ches us. From experience we learn that the air is
gravitative, but we also learn that it is possible to be moved from
place to place as winds, and that as such it can move freely between the
trees of the forest, causing their boughs and leaves to tremble and bend
beneath its energy and power.

I have yet to learn, however, that while it moves between the trees as
separate and distinct objects, such a movement militates or destroys its
gravitating properties.

Does the air cease to be any less gravitative, or subject to the Law of
Gravity, when it is subject to certain movements, which give rise to
certain currents as winds? Such an assumption is altogether opposed to
philosophical reasoning.

Whether the air is stationary or in motion, it is ever subject to the
great Law of Gravitation, and accepting that as an analogy, the apparent
contradiction between the oft-quoted simile of Young and his fourth
hypothesis is at once removed, and from analogy we learn that it is
quite possible for Aether to move between bodies because of certain
currents which may be originated by heat, light or electricity, yet at
the same time the existence of such currents does not violate its
gravitating tendency.

Young's fourth hypothesis is therefore in perfect harmony with his
oft-quoted simile, that the Aether flows through the interstices of
bodies as the wind flows through a group of trees, but like the
air-currents it does not so flow unless the currents are generated by
some form of energy, as heat or light, electricity or magnetism.

From these considerations therefore we are compelled to come to the
conclusion that Aether, like all other matter, is subject to the same
universal Law of Gravitation. If further evidence of the gravitating
tendency of the Aether were required, I would refer the reader to Lord
Kelvin's utterance on this subject.

Lord Kelvin, _Phil. Mag._, November 1899, in relation to the Aether
writes: "We are accustomed to call Aether imponderable. How do we know
that it is imponderable? If we had never dealt with air except by our
senses, air would be imponderable to us, but we know by experiment that
a vacuum glass tube shows an increased weight when air is allowed to
flow into it. We have not the slightest reason to believe that Aether is
imponderable. It is just as likely to be attracted by the sun as air is.
At all events the _onus of proof rests with those who assert it is
imponderable_. I think we shall ha