Analyfn of the Air. 225 



powdered Walton Pyrites, with only a cu- 

 bick inch of compound Aqua-fortis into one, 

 and a cubick inch of Water and compound 

 Aqua-fortis into the other : Upon weighing 

 all the ingredients and veflels exaftly, both 

 before and after the fermentation, I found 

 the bolthead with compound Aqua-fortis alone 

 had loft in fumes 1 dram 5 grains : But the 

 other bolthead with Water and compound 

 Aqua-fortis, which fumed much more, had 

 loft 7 drams, 1 fcruple, 7 grains, which is 

 fix times as much as the other loft. 



Experiment XCVIIL 

 A cubick inch of Newcajik Coal pow- 

 dered, and an equal quantity of compound 

 Aqua fort is poured on it, did in three days 

 abforb 18 cubick inches of air; and in 3 

 days more it remitted and generated 12 cu- 

 bick inches of air; and on pouring warm 

 Water into the veflel x x, (Fig. 34.) it re- 

 mitted all that had been abforbed. 



Equal quantities of Brimjione and com- 

 pound Aqua-fortis neither generated nor ab- 

 forbed any air, notwithstanding hot Water 

 was poured into the veffel x x. 



A cubick inch of finely powdered Flint, 

 and an equal quantify of compound Aqua- 



Q_ j- 



