PHYSICAL anv LITERARY. 167 
meter, is owing to the mixture of thefe 
with the water of the air; and therefore, 
it is ftill very probable, that all fluids, 
which do not immediately affeét the mix- 
ture of the air, will, in evaporating, pro 
‘ duce cold. | 
WHEN J had proceeded thus far, I be- 
gan toconfider, whether the cold produced 
in the above experiments might not be the 
effet of the mixture of the feveral fluids 
with the air; and that therefore, toa lift 
of cooling mixtures and folutions which 
I was then making up, I fhould now add 
the feveral folutions made by the air. By 
one who fuppofes the evaporation of fluids 
to depend upon the action of the air as a 
menftruum, this would be readily admit- 
ted; but, as I knew that fluids evaporate 
mm vacuo as well as in the air, 1 refolved to 
fufpend my opinion, till I fhould repeat 
my experiments in an exhaufted receiver. 
In profecuting thefe, a number of new, 
_and,to me, curious phenomena have prefent- 
ed themfelves; fo many, that I find the 
experiments muft be often repeated, and 
art diverfified, before I can give the 
pecety 
