534 On the two great powers, (Ocr. 
mentioned by Bertrnouter and Dr. Murray) are not the only forces 
which affect the solution. There are two others, which perhaps have 
quite as much influence on the extent of the combination ; namely, the 
repulsive force, operating between the atoms of the salt, and the re- 
pulsive force between these atoms, and those of water*. Itis this last 
force, which prevents the most perfect combination from ensuing. It 
has however, been shewn, under a former head, that if this force, (viz. 
the repulsive force operating between the solid and liquid) varied in 
the same ratio as their attraction, it certainly could not prevent the 
atoms of the former, from being brought into absolute contact, with 
those of the latter. 
But, admitting this repulsive force to vary in a higher inverse ratio 
of the distance, than the attraction, the nature cf the solution may be 
clearly explained in the following manner. 
It is plain, that the forces opposed to the solution, are the cohesion, 
the greater specific gravity of the solid, and that repulsive force which 
must operate between its atoms, and those of the water. That the 
forces favoring the solution, are the repulsive force operating between 
the atoms of the salt itself, and their affinity for those of the water. If 
when the salt is immersed in the water, the two latter forces united, 
are more powerful than the three former united, the water must begin 
to act on the salt. As the atoms of salt separate from each other, the 
repulsive force operating between them, which is one of the forces fa- 
voring the solution, at last loses its effect, owing to its varying ina 
greater inverse ratio of the distance than the cohesive attraction of the 
salt, and therefore becoming weaker than the cohesive attraction. 
Again, as the atoms of salt and water approach each other, the re- 
pulsive force operating between these two. bodies, though formerly 
much inferior to their affinity, owing to its varying in a higher ratio. 
becomes at last, at a certain point, equal to the affinity. And could the 
atoms of the salt be brought still nearer to those of the water, the re- 
pulsion for the same reason would grow superior to the affinity. It is 
manifest then, as the atoms of salt and. water cannot approach nearer 
to each other than the point, at which the two powers are equal, that 
the atoms must rest at this distance from each. other : for there the 
two forces form a stable equilibrium. 
And, since the atoms of liquids are endowed with greater atmospheres 
of heat, than those of solids, this superior repulsive force in them may 
* The repulsive force and attraction. operating between the atoms of the water 
themselves need not be mentioned: as the doctrine may be explained without tak- 
ing them into consideration. 
