2 8 6 Anatyfis of the Air. 
ing Experiments, that acid fulphureous fuel 
conftantiy attracts and condenfes a confide- 
rablepartof the circumambient elaftick air; 
An argument, that there is no fire endued 
with peculiar properties inherent infulphur • 
and alfo that the heat of fire confifls princi- 
pally in the brisk vibrating adion and re- 
adion, between the elaftick repelling air, and 
the ftrongly attrading acid fulphur, which 
fulphur in its Analyfis is found to contain 
an inflammable oil, and acid fair, a very fix’d 
earth, and a little metal. 
Now fulphur and air are fuppofed to be 
aded by that ethereal medium, “ by which 
(the great Sir Ifaac Newton fuppofes) 
“ light is refraded and refleded, and by 
* c whofe vibrations light communicates heat 
“ to bodies, and is put into fits of eafy 
<c refledion, and cafy tranfmiflion : And 
do not the vibrations of this medium 
“ in hot bodies contribute to the intenfe- 
u nefs and duration of their heat? And do 
not hot bodies communicate their heat 
to contiguous cold ones, by the vibra- 
€< tions of this medium, propagated from 
them into cold ones ? And is not this 
cc medium exceedingly more rare and fub- 
“ tie than the air, and exceedingly more 
€G elaftick 
