18 ON ADIPOCIRE, AND ITS FORMATION. 
p- 1072,) stearic acid is C,,, H,,, O,, and the magnesia salt contains by calculation, 6-9 per 
cent. of that base. The foregoing experiments upon the two specimens of human adipocire 
were intended preliminary to a more thorough research into their nature, by Heintz’s 
method; but this process requires such a large quantity of substance in order to effect the 
separation of small quantities of whatever new acid might be present, and the amount of 
material dwindled so in the many necessary crystallizations from alcohol to separate the 
dark-coloured impurities, and especially, since the determinations and reactions already 
made, were so confirmatory of what has lately been done in working upon the solid fatty 
acids, I preferred placing aside the substances thus obtained for a future examination, 
when the separation of fatty acids shall have become more simplified, as it must be before 
long. 
(c) Fossil adipocire of Bison Americanus obtained from a metacarpal bone from Big Bone 
Lick, by Dr. Leidy.—It was a white powder, and in pulverizable lumps; amorphous 
under the microscope; with a talcose feel, and of density a little below 0°8365, since it 
barely swims upon alcohol of that strength, while it sinks in absolute alcohol. Water will 
not wet it; with the addition of hydrochloric acid and heat, it is separated without effer- 
vescence, into a mineral solution, and into an oil which solidifies on cooling to a nearly 
white fat, a small portion of which melted on a glass slide solidifies to a confusedly crys- 
talline mass; a small quantity treated in the same way with absolute alcohol, crystallizes 
in plumose and dendritic crystals, like margaric acid. A portion of the adipocire boiled 
with absolute alcohol, yields but a minute quantity to the solvent, and that not of a fatty 
nature, showing that the fatty acid is wholly saponified with an earthy base. The whole 
quantity of adipocire weighed 0-986 grammes. 0:16325 heated in a platinum crucible, 
fuses, burning with a smoky flame and with the smell of fatty acid, but no acroleine, 
leaving 0:0165 or 10:1 per cent. of a perfectly white ash, which hydrochloric acid almost 
perfectly dissolves without effervescence, and which consists almost entirely of lime, with 
a few minute specks of oxide of iron (seen during the action of the hydrochloric acid,) and 
a couple of small grains of sand: there is a very small trace of phosphoric acid present. 
The greater portion of the adipocire, 0716 grammes, was decomposed by hydrochloric acid 
and water, by the aid of heat: the decomposition took place with a strong smell of rancid 
tallow, and the fundamental smell observed in all adipocire was emitted. It was melted 
and washed several times, at first with acidulated and finally with pure water. The water 
from the washing, when evaporated, gave a certain quantity of brownish yellow colouring 
matter. The fat was melted in the capsule in which the precipitation took place, and 
weighed 0:618 or 86:31 per cent. of the adipocire; when melted, a dark flocculent humus- 
like precipitate was seen; the fat itself was yellowish, and of a flat, waxy (here and there 
warty) surface. It melted at 51°. 
