C H E M : 
Ing to inftru&ions drawn up by him. See the article 
Contagion. 
Thus we have given the general phenomena obferved 
in the putrefaction of animal fubftances; whence may be 
clearly feen, how much the pjiilofophy of animal fub¬ 
ftances and the fcience of medicine may expeft from 
chemiftry, when thefe two fciences are connected toge¬ 
ther. There is a great difference between the putrefac¬ 
tion of the parts of living animals, and that of their dead 
organs. The motion which exifts in the former, lingu- 
larly modifies the phenomena of this alteration ; and 
phyficians have frequent opportunities of obferving the 
difference between thefe two ftates, with refpeft to putre- 
faCliou. Befides this, every humour, and every folid part, 
feparated from a dead animal, has likewife its peculiar 
way of putrefying. The mufcular, membranous, or pa¬ 
renchymatous, texture of the organs; the oily, mucila¬ 
ginous, or lymphatic nature of the humours ; their con- 
iiftence, their ftate with refpeCt to that of the animal 
which afforded them, all influence the putrefactive motion, 
and modify it in a thoufand manners, perhaps impoflible 
to be eltimated. And how greatly will the difficulty of 
the fiubjeCts be increafed, if we add to this enumeration, 
the ftate of the air, its temperature, elafticity, weight, 
drynefs, or moifture; the expofition of the putrefying 
fubftance in various places, and even the form of the 
veffels which contain it; all thefe circumftances being 
capable of varying the phenomena ? It mull therefore 
be allowed, that the hiftory of animal putrefaClion is 
fcarcely begun, and that it demands an iinmenfe feries of 
inquiries and experiments. 
Such are the phenomena which take place, when ani¬ 
mal matters putrefy, and are decompoied; but as the 
refult of this decompofition in different mediums throws 
great light on the knowledge of the revolutions of the 
globe, let us conflder, for an inltanf, what happens to 
thefe matters, in their various decompofitions, in the dif¬ 
ferent parts and fituations of the earth. 
The bodies of animals plunged into water, firft fwell 
up; elaftic fluids are difengaged; the water dilfolves a 
great part of their principles, decompofes another part, 
and difperfes the different principles of thefe bodies 
among the great maffes that conftitute rivers and ftreams ; 
whence feveral favage nations expofe dead bodies in rivers, 
and commit their deltruCtipn to the water. 
Different phenomena take place, when the bodies of 
animals are buried beneath the ground. In thefe cafes 
putrefaClion takes place more or lefs flowly, the fluids 
and the folids finiffi, by being reduced-almoft entirely in¬ 
to azotic gas, carbonic acid gas, hydrogen gas, and am- 
moniacal gas. All thefe elaftic fluids being filtered through 
the earth, are flopped and partly fixed, and render the 
ground black, greafy, and fetid. They faturate it, as it 
were, with thefe products of putrefaClion, until the dif- 
folving power of water and air, the vaporization effected 
by heat, and the abforption by vegetables, deprive the 
ground of the fluids with which it is impregnated. Thus 
it is that nature, by flow decompofitions, reduces the 
bodies of animals, deprived of life, to more Ample fub¬ 
ftances, deltined to enter into new combinations. 
This decompofition, confidered on every part of the 
globe at once, in the earth, in the water, or in the air, 
produces great changes, which the philofopher ought to 
appreciate. By obferving the vail extent of the feas, and 
the immenfe quantity'of animals which inhabit them, 
we perceive thofe animals periffi in enormous maffes, and 
fuffer a decompofition, which produces phenomena hi¬ 
therto not fufficiently examined. What becomes of tfie 
immenfe remains of animal matters ? To what fuccef- 
five revolutions are thefe ruins of living beings expoled ? 
It is known that the waters of the fea contain the mu- 
riats and fulphats of foda, of lime, and of magnefia. It 
cannot be doubted, but the muriatic acid, magnefia, lime, 
and foda, are continually formed in this vaft laboratory. 
Perhaps the formation of many of thefe fubftances may 
Vol. IV. No. 304. 
S T R Y. 373 
take place during the life of thefe marine animals; but 
fome otliers are certainly owing only to the decompo¬ 
fition of the fame fubftances after death. It cannot be 
denied, that the ftrata of calcareous matter, which con- 
liitute, as it were, the bark or external covering of the 
globe, in a great part of its extent, are owing to the re¬ 
mains of the fkeletons of fea animals, more oriel’s broken 
down by the waters; that thefe beds have been deposited 
at the bottom of the fea; that fuch is likewife the origin 
of bitumen, and more especially pit-coal, which is depo¬ 
fited in very thin and extended ftrata, which likewife 
occupy a part of the globe. Thfere is, therefore, in the 
fea, a never-ceafing caufe of the decompofition of water; 
numberlefs agents continually feparateits principles, and 
are theml'elves changed. Immenfe maffes of chalk, de¬ 
pofited on its bottom, abforb and fix the water, or con¬ 
vert it into a folid fubftance, part of the liquid which fills- 
its vaft bafons. 
From thefe confiderations, refpefiting the decompofition. 
of animal fubftances in the earth, in the air, and in the 
water, united to all the data afforded by chemiftry, it 
follows, that the external ftrata of the globe are no longer 
what they were at the moment of its formation; that it 
increafes in folidity and extent by the l'ucceffive and un¬ 
interrupted augmentation of thefe depolitions; that the 
foil we inhabit is modern and factitious; that it does not 
belong to minerals; that this l'uperficial foil is owing to 
the flow decompofition of animals and vegetables; that 
water is continually diminifhed in quantity, and changes 
its form; that one part being decompofed, fnrniflies one 
of the bafes of the bodies of vegetables and animals ; that 
another part is rendered- folid in. the calcareous ftrata 
added to the globe ; that the atmofphere mult have been, 
modified by all thefe fucctffive changes ; that vegetables 
continually influence the atmofpheric air ; and that the 
folar light is greatly concerned in all thefe mutual de¬ 
compofitions. Though it feems impoflible to determine 
the times which have fucceflively beheld the decompofi¬ 
tion of water, vegetation, fermentations, putrefaClion, the 
formation of faline fubftances, bitumens, calcareous mat¬ 
ters, and the modifications of the atmofphere ; yet philo- 
fophy and chemiftry, enriched by modern difcoveries, 
fhew. us at leaft. that thefe phenomena have taken place 
at different epochs; that they continue to modify the. 
aCtual ftate of the planet we inhabit; and that if. matter 
be one and the fame thing, with refpeCt to its mafs and-, 
intimate nature, as great philofophers have thought, yet 
its form being continually varied by the combinations it 
experiences, mull gradually produce great revolutions, 
of which modern chemiftry may appreciate the caufe,, 
and of which, perhaps, it may fome clay foretel the final 
effects. 
DESCRIPTION of several new and valuable 
CHEMICAL MACHINES. 
Compound diftillation is one of the mod important 
operations in chemiftry. The fubftance which is fepa¬ 
rated in every diftillation, comes over into the receiver in 
the form of gas. Now, if the nature of the gas be fuch, 
that by cooling alone it enters with facility into the li¬ 
quid ltate, a common receiver, fufficiently cooled, may 
be made ufe of for receiving this product; as, forex- 
ample, in the preparation of alcohol, diltilled vinegar. 
Sec. But, if the gafeous fluid cannot, by cooling alone,, 
be condenfed l'o as to become liquid ; or, if this change 
proceed very flowly, there is no other means of obtaining 
it in the lattter form, than to combine it, if poffible, with 
a greater or lefs quantity of water. Inftances of this kind 
are vtny frequent, as in the diftillation of nitric acid, of 
oxygeff^ted muriatic acid, caultic ammoniac, See. The 
means by which the ancient chemifts accomplifned this, 
end, confided in adding, in the retort, to the mixture to 
be diftilledfn^ much water as was neceffary to arreft the 
gafeous body which .had been difengaged. This water,, 
in confequence of the application of heat, being changed 
5 C into 
