C 159 ], 
Seventhly ; If into any menflruum v^re throw a 
body, which it diffolves, and afterwards add another, 
to which the menftruum has a greater affinity than 
it has to the firft, it will diffiolve the fecond body, 
and let go the firft, which will be precipitated and 
fall to the bottom. In like manner, if to well rec- 
tified fpirit of wine, we add an equal quantity of 
clear rain, or river water, thefe fluids (which incor- 
porate fo readily) having a greater affinity to each 
other than to the air they contain, will let go ai 
great part of the air, which will rife to the top, or 
ftick in fmall bubbles to the bottom and fides of the 
veftel ; from whence I infer, that air is contained in 
thefe fluids in the fame manner that the particles of a 
body are contained in a menftruum that diflblves it ; , 
and, therefore, that the air imbibed by thefe fluids, is pro- 
perly fpeaking, diflblved in them, and confequently 
that any fluid which evaporates, or is imbibed by the 
air, is alfo, properly fpeaking, diflblved in air. And 
upon this principle we may fay, that water is drawn 
out of the air, by dry fait of tartar, from its having 
a greater affinity to that fait than to the air. 
1 ihould not have been fo tedious, in comparing, 
together the natures of folution and evaporation, in . 
fo many inftancos, but that it gave me an opportu- 
nity, at the fame time, of explaining fome of the. 
phenomena that 1 at firft intended to confider ; , 
which explanations, I believe, will be admitted, if; 
li am right in the mean point, I have endeavoured ; 
to prove. And really when we confider how exactly 
folution and evaporation agree in their feveral ap- 
pearances, properties, and effedts, I think we may 
be convinced that they are natural operations of 
