draws for all her supply of energy. Shall we ever discover how we
can replenish the dwindling resources of energy, or find out how we can
call into being the at present unavailable energy which is stored up in
uniform temperature?

It looks as if our successors would witness an interesting race,
between the progress of science on the one hand and the depletion of
natural resources upon the other. The natural rate of flow of energy
from its primary atomic reservoirs to the sea of waste heat energy
of uniform temperature, allows life to proceed at a complete pace
sternly regulated by the inexorable laws of supply and demand,
which the biologists have recognised in their field as the struggle
for existence.[5]

[5] _Matter and Energy_, by Professor Soddy.

It is certain that energy is an actual entity just as much as matter,
and that it cannot be created or destroyed. Matter and ether are
receptacles or vehicles of energy. As we have said, what these entities
really are in themselves we do not know. It may be that all forms of
energy are in some fundamental way aspects of the same primary entity
which constitutes matter: how all matter is constituted of particles of
electricity we have already seen. The question to which we await an
answer is: What is electricity?

Sec. 15

MATTER, ETHER, AND EINSTEIN

The supreme synthesis, the crown of all this progressive conquest of
nature, would be to discover that the particles of positive and negative
electricity, which make up the atoms of matter, are points or centres of
disturbances of some kind in a universal ether, and that all our
"energies" (light, magnetism, gravitation, etc.) are waves or strains of
some kind set up in the ether by these clusters of electrons.

It is a fascinating, tantalising dream. Larmor suggested in 1900 that
the electron is a tiny whirlpool, or "vortex," in ether; and, as such a
vortex may turn in either of two opposite ways, we seem to see a
possibility of explaining positive and negative electricity. But the
difficulties have proved very serious, and the nature of the electron is
unknown. A recent view is that it is "a ring of negative electricity
rotating about its axis at a high speed," though that does not carry us
very far. The unit of positive electricity is even less known. We must
be content to know the general lines on which thought is moving toward
the final unification.

We say "unification,"