herfchel on the fun and fixed itars, 114, 222. 
Aimofphere, Mann on the flux and reflux of the, 105. ' 
Azara on the Spanifh American wild horfes, 330. 

Azimuth compas, imperfe&ions of the common, 378. 

Axotic gafes, prize queftion refpecting, 296. 


Bark, a {ubftitute for, as a medicine, 403. 

Bark, on the quantity of tanning principle and gallic acid in various 
kinds of, 321. ek os 

Beet-roots, Klaproth on fugar from, 96. 

Beet-root, a fubftitute for coffee, 309. 

Liggin on the tanning principle and gallic acid, 3216. 

Blindnefs cured by vital air, 196. 

Slaft-furnace for {melting iron, defcription of, &c. 40, 124, 366. 

Bleaching, account of a new method of, 351. 

Boffe on inks that refift oxy-muriatic acid, 353. 

Brain, oppreffion of the, cured by vital air, 196. 

Brown's travels through Egypt and Syria, &c. 69, 192. 

Burns's improyements applicable to fire-grates, &c. 264. 


Carbonat of pot-afh, an eafy and cheap way of preparing, 36. 
Caft feel, fome curious experiments on the making of, 89, 201. 
Caterpillars, a recipe for deftroying, 16. Bist) 
Cavanilles on the earthquake in Peru in 1797, 318. 

Chaptal on the art of fcouring ftuffs, 261. 

on a new method of bleaching, 351, 

Chromat of iron difcovered in France, 300. 

Cinchona, ‘a fubltitute for, 403. © 


> limatesy 


INDEX. 403 
Climates, on the changes in the temperature of, 18. 
Clutterbuck’s objections to the Mitchillian theory, 1go. 
Coffee, fubititutes for, 309. 
Comet, feen in December 1799, 402. 
» Lofft on the one feen September and October 1799, 38. 
Copal, to diffolve in fpirit of turpentine, 64. 
in alcohol, 6. 
Copper, on the art of hardening, 271. 
Corz, to ventilate on fhip-board, 393. 
Cottoz, a new method of bleaching, 351. 
Cotton yarn, Grecian method of dyeing red, 325. 
Cow-pock, communication from Dr. Pearfon on the, 313. 
Crane, machine that anfwers for a, 392. 
Cures, by pneumatic remedies, 94, 196, 2916 


Davis’s machine for loading and unloading goods, 392 
Deaths, 101, 312; 405- 

Deformeaux on the preparation of writing ink, 157. 
Diavwond, Guyton on the combuftion of the, 55, 174. 

-, ufed in the converfion of iron into fteel, 89. 
Dipping needle, imperfeCtions of the common, 379. 
Dif-afes cured by vital air or oxygen gas, 94, 196, 29I~ 
Diftillation, the Indian method of, 7. 

Dolomicu’s defcription of the Paliorum Lacus, 77. 
Drawings, procefs for producing the lights in itained, 67. 
Dyeing, a {pecies of mufhroom fit for, 99. 

: » a hint for the animalization of ituffs for, 99. 
Dyeing red, on the Grecian method of, 325. 


Earth, agenda for forming a theory of the, 24, 135, 217. 
Earthen-ware, analyfis of the earths found in common, 288., 
Larthquake, obfervations on that in Peru in 1797, 318. 

EleGoral Academy of Sciences at Manheim, proceedings of, 95, 296. 
Eleétricity, Hemmer’s obfervations on anizial, 1, 140+ 

LileGricity, {parks obtained from ice, 208., 

£ilms, a cure for difeafed, 403. 


fabbront on the chemical aétion of metals on each other, 268: 
Felix on the Grecian method of dyeing cotton red, 325. 

Fire occafioned in a lake by an earthquake, 320. 

Fire-ball, account of one feen 22d Sept. 1799, 38. 

Fire-grates, Burns’s improvements on, 264. 

Fog, on the nature of that of 1783, by De Lamanon, 80. 
Fourcroy and Vauguelin on human urine, 43. 

Fofiil wood, Villars on fome found at a great height, 299: 
Furnace, defcription of Mr. Howard’s improved air, 190. 
———, defcription, &c. of a blaft one for {melting iron, 40, 124. 


Gadd on the nature and properties of Lapis fungifer, 279. 
Gallic acid, quantity of, in different kinds of bark, 321. 
Galls, a fubftitute for, 310. 
Gazoumster, defcription of Pepys’s mercurial, 154+ 
- 6 Geology, 


408 INDEX. 


Geology, agenda to promote the knowledge of, 24, 135. 217: 

Glafs, to folder, 311. 

Goods, machine for loading and unloading, 392. 

Gum arabic, on the real origin of, 239. 

Guyton on the combultion of the diamond, 55, 174+ s 

Guyton on the converfion of iron into ftecl by means of the dia- 
mond, 8 

Guyton on the gravity of tungften, 308. 


Heat, inquiry into the weight afcribed to, 162. 

Hemmer’s obfervations on animal electricity, 1, 140. 
Herholdt’s new theory of refpiration, 300. 

Herfchel on the fun and fixed flars, 114, 222. 

Hyelm on the art of hardening copper, 27. 

Holyoke’s method of preparing carbonat of pot-afh, 36, 

Horfe chefinut, a fubltitute for eatracium ching, 310. 

Horfes, account of the Spanifh American wi/d,, 330s 
Howard's improved air-furnace, defcription of, 190. 

Hydra, ingenious explanation of the allegory concerning, 151. 


Indigo refin, Brugnatelli on, 97- 

dak, an improved writing, 98. To prepare, 157, 353- =. 
Tron, Muthet on the manufadture of, &c. 49,97, 124,200,256, 366. 
, converfion of into fteel by means of the diamond, &c. 89, 201, 
—, fingular oxydation of, 208. 

——, experiments on chromat of, 305. 

dron ores, Mufhet on the affaying of, 236. 

Fuch, curious notices by Dr., 207, 208. 


Klaproth on fugar from beet-roots, 96. 
Kortum on the aGtionof the fluor aeid, 29. 


Jake Palius, defcription of the, 77- 

Lamanon on-the fog of 1783,. 80. 

Lapis fungifer, on the nature and. properties of, 279. 
Learned Societies, information refpeting, 955 197>.296).402. 
Le Beck on the pearl fifhery at Ceylon, 325. 

Levant red, onthe Grecian method of dyeing, 325. 
Lime, on different forts of, ufed in agriculture, 209. 
Linneus, monument to, 309. 

Linfeed ail, to feparate the mucilage from, 62. 
Liver, a difeafed, cured. by vitabair, 94. 

Lofft, Capel, efq.. on. fiery. meteors, 38. 

Longitude, Nugent’s method of difcovering:the,; 378. 


Magnefia, to be avoided.as'a manure, 210. 

Magnetic-poles, a new theory refpeCting the, 378. 

Mann on the gradual changes in temperature and foil in differeng 
climates, 18. 

Mann onthe flux and reflux of the atmofphere, 105. . 


Manganefe, to prove the prefence of, in'vegetables, 98, . 
Medical 


INDEX. 409 

Medical pneumatic infiitution, elablithed at Briftol, 301: 
Mercurial gazometer, defeription of Pepys’s, 154. 
Metal, chemical a¢tion of, on each other, 268. 
Meteorclogical remarks, 38. 
Meteors, account of feveral, 199. 
Mining} hiftory of, in Devon and Cornwall, 357. 
Mitchill’s inquiry into, the effects of feptic acid on flefh, 146. 
Mitchillian theory, objections to the, 188. 
Monument to Count Rumford, 205, 312. 

to Linneus, 399. 
Morocco leather, the method followed at Fez and Tetuan to dye, 7. 
Mufbet on the manufacture of iron, &c. 40, 97, 1245 236, 366. 
Mufbrooms, on the growth of, 279. 


Natural hiftory, notices relative to, 109, 

Navigatitn, new theory for the improvement of, 378. 
Neitles, a fubltitute for cinchona, 403. 

Nicholfon’s procefs for producing lights in drawings, 67 
Nugent on the magnetic poles and the longitude, 378. 


Ores, Muhhet on the aflaying of iron, 236. 
Oxygen gas, a cure for different difeafes, 94, 196, 291° 


Paliorum Lacus, defcription of the, 77: 

Pearl fifberj, account of the, in the gulph of Manar, 335. 
Pearfon on vaccine eruptions, 313. 

P-pys, defcription of his mercurial gazometer, 154. 

Peru, earthquake in, in the year 1797, 318. 

Pefiilential difeafes, Smith on thofe of ancient armies, 242. 
Pictra fongaja, on the nature and properties of, 279. 
Plants, Ratn on the nutrition of, 233. 

Pneumatic apparatus, Pepys’s new, 404, 

medicine, Dr. Thornton on, 94, 196, 291. 
inftitution, obfervations made at the, 301. 
Polytechnic fchook, experimeuts at the, on the diamond, 55, 174. 
Pot-afb, Mitchill’s obfervations on, 146. 

Pottery, analyfis of feveral kinds of, 288. 

Prize quefttons, 296, 297: 

Prouft on manganefe in vegetables, 98. 


Rafn on the nutrition of plants, 233. 

Refpiration, Herholdt’s new theory of, 300. 

Royal Society of London, tranfaétions of the, 197, 402. 
Rumford, Count, monument to, 205, 312, 

Rumford’s inquiry into the weight alcribed to heat, 162, 


Sal aératus, an eafy and cheap method of preparing, 36. 
Sandarac, on the real origin of, 239. 
Sauffure’s agenda, 24, 335, 217. 
Schoufboe on fandarac and gum arabic, 239. 
Scouring of Puffs, Chaptal on the art of, 26t. 
: Septic 


ee INDEX. 


Septic (nitric) acid, effets of, on animal flefh, 146. 
Sheldrake on purifying linfeed oil, &e. &e. 62. 

Small-pox, on vaccine eruptions like thofe of the, 313. 
Smith on pettilential difeafes, 242. 

Society of aciexces at Haerlem, prize queftions by, 297- 

Scil and temperature of climates, on the gradual changes in, 18. 
South’s ventilator for corn, defcription of, 393. 
Steel, diamond applied to the making of, 89; fee alfo 201, 
Steel, Muthet’s experiments on the making of, 201. 
Still for diftil'ation, the Indian method of conftru€ting, 7. 
Stoves, Burns’s improvements applicable to, 264. 

Stones, on the action of the fluor acid upon, 29. 

Sugar from bect-roots, Klaproth on, 96. 

Sugar, on the luminous appearance produced by, 207. 
Sun and fixed fiars, Herfchel on the, 114, 222. 


Taiffart and Vauquelin’s analyfes of chromat of iron, 306. 
Lanning principle, on the quantity of, in various barks, 321. 
Taylor on mining in Devon and Cornwall, 357. 
Temperature and foil of climates, on the gradual changes in, 18. 
Tennant on different forts of lime ufed in agriculture, 209. 
Tindure of barks a {ubftitute for, 310. 

Travels, account of Mr. Brown’s, in Egypt, &c. 69, 192. 
Travels in Africa, by Hornemann, 310. 

Trees, method of checking decay in, 307. 

Tung fren, on the gravity of, 308. 

Turkey red, on the Grecian method of dyeing, 325. 


Uleerated legs cured by vital air, 291. 
Urine, natural, chemical, and medical hiftory of, 43. 


Faccine inoculation, on eruptions attending the, 313. 
Van Mons on writing ink, 98. ' 

animalizing ftuffs for dyeing, 99. 
Farnifh, to prepare copal, 64. 
Vauguelin and Fourcrey on human urine, 43+ 
Vauquelin on the analyfis of earthen-ware, 288. 
Fauquelin and Taiffart’s analyfes of chromat of iron, 306. 
Vegetables, experiments on the nutrition of, 233. 
Ventilator for preferving corn on fhip-board, 393. \ 
Volcanic ifland near Iceland, on the, 280. 


Welter’s experiments on animal fubftances, 286. - 
Writing ink, on the preparation of, 98, 157- 


Zannetini’s fub{titute for ciachona, 403. 


END OF THE FIFTH VOLUME. 


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