ugh held together
by a decreased attractive power. In this condition we now say that it is
in the molten state. Now during all this time, what has the Aether been
doing, or what part has it played in the expansion and changing of the
solid to a liquid? We have to remember, from Art. 60, that wherever
there is motion of any kind or sort, there we have a capacity to do
work, and that the aetherial motion which we term heat is no exception
to this rule. We are now no longer dealing with a frictionless medium,
but with a medium which possesses weight, because it is gravitative, and
consequently possesses inertia also. So that whenever the Aether is set
in motion by flame or heat, its motion would be transmitted by waves of
some kind to the iron ball. These periodic waves, acting upon the mass
of the ball, attack the molecules of the ball and begin to set them in
motion. It is supposed that they are already in motion, as nothing is
absolutely cold, and the motion of the aetherial waves imparts a greater
motion still to the molecules, with the result that the agitation
becomes greater and greater, until at length the agitation becomes so
great, that the molecules break away from the power of attraction that
holds them together, and so begin to move about with greater freedom and
with greater rapidity. It is this state which we call molten. Now if
Aether be frictionless, as has hitherto been supposed, and if heat be
due to the vibratory motions of Aether, the problem confronts us, as to
how the motion of a frictionless medium can do work in expanding a body,
and urging the molecules of a body further and further apart. If the
Aether be frictionless, then the waves of Aether known as aetherial heat
waves ought to pass between the atoms as water passes through a sieve,
or wind passes through a forest. Yet it is assumed that the vibratory
motions of a hot body are caused by vibrations of the periodic waves of
the Aether, which act upon the molecules of the body; and, in order for
such an assumption to be consistent with the results, the only possible
conception that can be accepted of the Aether, is that it is
gravitative, and consequently possesses mass and inertia, and therefore
has a capacity not only to accept motion, but also to transmit motion to
another body, and impart the motion which it has accepted to a colder
body.

By imparting such motion, it increases the motion of the cold body, and
gradually changes its state fro