[ 170 ] 
find, by experience, that the heat and cold, which 
we feel, does not either fo much rarefy, or lb much 
condenfe the air, but that the former may fiiil in- 
creafe, and the latter lefien the evaporation of fluids. 
Nor, indeed, does the Ifate of the atmofphere in 
general, as to rarity and denfity, depend upon the 
heat or cold we experience here below. Thefe 
caufes, therefore, according as they take place, in 
different degrees, will occafion thofe various fiates 
of the atmofphere, in refpedt to drynefs or moiflure, 
which we experience in the feveral changes of the 
weather. To which the winds contribute very much 
by heating or cooling, condenfing or rarefying, the 
different parts of the atmofphere ; and, by pro- 
moting the folution of water in air, as they mix 
thofe two fluids together, or when the air is already 
faturated with aqueous vapours, by prefiing together 
the particles in the clouds, and thereby caufing them 
to run into drops. And thus, from the knownproper- 
ties of folution, we may account in a fatisfad:ory 
manner for the afcent and circulation of aqueous 
vapours, and the feveral phasnomena of the atmo- 
fphere arifing from thence, which is a great confir- 
mation of the argument brought to prove that eva- 
poration is only a particular fpecics of folution * j 
■* Some time after this efTay had been read at a meeting of 
the Royal Society, the author was informed that the Abbe 
Nollet (to whofe works he was then an entire ftranger) had con- 
fidered evaporation as a kind of folution; and, having lately look- 
ed into his leftures, he finds the Abbe offers it as a conjecture, 
that the air may perform the office of a folvent and a fpunge in 
regard to the bodies it touches ; but this he does not prove, 
nor does he afterwards apply this principle of folution, in ac- 
counting for feveral phzenomena that depend on the nature of 
4 and, 
