410 Dr, Crawford’s Experiments on the Matter 
parts of pure air being mixed with one of animal air, occupied .8 
©fan inch. The mixture being fired by the ele&rical fhock, the 
refid ue {food at a little lefs than .5. When this refidue was agi- 
tated with lime-water, it was almoft wholly abforbed. By afub- 
fequent trial it was found, that nearly one-half of the animal 
air ufed in this experiment was foluble in water. 
Hence it appears, that the quantity of pure air required to fa- 
turate the infoluble part of the animal air is fomewhat lefs than 
that required to faturate the compound fluid which had not been 
previoufly agitated with water. But the latter fluid has been 
ihewn to confift almoft entirely of heavy inflammable, animal 
hepatic, and fixed air; and as the laft of thefe is already fatu- 
rated with pure air, it is manifeft, that the above-mentioned 
difference muft depend upon the animal hepatic air. Whence it 
follows, that the latter contains a large portion of the inflam- 
mable principle. From the quantity of fixed air produced in 
the laft of the preceding experiments, there is, moreover, the 
utmoft reafon to believe, that the bafis of heavy inflammable 
forms one of the conftituent parts of animal hepatic air. 
When equal parts of pure and animal air were burned toge- 
ther, a confiderable increaic of bulk almoft invariably took 
place; and when the proportion of the animal was to that of 
pure air as 21 to 15, the bulk of the mixture was increafed 
one half. The air that remained after the combuftion in the 
laft mentioned experiments was inflammable : for a portion of 
it being introduced into a fmall phial, and expofed to a lighted 
candle, it firft exploded, and then burned with a blue lambent 
flame. 
Being defirous of learning the caufe of the increafe of bulk 
in the foregoing experiments, the following trials were made. 
, “ Three 
