capable of assuming the condition of solid matter to a degree
surpassing ordinary solidity. As an exceptional kind of metal it forms
the counter-pole to mercury, in which the solid-fluid condition
characteristic of all metallic matter is as much shifted towards the
fluid as in iron it is to the solid. (Note in this respect the peculiar
resistance of iron to the liquefying effect which mercury has on the
other metals.)

This picture of magnetism enables us to understand at once why it must
occur together with heat at the place where an electric polarity has
been cancelled by the presence of a conductor. We have seen that
electricity is levity coupled in a peculiar way with gravity; it is
polarized levity (accompanied by a corresponding polarization of
gravity). An electric field, therefore, always has both qualities,
those of levity and of gravity. We saw a symptom of this in electrical
attraction and repulsion, so called; the attraction, we found, was due
to negative density, the repulsion to positive density, imparted to
space by the electrical fields present there. Now we see that when,
through the presence of a conductor, the electrical field round the two
opposing poles vanishes, in its place two other fields, a thermal and a
magnetic, appear. Clearly, one of them represents the levity-part, the
other the gravity-part, of the vanished electric field. The whole
process reminds one of combustion through which the ponderable and
imponderable parts, combined in the combustible substance, fall apart
and appear on the one hand as heat, and on the other as oxidized
substance ('ash'). Yet, between these two manifestations of heat there
is an essential qualitative difference.

Although, from our view-point, magnetism represents only one 'half of a
phenomenon, the other half of which is heat, we must not forget that it