on--Ether stress and atomic
position--Nature of an electric current--Electricity
a condition, not an entity.

So far as we have knowledge to-day, the only factors we have to consider
in explaining physical phenomena are: (1) Ordinary matter, such as
constitutes the substance of the earth, and the heavenly bodies; (2) the
ether, which is omnipresent; and (3) the various forms of motion, which
are mutually transformable in matter, and some of which, but not all,
are transformable into ether forms. For instance, the translatory motion
of a mass of matter can be imparted to another mass by simple impact,
but translatory motion cannot be imparted to the ether, and, for that
reason, a body moving in it is not subject to friction, and continues
to move on with velocity undiminished for an indefinite time; but the
vibratory motion which constitutes heat is transformable into
wave-motion in the ether, and is transmitted away with the speed of
light. The kind of motion which is thus transformed is not even a
to-and-fro swing of an atom, or molecule, like the swing of a pendulum
bob, but that due to a change of form of the atoms within the molecule,
otherwise there could be no such thing as spectrum analysis. Vibratory
motion of the matter becomes undulatory motion in the ether. The
vibratory motion we call heat; the wave-motion we call sometimes radiant
energy, sometimes light. Neither of these terms is a good one, but we
now have no others.

It is conceded that it is not proper to speak of the wave-motion in the
ether as _heat_; it is also admitted that the ether is not heated by the
presence of the wave--or, in other words, the temperature of the ether
is absolute zero. Matter only can be heated. But the ether waves can
heat other matter they may fall on; so there are three steps in the
process and two transformations--(1) vibrating matter; (2) waves in the
ether; (3) vibration in other matter. Energy has been transferred
indirectly. What is important to bear in mind is, that when a form of
energy in matter is transformed in any manner so as to lose its
characteristics, it is not proper to call it by the same name after as
before, and this we do in all cases when the transformation is from one
kind in matter to another kind in matter. Thus, when a bullet is shot
against a target, before it strikes it has what we call mechanical
energy, and we measure that in foot-pounds; after it has struck the
target, the transform