228 Analyfts of the Air. 



( Frg. 35.) did in burning abforb much air 5 

 and it was the fame with Antimony and 

 Brimflone : Whence it is probable, that Vul- 

 cano'Sj whofe fewel confift chiefly of Brim* 

 Jione, mix'd with feveral mineral and mc- 

 taline fubftances, do not generate, but rather 

 abforb air. 



We find in the foregoing Experiment 102 

 on Nitre, that a great part of the new ge- 

 nerated air is in a few days reforbed, or 

 lofes its elafticity : But the air which is ab- 

 ibrbed by burning Brirnftone, or the flame 

 of a Candle, dees not recover its elafticity 

 again, at leaft, not while confined in my 

 glafTes, 



Experiment C V. 



I made feveral attempts to try, whether 

 air full of the fumes of burning Brim- 

 ftone was as compreflible as common frefh 

 air, by compreffing at the fame time tubes 

 full of each of thefe airs in the condenfing 

 engine ; and I found that clear air is very 

 little more compreflible, than air with fumes 

 of Brimflone in it : But I could not come to 

 an exaft certainty in the matter, becaufe the 



fumes 



