204 Analyfis of the Air. 
Experiment LXXXIII. 
In February •! poured on fix cubick Inches 
of powdered Oyfterfiell, an equal quantity 
of common white-wine Vinegar . In five or 
fix minutes it generated 17 cubick inches of 
air, and in fome hours iz cubick inches 
more 5 in all 29 inches. In nine days it 
had {lowly reforbed 2 1 cubick inches of air. 
The ninth day I poured warm water into 
the veffel xx, (Fig. 34.) and the following 
day, when all was cool, I found that it had 
reforbed the remaining 8 cubick inches. 
Hence we fee that warmth will fometimes 
promote a reforbing as well as a generating 
ftate, viz. by raifing the reforbing fumes*, 
as will appear more hereafter. 
Half a cubick inch of Oyfterjhell \ and a 
cubick inch of oil of Vitriol, generated 32 
cubick inches of air. 
Oyfterjhell , and 2 cubick inches of four 
Rennet , of a Calf's ftomach, generated in 
four days 1 1 cubick inches. But Oyfterjhell 
with fome of the liquor of a Calf s ftomach, 
which had fed much upon hay, did not ge- 
nerate air. It was the fame with Oyfterjhell 
and Ox-gall, Urine and Spittle* 
Half 
