Jrom Water and cther Liquids, e. 573 
212°; then the space — ee —= 23 or water 
o—30 
under the pressure of 60 inches of mercury, and 
at the temperature of 212°, produces vapour 
which just doubles the se ie of air. 
If ether be the instance: let the temperature 
be equal 70°; then f — 15; and suppose 
f = 30; in this case the colume of air is doubled ; 
that is, ether of 70° being admitted to any por- 
tion of air, dcubles its bulk. 
The expansion of hydrogenous gas and atmos- 
pheric air by the vapour of water is the same 
for every temperature. 
Sulphuric acid does not expand atmospheric 
air to any sensible amount by the heat of boiling 
water. 
The theory of these facts is evident upon the 
Principles laid down in the former essay: for 
instance ; let it be required to explain the expe. 
riment with water of 212° under a pressure of 
60 inches. Here the air was condensed into the 
space 1 by the pressure of 60 inches; but being 
exposed to water of 212° a vapour arose from it 
equal in force ta go inches; the air therefore ex- 
panded tll its force also became = to 30 inches, 
which was effected by doubling its volume: then 
the vapour pressing with 30 inches force and the 
air also with 30 inches force, the two together 
support the pressure of 60 inches and the equi- 
. 
