Analyfts of the Air. 293 
of the conftituent parts of Salt by fire, it is 
found, that upon feparating and volatilizing 
the acid fpirit, the air particles do in great 
abunjdance rulh forth from a fixt to a re- 
pelling elaftick ftate 5 it muft needs be, that 
thefe particles did in their fixt ftate ftrongly 
attrad the acid fpirits, as well as the ful- 
phureous earthy parts of the Salt j for the 
moft ftrongly repelling and elaftick parti- 
cles are obferved, in a fixt ftate, to be the 
moft ftrongly attrading. 
But the watry acid, which when feparated 
from Salt by the adion of fire, makes a very 
corrofive fuming fpirit, will not make elaf- 
tick air, tho’ its parts were put into a brisk 
motion by fire in Exper. 75. And the event 
was the fame with feveral other volatile 
fubftances, as volatile Salt of Sal Ammont- 
Camphire and Brandy^ which tho’ di- 
ftilled over with a confiderable heat, yet 
generated no elaftick air, in Exper. 52, 61^ 
66. Whence 'tis plain, the acid vapours in 
the air only float in it like the watry va- 
pours 5 and when ftrongly attraded by the 
elaftick particles of the air, they firmly ad- 
here to them, and make Salts. 
U a 
Thus 
