2 24 Analyfis of the Air . 
Experiment XCVL 
April 1 6th, a cubick inch of the afore- 
mentioned Walton ^Pyrites powder’d, with 
a cubick inch of compound Aqua-fort is, ex- 
panded 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, arid then abforbed 85 cubick inches 
of air. 
But the like quantity of the fame Mine- 
ral, with equal quantities of compound Aqua- 
fortis and Water , fermented more violently 
and generated above 80 cubick inches of air. 
I repeated thefe Experiments feveral times, 
both with and without water, and found 
conftantly the fame effed. Yet Oil of Vi- 
triol 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. 
Experiment XCVII, 
a I 
I chofe two equal fized boltheads, and 
put into each of them a cubick inch of 
powdered 
