When the principle of attraction prevails, it causes them to become solid; when caloric prevails, they become aeriform. Fluidity is, apparently, a medium between the two.
How is the state of Solidity in bodies accounted for?
The particles of all bodies are subject to two opposite powers, repulsion and attraction; between which they remain in equilibrium. While the attractive force remains strongest, the body remains in a state of solidity; but if heat destroys this force, the particles lose their cohesion, and the body ceases to be solid.
Cohesion, act of sticking together, union of the constituent parts of a body.
Which is supposed to be the most natural state of all bodies?
Solidity; for by the combination of caloric with them we can reduce most substances to the fluid state; while the greatest number of liquid substances take a solid form by the loss of caloric. Thus, water congeals and forms ice; and even the gases show this disposition to become solid, when they lose their elasticity by forming some combination.
Explain the terms Repulsion and Attraction.
Repulsion is a peculiar property in the particles of matter, which gives them a constant tendency to recede from each other. Attraction is an unknown force, which causes bodies or their particles to approach each other. The particles of all bodies possess this property, which causes them to adhere, and preserves the various substances around us from falling in pieces.
What different kinds of Attraction can you mention?
Attraction may be distinguished into that which takes place between bodies at sensible distances, and that which manifests itself between the particles of matter at insensible distances.