he writes as follows: "We cannot help
thinking that in every place where we find these lines of force, some
physical state or action must exist in sufficient energy to produce the
actual phenomena." Maxwell then went on to show what these physical
actions were, which took place in the dielectric--that is, the medium
surrounding the electrified body which we now know to be the Aether.

This electric field, he pointed out, was "in a state of stress, which
consisted of pressures or tensions different in different directions at
the same part of the medium. The relation of these forces were
threefold, and consisted in the most general type of stress of three
pressures or tensions in directions at right angles to each other."

Thus, in Maxwell's opinion, the existence of a medium, which by its
physical character was able to exert energy on material bodies, was one
of the fundamental hypotheses of his theory as to the physical character
of Faraday's Lines of Force.

This physical medium was to be capable of certain motions, and both
electric and magnetic forces were produced by its motions and its
stresses. Maxwell's conception, however, of the physical lines of force
was more or less hypothetical, and up to the present, as far as I can
learn, has not received that authority from science that such a
hypothesis requires to make it an accepted theory in science.

But what I venture to point out is, that with the view of the aetherial
medium that is submitted in this work, Maxwell's hypothesis remains a
hypothesis no longer, and that the hypothetical character of his theory
ceases to exist. For, by our conception of an atomic and gravitative
Aether, we are able to see that his physical lines of force are indeed
physical, and that his brilliant hypothesis now receives a true physical
foundation which otherwise it would not receive from a frictionless
Aether.

There is nothing, I venture to predict, in Maxwell's hypothesis which
cannot be accounted for on a truly physical basis, by the conception of
the Aether as given in this work. So that when Faraday saw in his mind's
eye lines of force traversing space, he saw by his imagination that
which was actually the real state of affairs, and when Maxwell enlarged
the conception by giving to those lines of force a definite atomic and
cellular structure, he, too, but anticipated the real nature and
character of the Aether as given in Chapter IV., which theory is the
direct outcome of