perpendicular to an electric current; and we should expect that, if the
molecules of an iron wire possessed inherent polarity and could rotate,
a similar effect would take place in the interior of the wire to that
observed by Oersted. Wiedermann first remarked this effect, and it has
been known as circular magnetism. This circle, however, consists really
in each molecule having placed itself perpendicular to the current,
simply obeying Oersted's law, and thus forming a complete circle in
which the mutual attractions of the molecules forming that circle are
satisfied, as shown as C, Fig. 1. This wire becomes completely neutral,
any previous symmetrical arrangement of polarity rotating to form its
complete circle of attractions; and we can thus form in hard iron and
steel a neutrality extremely difficult to break up or destroy. We have
evident proof that this neutrality consists of a closed chain, or
circle, as by torsion we can partially deflect them on either side; thus
from a perfect externally neutral wire, producing either polarity, by
simple mechanical angular displacement of the molecules, as by right or
left handed torsion.

If we magnetize a wire placed east and west, it will retain this
polarity until freed by vibrations, as already remarked. If we pass an
electric current through this magnetized wire, we can notice the gradual
rotation of the molecules, and the formation of the circular neutrality.
If we commence with a weak current, gradually increasing its strength,
we can rotate them as slowly as may be desired. There is no sudden break
or haphazard moment of neutrality: the movements to perfect zero are
accomplished with perfect symmetry throughout.

We can produce a more perfect and shorter circle of attractions by the
superposition of magnetism, as at B, Fig. 1. If we magnetize a piece
of steel or iron in a given direction with a strong magnetic directing