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quantity than cold water j and if a ftrong folution"of 
lalt be made in hot water, the water, when cold, will 
let go fome of the fait before diffolved, which will 
fall to the bottom in fmall particles, or flaoot into 
cryftals. Juft fo will water evaporate fafter in warm 
than in cold air 3 and the aqueous vapours, fufpended 
in the air during the heat of the day, fall down at 
night, and form themfelves into drops of dew ; or, if 
the night be very cold, appear next morning in a 
hoar~fro(i. And thus, if in a hot day, a bottle be 
filled with any very cold liquor, and expofed to the 
air, which to us feems very dry, a dew will be foon 
formed on the outfide of the bottle j for the air about 
it, becoming cold, will let go part of its moifture, 
which will be attracted to the furface of the s;lafs. 
And, for the fame reafon, a dew is formed on the 
in fide of the windows of a warm room, which on 
their outfide are expofed to thecold.air*. And hence 
vve may obferve, that, as there cannot be fb conti- 
nual and copious an evaporation in cold weather, the 
air will then be generally clearer than it is in hot 
w’eather. 
Heat feems to promote folution, becaufe it expands 
bodies, and thereby enlarges their pores, and leflens 
the cohefive attraiftion of their particles, fo that a 
body when hot will more eafily admit a diftblving 
fluid into its pores, and its particles not cohering to- 
gether fo ftrongly, as when cold, will more readily 
quit each other, and unite themfelves to the particles 
of the fluid by which they are attracted j and for the 
fame reafon heat will alfo promote the evaporation of 
fluids.. ~ 
But 
