i66 Analyfis of the Ah\ 
Air; and this Air by fermentation, and 
fometimes without it, returns into denfe 
bodies.’* Of the truth of which we have 
evident proof from many of the following 
Experiments, viz. 
That I might be well affured that no part 
of the new Air which was produced in di- 
ftillation of bodies, arofe either from the 
greatly heated Air in the retorts, or from 
the fubftance of the heated retorts, I firft 
gave a red hot heat both to an empty glafs 
retort, and alfo to an iron retort made of a 
musket barrel ; when all was cold, I found 
the Air took up no more room- than be- 
fore it was heated : whence I was affured, 
that no Air arofe, either from the fubftance 
of the retorts, or from the heated Air. 
As to animal fubftances, a very confide- 
rable quantity of permanent Air was pro- 
duced by diftillation, not only from the 
blood and fat, but alfo from the moft folid 
parts of animals. 
Experiment XLIX. 
A cubick inch of Hog*s bloody diftilled to 
dry fcoria, produced thirty three cubick 
inches 
