of a body (Art. 85), and further, that its intensity is inversely as the
square of the distance (Arts. 66, 74 and 84).

We have, however, discovered that the physical cause of the centrifugal
force is due to the pressure of the electro-magnetic Aether (Art. 96).
If, therefore, the physical cause of that law which is the complement
and counterpart of Gravitation Attraction is to be found, and alone
found, in the pressure and motions of the electro-magnetic Aether, then
it is only logical and reasonable to infer that the physical cause of
the Attraction of Gravitation is to be found in the same
electro-magnetic Aether. That the Attraction of Gravitation is to be
found in this medium is now an accepted hypothesis among scientists.
Because, unless the physical cause of Gravitation Attraction is to be
found in this electro-magnetic Aether, then, in order to account for
that attraction, we should have to postulate the existence of another
medium in space, in lieu of the Aether, which would be to the
centripetal force what the Aether is to the centrifugal force. This
would be distinctly unphilosophical, as it would be a violation of the
first two rules of our philosophy, in that it would not be simple in its
conception, and that such a hypothesis would imply the existence of two
media which would occupy the same planetary and interstellar space at
one and the same time, and this is a violation of all experience in its
widest form.

Therefore the physical cause of Gravitation must be sought for in the
same medium which gives the physical cause of the companion force, and
that medium is the electro-magnetic Aether. Professor Preston in his
_Theory of Light_ is of this opinion. In Art. 327 he writes: "To account
for the propagation of heat and light, that is, of radiant energy, we
have postulated the existence of a medium filling all space. But the
transference of the energy of radiant heat and light is not the only
evidence we have in favour of the existence of an Aether. Electric,
magnetic and electro-magnetic phenomena and Gravitation itself point in
the same direction."

Professor Lodge, in his _Modern Views of Electricity_, is even more
explicit in his statement of the case. On page 338 he states:
"Gravitation is explainable by differences of pressure in the medium
(_i. e._ the Aether) caused by some action between it and matter not
yet understood." Further, Newton himself suggested that the physical
cause of Gravitation