consideration is that the magnetic
field itself, when moved in space, suffers no frictional resistance.
There is no magnetic energy wasted through ether inertia. These
phenomena show that whether the ether exhibits the quality called
inertia depends upon the kind of motion it has.

18. MATTER IS MAGNETIC.

The ordinary phenomenon of magnetism is shown by bringing a piece of
iron into the neighbourhood of a so-called magnet, where it is attracted
by the latter, and if free to move will go to and cling to the magnet. A
delicately suspended magnetic needle will be affected appreciably by a
strong magnet at the distance of several hundred feet. As the strength
of such action varies inversely as the square of the distance from the
magnet, it is evident there can be no absolute boundary to it. At a
distance from an ordinary magnet it becomes too weak to be detected by
our methods, not that there is a limit to it. It is customary to think
of iron as being peculiarly endowed with magnetic quality, but all kinds
of matter possess it in some degree. Wood, stone, paper, oats, sulphur,
and all the rest, are attracted by a magnet, and will stick to it if the
magnet be a strong one. Whether a piece of iron itself exhibits the
property depends upon its temperature, for near 700 degrees it becomes
as magnetically indifferent as a piece of copper at ordinary
temperature. Oxygen, too, at 200 degrees below the zero of Centigrade
adheres to a magnet like iron.

In this as in so many other particulars, how a piece of matter behaves
depends upon its temperature, not that the essential qualities are
modified in any degree, but temperature interferes with atomic
arrangement and aggregation, and so disguises their phenomena.

As every kind of matter is thus affected by a magnet, the manifestations
differing but in degree, it follows that all kinds of atoms--all the
elements--are magnetic. An inherent property in them, as much so as
gravitation or inertia; apparently a quality depending upon the
structure of the atoms themselves, in the same sense as gravitation is
thus dependent, as it is not a quality of the ether.

An atom must, then, be thought of as having polarity, different
qualities on the two sides, and possessing a magnetic field as extensive
as space itself. The magnetic field is the stress or pressure in the
ether produced by the magnetic body. This ether pressure produced by a
magnet may be as great as a ton per square inch.