Anatyfis of the Air. zyj 



quently thofe fubftances fhould take fire, 

 and burn for a ftiqrt time at leaft, which yet 

 they did not. 



And that the air's elafticity conduces much 

 to the intenfe burning of Fires, feems evident 

 from hence 5 that Spirit of Nitre (which 

 by Experiment 75 has but little elaftick air 

 in it) when poured upon live Coals, ex- 

 tinguiflies inftead of invigorating them : 

 But Spirit of Nitre \ when by being mixt with 

 Sal Tartar it is reduced to Nitre, will then 

 flame, when thrown into the Fire, viz. be- 

 caufe Sal Tartar abounds with elaftick aereal 

 particles, as appears by Experiment 74, where 

 224 times its bulk of air arqfe from a quan- 

 tity of Sal Tartar. And for the fame reafon 

 it is that common Nitre, when thrown into 

 the Fire, flames, tho' its Spirit will not, viz. 

 becaufe there is much elaftick air in it, as 

 appears from Experiment 72, as well as from 

 the great quantity of it, generated in the 

 firing of Gun-powder. 



The reafon why Sal Tartar, when thrown 

 on live Coals, does not detonize and flame 

 like Nitre, (notwithftanding by Experiment 

 74 plenty of elaftick particles did arife from 

 it) is this, viz. becaufe by the fame Expert 

 T | mcnt, 



