this subject. Some have
given all their attention to what goes on in matter, and have called
that electricity; others have given their attention to what goes on in
the ether, and have called that electricity, and some have considered
both as being the same thing, and have been confounded.

Let us consider what is the relation between an electrified body and the
ether about it.

When a body is electrified, the latter at the same time creates an ether
stress about it, which is called an electric field. The ether stress may
be considered as a warp in the distribution of the energy about the body
(Fig. 15), by the new positions given to the molecules by the process of
electrification. It has been already said that the evidence from other
sources is that atoms, rather than molecules, in larger masses, are what
affect the ether. One is inclined to inquire for the evidence we have as
to the constitution of matter or of atoms. There is only one hypothesis
to-day that has any degree of probability; that is, the vortex-ring
theory, which describes an atom as being a vortex-ring of ether in the
ether. It possesses a definite amount of energy in virtue of the motion
which constitutes it, and this motion differentiates it from the
surrounding ether, giving it dimensions, elasticity, momentum, and the
possibility of translatory, rotary, vibratory motions, and combinations
of them. Without going further into this, it is sufficient, for a
mechanical conception, that one should have so much in mind, as it will
vastly help in forming a mechanical conception of reactions between
atoms and the ether. An exchange of energy between such an atom and the
ether is not an exchange between different kinds of things, but between
different conditions of the same thing. Next, it should be remembered
that all the elements are magnetic in some degree. This means that they
are themselves magnets, and every magnet has a magnetic field unlimited
in extent, which can almost be regarded as a part of itself. If a magnet
of any size be moved, its field is moved with it, and if in any way the
magnetism be increased or diminished, the field changes correspondingly.

[Illustration: FIG. 15.]

Assume a straight bar electro-magnet in circuit, so that a current can
be made intermittent, say, once a second. When the circuit is closed and
the magnet is made, the field at once is formed and travels outwards at
the rate of 186,000 miles per second. When the current