of Cancer , and on Animal Hepatic Air . 41 c 
Three meafures of animal were mixed with two of pure air, 
and feveral ftrong electrical (hocks were made to pafs through 
the mixture, but it would not take fire. Half a meafure of 
pure air was then added, and the mixture being fired, its bulk 
was encreafed from .9 of an inch to 1 inch and .3. 
Three meafures of this refiduary air were then mixed with 
three of pure air, and fired by the eledric fhock. *1 he bulk of 
the mixture was reduced from 1 inch to .56. This being agi- 
tated with lime-water, twO'thirds were abforbed, and the re- 
mainder confided almoft wholly of pure air* From thefe fads 
it feems probable, that animal hepatic air confifts of a combi- 
nation of heavy and light inflammable air ; and tnat when it 
is fired with a quantity of pure air not fufflcient to faturate it, 
a portion of the animal air is refolved into its elementary prin- 
ciples, in confequence of which its bulk is encreafed. 
It was before obferved, that three parts of animal mixed 
with two of pure air would not take fire. I11 fome ex- 
periments it was found, that when the animal air was 
mixed with a ftill fmaller proportion of pure air, an increafe 
of bulk was produced by the eledric fhock, although no 
deflagration took place ; but when the eledric fhock wa$ 
repeatedly taken through animal air alone , it did not in any 
inftance, as far as I could perceive, produce the fmalleft increafe 
of lize* 
I was next defirous of learning whether an increafe of fize 
would be produced by making the eledric fhock pafs through 
a mixture of pure and alkaline air. Having firft accidentally 
taken two or three fmall fhocks through a little alkaline air, 
and not obferving a fenfible augmentation of bulk, I then 
mixed it with an equal volume of pure air ; and, as I fuppofed 
that no decompofition had taken place, I was not apprehenfive 
H h h 2 of 
