xa4 AnaJyJis of the Air. 



Experiment XCVI. 



'April 1 6th, a cubick inch of the afore- 

 mentioned Walton Pyrites powder'd, with a 

 cubick inch of 'compound Aqua-fortis, expanded 

 with great violence, heat and fume into a fpace 

 equal to 200 cubick inches, and in a little time 

 it condenfed into its former fpace, and then 

 abforbed 85 cubick inches of air. 



But the like quantity of the fame Miner -al 9 

 with equal quantities oi compound Aqua-fort is 

 and Water \ fermented more violently, and ge-% 

 nerated above 80 cubick inches of air. 



I repeated thefe Experiments feveral times, 

 both with and without water, and found con- 

 ftantly the fame effedt. Yet Oil of Vitriol 

 and Water, with fome of the fame Mineral, 

 abforbed air. It was very warm, but did not 

 make a great ebullition. 



But this Walton Mineral, with equal quan- 

 tities of fpirit of nitre and water, generated 

 air, which air would abforb frefh admitted 

 air. See Vol. \l. p. 283, 292. 



Experiment XCVII. 



I chofe two equal-fi~ed boltheads, and 

 put into each of them a cubick inch of 



powdered 



