m by their vibrations, and that there are as many
ether waves per second as of molecular vibrations per second. In like
manner, the implication is the same, that if there be rotations in the
ether they must be produced by molecular rotation, and there must be as
many rotations per second in the ether as there are molecular rotations
that produce them. The space about a wire carrying a current is often
pictured as filled with whorls indicating this motion (Fig. 14), and one
must picture to himself, not the wire as a whole rotating, but each
individual molecule independently. But one is aware that the molecules
of a conductor are practically in contact with each other, and that if
one for any reason rotates, the next one to it would, from frictional
action, cause the one it touched to rotate in the opposite direction,
whereas, the evidence goes to show that all rotation is in the same
direction.

[Illustration: FIG. 14.]

How can this be explained mechanically? Recall the kind of action that
constitutes heat, that it is not translatory action in any degree, but
vibratory, in the sense of a change of form of an elastic body, and
this, too, of the atoms that make up the molecule of whatever sort. Each
atom is so far independent of every other atom in the molecule that it
can vibrate in this way, else it could not be heated. The greater the
amplitude of vibration, the more free space to move in, and continuous
contact of atoms is incompatible with the mechanics of heat. There must,
therefore, be impact and freedom alternating with each other in all
degrees in a heated body. If, in any way, the atoms themselves _were_
made to rotate, their heat impacts not only would restrain the
rotations, but the energy also of the rotation motion would increase the
vibrations; that is, the heat would be correspondingly increased, which
is what happens always when an electric current is in a conductor. It
appears that the cooler a body is the less electric resistance it has,
and the indications are that at absolute zero there is no resistance;
that is, impacts do not retard rotation, but it is also apparent that
any current sent through a conductor at that temperature would at once
heat it. This is the same as saying that an electric current could not
be sent through a conductor at absolute zero.

So far, mechanical conceptions are in accordance with electrical
phenomena, but there are several others yet to be noted. Electrical
phenomena