from each other.

It is, perhaps, more natural to suppose, that the particles of caloric
have a stronger mutual attraction than those of any other substance, and
that these latter particles are forced asunder in consequence of this
superior attraction between the particles of the caloric, which forces
them between the particles of other bodies, that they may be able to
reunite with each other. We have somewhat analogous to this idea in the
phenomena which occur when a dry sponge is dipt into water: The sponge
swells; its particles separate from each other; and all its intervals
are filled up by the water. It is evident, that the sponge, in the act
of swelling, has acquired a greater capacity for containing water than
it had when dry. But we cannot certainly maintain, that the introduction
of water between the particles of the sponge has endowed them with a
repulsive power, which tends to separate them from each other; on the
contrary, the whole phenomena are produced by means of attractive
powers; and these are, _first_, The gravity of the water, and the power
which it exerts on every side, in common with all other fluids; _2dly_,
The force of attraction which takes place between the particles of the
water, causing them to unite together; _3dly_, The mutual attraction of
the particles of the sponge with each other; and, _lastly_, The
reciprocal attraction which exists between the particles of the sponge
and those of the water. It is easy to understand, that the explanation
of this fact depends upon properly appreciating the intensity of, and
connection between, these several powers. It is probable, that the
separation of the particles of bodies, occasioned by caloric, depends in
a similar manner upon a certain combination of different attractive
powers, which, in conformity with the imperfection of our knowledge, we
endeavour to express by saying, that caloric communicates a power of
repulsion to the particles of bodies.

FOOTNOTES:

[2] Whenever the degree of heat occurs in this work, it is stated by the
author according to Reaumur's scale. The degrees within brackets are the
correspondent degrees of Fahrenheit's scale, added by the translator. E.

[3] Collections of the French Academy of Sciences for that year, p. 420.

[4] Chemical Nomenclature.

[5] As I shall afterwards give a definition, and explain the properties
of the liquor called _ether_, I shall only premise here, that it is a
very volatile inflammabl