Anal^fts of the Air. 301 
.abforbs elaftick air vigoroufly : As may be 
feen in many inftances under Experiment 95. 
The Walton mineral, in which there is a 
good quantity of fulphur, did, when Com- 
pound Aquafortis was pour’d on it, in Ex- 
periment 96, make a confiderable fermen- 
tation, and abforb a great quantity of elaftick 
air: But when the ferment was much in- 
creafed, by adding an equal quantity of 
water to the like mixture, then inftead of 
abforbing 85 cubick inches as before, it 
generated 80 cubick inches of air ; So that 
fermenting mixtures, which have fulphur in 
them, do not always abforb, but fometimes 
generate air : The reafon of which in the 
Experiment now under confideration feems 
to be this, viz, in the firft cafe a good quan- 
tity of. elaftick air was generated, by the 
inteftine motion of the fermenting ingre- 
dients ; but there arifing thence a thick, acid 
fulphureous fume, this fume abforbed a 
greater quantity of elaftick air than was be- 
fore generated : And we find by Experiment 
105 that the fulphureous particles which fly 
olFih the air, do by their attraftion deftroy its 
elafticity 5 for in that Experiment burning 
Brimftone greatly deftroy ed theaifs elafticity 5 
I which 
