ipi AnaVjfis of the Atr, 
means of fire and fermentation raifed from, ^ 
and abforbcd by animal, vegetable and mi- 
neral fubftances. 
That this air confifts of particles which are 
in a very a£liv*e ftate, repelling each other 
with force, and thereby conftituting the fame 
kind of elaftick fluid with common air, is 
plain from its raifuig the Mercury in Expe- 
riment 8 8 and 89, and from its continu-' 
ing in that elaftick ftate for many months, 
tho' cooled by fevere frofts 5 whereas watry 
vapours, tho' they expand much with heat, 
yet are found immediately to condenfe in- 
to their firft dimenfions when cold. 
The air generated by fire was not, in 
many inftances, feparated witl^out great vio- 
lence from the fix’d bodies, in which .it 
was incorporated 5 as in the cafe of Nitre-, 
Tartar^ SalTartar znA Copperas: whence it 
fhould feem, that the air generated from 
thefe Salts, may probably be very inftru- 
mental in the union of Salts, as well as that 
central, denfer and comparer particle of 
earth, which Sir Ifaac Newton obferves, 
docs by its attradion make the watry acid 
flow round it, for compofing the particles of 
Salt, qu, 31. For fince upon the diflblution 
of 
