CHEMISTRY. 
361 
general. La Grange has fome experiments on this 
fubjett, printed in the 37th vol. of the Journal de Phy- 
fique. “ That which fucceeded belt,” (ays he, “ was to 
curdle milk by the ele6tric fluid, and then reltore it to 
its priftine ftate by means of a pure alkali. This milk 
was as mild, as white, and as creamy, as when drawn 
from the animal: but to curdle it again, required fix 
times as much acid, or eleftric fluid, as at firit.” 
The concentrated acids likewife diflolve cheefe; nitric 
acid difengages azotic gas; but the vegetable acids do 
not fenlibly diffolve it. Its folution in the mineral acids 
is precipitated by the alkalis, which re-difl'olve it if added 
in too great a quantity. The neutral lalts, more parti¬ 
cularly muriat of foda, retard its putrefa&ion. Alcohol 
coagulates it. P’rom all thefe fafts it appears, that cheefe 
is a fubftance greatly refembling the albumen of the 
blood. 
Of Butter. —The manner of making butter varies 
according to the materials employed. For good frefli 
butter, a certain quantity of the ferous and caleous mat¬ 
ter Ihould be retained. Butter is of a loft confiftence, of 
a yellow more or lefs inclining to the colour of gold, and 
of a mild pleafant tafte. If butter incloled in a glafs tube 
be heated, its three parts will be feparated, the butyrous 
or yellow, the ferous, and the caleous. 
Butter in melting approaches to the ftate of fat, not 
of oil, as has been faid: its conftituent parts are a proof 
of it. At the fame time the albuminous part is feparated, 
and it becomes yellower. It may be coloured by the 
juice of winter-cherries, carrots, faffron, orcanet, fpinage, 
tin&ure of violets, &c. Butter melts by a gentle heat; 
when congealed, it cryftallizes and becomes granulated, 
having a particular tafte and fmell. If left long upon 
the fire, its acid it developed. Diftilled with a naked fire, 
hydrogen is difengaged, which, with the oxygen of the 
atmofpheric air forms water. By keeping up the heat, 
it furnifhes a very ftrong and pungent acid of a penetrat¬ 
ing fmell; this is febacic acid. ; a fluid oil, and afterwards 
a concrete coloured oil of a ftrong fmell, and fome car¬ 
bonated hydrogen gas. The remaining coal is not abun¬ 
dant ; it contains very little laline matter; a little alkaline 
matter and calcareous phofphatmay be extra&ed from it. 
Butter foon becomes four and rancid in a warm air; 
by wafhing and fhaking it may be in fome meafure re- 
ftored, but never completely. The w’ater will afterwards 
redden the blue vegetable colours. The carbonic acid 
turns butter of a brown colour. Alkalis diffoive it; and 
thus very good foaps might be made. Muriat of foda 
lias the property of keeping butter fweet, by abforbing 
the water from the atmofphere, and preventing it from 
combining with the butter. 
Properties of different Kinds of Milk.— 
Woman’s milk will not furnifh butter. The milk offheep, 
cows, goats, and women, has a very thick cream. Cream 
from the milk of women, mares, and afles, never can be 
made into butter. The cafeous matter is fcarcely coagu- 
lable in fheep’s milk, but very eafily in that of cows and 
goats. The ferum is very plentiful in the milk of wo¬ 
men, mares, and afles; lefs fo in that of cows and goats, 
and leaft of all in (heep. The proportions, according to 
Hoffman, Parmentier, and Deyeux, are as follow : In 
Iheep, o - i 5 ; goats, o - 20; women, C27; mares, C30 ; 
afles, 0-35. 
Haller has given the following proportions of the fugar 
contained in the milk of different animals 1 : 
Four ounces of Iheep’s milk afforded of 
Sugar of milk, 
Goat’s milk afforded 
Cow’s milk, 
Human milk, 
Mare’s milk, 
Afs’s milk. 
- 
- 
35 or 
37 grains. 
- 
- 
47 — 
49 
- 
- 
53 — 
54 
- 
- 
58 — 
67 
- 
- 
69 — 
70 
- 
- 
80 — 
82 
Rouelle has obferved, that the whey of cow’s milk, 
from which the fugar of milk has been extracted, takes 
Vol. IV. No. aoj. 
the form of jelly by cooling 5 and he confequently admits 
it to contain gelatinous matter. 
Milk is an agreeable food, of confiderable ufe in a 
great number of cafes; it is even one of the moll valu¬ 
able medicines we poffefs. It correfts the acrid humours 
in diforders of the fkin, and of the articulations. It ci- 
catril'es-ulcers of a good kind. It may be charged with, 
the aromatic parts of plants, and is then an excellent re¬ 
medy in the pulmonary confumption. All ftomachs, 
however, do not digeft milk. Such perfons as are inclined 
to acidities in the firft paflages, are ufually incommoded 
by it; and in general it ought to be adminiftered pru¬ 
dently. Milk, rendered medicinal, by caufing the animal 
which gives it to take different fubftances, is often ufed 
with fuccefs in various diforders. 
The millc-of different animals has certain peculiar 
virtues. That of the human fpecies is mild, of afaccliarine 
tafte, and is greatly ferviceable in the marafmus. The 
milk of the afs is l'uccefsfully ufed in the pulmonary con¬ 
fumption and the gout; it ufually relaxes. Mare’s milk 
relembles that of the afs. Goat’s milk is ferous, and 
lightly aftringent. Cow’s milk is the-thickeft, the fatteft, 
and the moft nourilhing; it is likewife the moft difficult 
of digeftion, and often requires to be diluted with water, 
or with fome aromatic infufion, efpecially if it does not 
eafily pafs off, or produces coftivenefs. Milk is likewife 
ufed externally, as a loftening and emollient remedy. It 
mitigates pain, ripens gatherings and abfcelfes, and haf~ 
tens fuppuration. It is applied hot, and enclofed in a. 
bladder on the dilealed parts. 
Of BILE. 
The bile, or gall, is a fluid feparated in thatglJndulous 
vifcera called the liver. The nearer the bile lies to the 
ftomach, the more the animal eats. The bile, when fe¬ 
parated, is collefted in the gall-bladder, and thence goes 
to the duodenum. The horfe and flag have no gall-blad¬ 
der ; but it is never wanting in birds and fillies: moft ani¬ 
mals have it, except infedls and worms. The bile is of 
a green colour inclining to yellow, bitter in tafte, and 
of a glutinous, or almoft gelatinous, confiftence; it pours 
out like fyrup; and by agitation it lathers like foap-wa- 
ter. It will take out fpots of greafe. 
When diftilled in the water-bath, it affords a phlegm, 
which is neither acid nor alkaline, but after a certain time 
putrefies. This phlegm often exhibits a lingular charac¬ 
ter ; it emits an odoriferous fmell, of confiderable ftrength, 
and greatly refembles that of mufk or amber. Fourcroy 
thinks it might be ufeful in perfumery. When all the 
water which bile affords in the water-bath has been dif¬ 
tilled off, the refidue has the form of an extract, more or 
lefs dry, and of a deep and brownifh green. This extradl 
of bile attrafts the humidity of the air, is very tenacious 
and pitchy, and is totally foluble in water; by diftilling 
it in a retort, it affords a yellowifh and alkaline phlegm, 
an empyreumatic animal oil, much ammoniacal carbo- 
nat, and an elaftic fluid, confiding of a mixture of car¬ 
bonic acid and hydrogen gas ; after this operation, a coal 
remains of confiderable bulk, and lefs difficult to incine¬ 
rate than thofe we have hitherto fpoken of. According 
to Cadet, who communicated a very valuable memoir, on 
the analyfis of bile, to the Royal Academy, this coal 
contains carbonat of foda, an animal earth, and a final! 
portion of iron. By flow diftillation, it affords febacic 
acid and Prufiic acid, much more than other animal fub¬ 
ftances, carbonat, febat, and prufliat, of ammoniac. A 
denfe heavy coal remains, difficult of incineration ; but, 
when reduced to allies, calcareous phofphat and fulphat 
of foda may be obtained by lixiviation. Expofed to a 
temperature between fixty-five and eighty-five degrees, it 
quickly changes, its fmell becomes more naufeous, its 
colour is deftroyed, whitifh mucilaginous flakes are preci¬ 
pitated, its vifcidity difappears, and its fmell foon becomes 
fetid and penetrating. When the putrefaftion is in an 
advanced ftate, its fmell becomes fweet, and refembles 
4 Z amber, 
