power, the magnetism penetrates to a certain depth. If we slightly
diminish the magnetizing power, and magnetize the rod in a contrary
direction, we may reduce it to zero, by the superposition of an exterior
magnetism upon one of a contrary name existing at a greater depth; and
if we continue this operation, gradually diminishing the force at each
reversal, we can easily superpose ten or more distinct symmetrical
arrangements, and, as their mutual attractions are satisfied in a
shorter circle than in that produced by electricity, it is extremely
difficult to destroy this formation when once produced.

The induction balance affords also some reasons for believing that the
molecules not only form a closed circle of attractions, as at B, but
that they can mutually react upon each other, so as to close a circle
of attractions as a double molecule, as shown at A. The experimental
evidence, however, is not sufficient to dwell on this point, as the
neutrality obtained by superposition is somewhat similar in its external
effects.

We can produce a perfectly symmetrical closed circle of attractions of
the nature of the neutrality of C, Fig. 3, by forming a steel wire into
a closed circle, 10 centimeters in diameter, if this wire is well joined
at its extremities by twisting and soldering. We can then magnetize this
ring by slowly revolving it at the extremity of one pole of a strong
permanent magnet; and, to avoid consequent poles at the part last
touching the magnet, we should have a graduating wedge of wood, so that
while revolving it may be gradually removed to greater distance. This
wire will then contain no consequent points or external magnetism: it
will be found perfectly neutral in all parts of its closed circle. Its
neutrality is similar to C, Fig. 3; for if we cut this wire at any point
we find extremely strong magnetic polarity, being magnetized by this