ef Cancer , and on Animal Hepatic Air. 421 
fioned a copious precipitate in lime-water ; it was highly in- 
flammable, and burned with a blue lambent flame. 
The piece, on the contrary, which was expofed to the com- 
mon air, did not, as has been already obferved, fo foon lofe its 
fibrous texture, nor fo y fpeedily acquire a dark colour, as that 
which was in contadt with the animal air. But the progrefs 
of its putrefaction did not appear to flop at the end of a few 
days, as in the latter inftance. It advanced flowly, and at the 
expiration of fix weeks a confiderable part of the rnufcular 
fibres had run down to a brown liquid. The air in which it 
was placed now occafioned a copious precipitation in lime- 
water, and the brown liquid was found to be impregnated with 
animal hepatic and fixed air ; the exiftence of the latter being 
known by means of lime-water, and that of the former by 
its occafioning a dark precipitate in a folution of nitrated filver, 
as well as by its fetid odour, which was increafed by the vitri- 
olic, and defcroyed by the concentrated nitrous and dephlogifti- 
cated marine acids* 
The following experiment was made with a view to deter- 
mine whether pure air accelerates the progrefs of putrefadtion> 
in animal fubftances. , 
In the month of December, 1789, equal portions of pure 
and of common air were introduced into two equal jars over 
mercury, in each of which was placed about two drams of 
frefh beef. At the end of a week, the beef which was expofed to 
the pure air had become highly putrid ;, but very little change 
was produced in that which was expofed to the common air. 
The fadts which have been afcertained by the preceding 
experiments, appear to lead to the following conclufions refpedt- 
ing the procefs of putrefadtion in the lean of animal fub- 
ftances. 
6 , 
The 
