a universal law,
and such a result is opposed to all experience and experiment. Again,
let us apply our third Rule of Philosophy to this supposed
gravitationless Aether, and see what the result is.

Our third rule states, that any hypothesis put forward must satisfactorily
account for the phenomena sought to be explained and accounted for. The
Aether was conceived in order to explain the phenomena of light, and one
of the properties it was conceived to possess was elasticity, yet that
very conception was devoid of the most fundamental property of matter,
without which there is no elasticity, that is, that it was not atomic.

I have already shown in Art. 44, that Aether is atomic, and therefore
there is given to the Aether a structure which is capable of exhibiting
elasticity, inertia, density, and even Gravitation, while at the same
time, the conception is fully in harmony with philosophical reasoning
and Newton's Rules of Philosophy.

Let us consider the question whether Aether is, or is not gravitative,
from another aspect. For several hundred years, the physical cause of
Gravitation has been outstanding, while the world has held the
conception that Aether is a gravitationless and frictionless medium. The
earth has been rolling on in her orbit year in, year out, together with
all the other planets in their annual march round the sun, and yet
through all that time no one has been able to suggest, or give any
satisfactory or adequate physical explanation, as to what moves the
earth along.

I am fully aware that Newton suggested and proved, that it was because
of the Law of Gravitation. But I look upon that as a mathematical
explanation and not as a physical one.

Now I venture to predict this, that on the assumption of a
gravitationless medium, the physical explanation so longed for will
always be outstanding, as a gravitationless Aether is synonymous with a
frictionless medium, and so long as we admit that there is a
frictionless medium, so long will the physical cause of Gravitation, and
therefore the physical cause of all the movements of the planets and
comets, be outstanding and unexplained.

If, however, instead of being illogical in our reasoning, we become
logical, and affirm that Aether is matter, and because all matter is
gravitative, therefore Aether is gravitative; and if, instead of being
unphilosophical, we become philosophical, and affirm that because a
gravitationless Aether violates both the firs