oes through the other, as in the former case,
it may quite lose its velocity, and come to a standstill in the air
till the other has moved on to a distance, when it will start up in
its former direction.

12. If two rings be formed side by side, they will instantly collide
at their edges, showing strong attraction.

13. If the collision does not destroy them, they may either break
apart at the point of the collision, and then weld together into a
single ring with twice the diameter, and then move on as if a single
ring had been formed, or they may simply bounce away from each
other, in which case they always rebound _in a plane_ at right
angles to the plane of collision. That is, if they collided on their
sides, they would rebound so that one went up and the other down.

14. Three may in like manner collide and fuse into a single ring.

Such rings formed in air by a locomotive may rise wriggling in the air
to the height of several hundred feet, but they are soon dissolved and
disappear. This is because the friction and viscosity of the air robs
the rings of their substance and energy. If the air were without
friction this could not happen, and the rings would then be persistent,
and would retain all their qualities.

Suppose then that such rings were produced in a medium without friction
as the ether is believed to be, they would be permanent structures with
a variety of properties. They would occupy space, have definite form and
dimensions, momentum, energy, attraction and repulsion, elasticity; obey
the laws of motion, and so far behave quite like such matter as we know.
For such reasons it is thought by some persons to be not improbable
that the atoms of matter are minute vortex-rings of ether in the ether.
That which distinguishes the atom from the ether is the form of motion
which is embodied in it, and if the motion were simply arrested, there
would be nothing to distinguish the atom from the ether into which it
dissolved. In other words, such a conception makes the atoms of matter a
form of motion of the ether, and not a created something put into the
ether.

THE ETHER IS STRUCTURELESS.

If the ether be the boundless substance described, it is clear it can
have no form as a whole, and if it be continuous it can have no minute
structure. If not constituted of atoms or molecules there is nothing
descriptive that can be said about it. A molecule or a particular mass
of matter could be identified by its for