1833. ] Attraction and Repulsion. 535 
cause the point of stable equilibrium, between the atoms of the solid and 
the fluid, to exist at a greater distance, than between the atoms of two 
solids when in combination, and hence the latter combinations are ge- 
nerally much more intimate than the former. 
The solution of solids in liquids and the weak resulting combination, 
are therefore satisfactorily explained by this doctrine ; which considers 
the force of repulsion from heat as varying in a greater inverse ratio 
than the attraction. 
Fifthly.—To the solution of liquids in' gases and in the atmosphere. 
Under a former head, I have endeavoured to prove, that the hygro- 
metric vapor of the atmosphere must exist in that state, partly by its 
own elasticity, and partly by an attraction exerted on it by theair. But 
it was also proved, that if the repulsion of atoms varies in the same 
ratio, as the ratio of attraction, the atoms of water would come into ac- 
tual contact with those of the air ; which cannot be the case, as hygro- 
metric vapor is in the very weakest state of combination with the air. 
The solution of vapors in gases, without an intimate combination ensu- 
ing, may however, I think, be readily explained by the present doctrine. 
o ° o 0 Let a liquid A be’ placed under a column of 
reeuttits sseesttttieee sth. dry air B, which is pressing on it with the 
usual force of the atmosphere. It is plain that 
the layer of air nearest the liquid must’ press on the latter with the 
whole force of the atmosphere which it supports. But the particles of air 
are far more distant fromeach other than those of water; probably 
ten times as far. Let us. suppose this to be their relative distance. 
Every tenth particle only of the liquid will be pressed on perpendicularly 
by the lower stratum of air; and the:condensation of the circumambient 
heat of this stratum will be so much greater perpendicularly under 
each particle of air, than obliquely between them, that it will re-act 
more upon the water directly under those particles, and press it into 
dimples, as in the figure: The ridges between these dimples will be 
pressed on laterally by the elastic medium of each aerial. particle, but 
with little force downwards. 
All the aerial particles above this lowest stratum must be ata great- 
er distance from those of the water, than the point at which the forces 
operating between them and the water, are equal. And, being at a great- 
er distance than this point, they must attract the water with more force 
than they repel it, according to the present postulate. If then the 
united effective attractions of all atoms of air above the lowest stratum, 
together with the tendency to expand in the water itself, be superior to 
the gravity of the atoms of water situated in the several ridges, the 
