Anal^fis of the Air. 215 
hours to generate 82 cubick inches of air 
more; but the following night being very* 
cold, little was generated : So the next morn- 
ing I poured hot water into the vcflel x x> 
which renewed the ferment, fo that it ge- 
nerated 4 cubick inches more, in all 130 cu- 
bick inches, a quantity equal to 520 times 
the bulk of the Antimony ^ 
The fermented mafs looked like Brim- 
ftone, and when heated over the fire, there 
fublimed into the neck of the bolthead a 
led fulphur, and below it a yellow, which 
fulphur, as Mr. Bojle obferves, Vol. III. 
f. 272. cannot be obtained by the bare ac- 
tion of fire, without being firfi well digefted 
in oil of Vitriol, or fpirit of Nitre. And by 
comparing the quantity of air obtained by 
fermentation in this Experiment, with the 
quantity obtained by the force of fire in 
Exper. 69. we find that five times more air 
was generated by fermentation than by fire, 
which (hews fermentation to be a more fub- 
tile diflblvent than fire 5 yet in fome cafes 
there is more air generated by fire than by 
fermentation. 
Half a cubick inch of oil of Antimony^ 
with an equal quantity of compound Aqua- 
P 4 fortis^ 
