very strong opposing effect or counter potential. The evolution
of magnetic lines, or the opening out of magnetic circuits, goes on at
a very rapid rate. Each line or magnetic circuit evolved, and cutting
the conductor, flies at once outward, and locates itself in the iron
ring. This ring can carry innumerable lines, and they do not crowd one
another. It permits the lines even to lengthen in reaching it, and
yet, on account of its low resistance to their passage, the
lengthening is equivalent to their having shortened in other media. We
will suppose the current not sufficient to exhaust this peculiar
capacity for lines which the iron has. Equilibrium is reached, the
conductor has opened up innumerable closed circuits, and caused them
to exist in the ring still closed; but in iron, not space or ether
merely. The current passing has continued its action and storage of
energy until to emit another line in view of the resistance now found
in the crowded iron ring is impossible.

Now let us cut off the current. We are surprised to find a very weak
extra current, a practical absence of self-induction on breaking, or,
at least, a giving out of energy in nowise comparable to that on
making. Let us put on the current as it was before. Another curious
result. But little self-induction now on making energy not absorbed.

Now cut off the current again. Same effect as before. Now let us put
on the current reversed in direction. At once we find a very strong
counter potential or opposing self-induction developed.

The ring had been polarized, or retained its magnetic energy, and we
are now taking out one set of lines and putting in reversely polarized
lines of force. This done, we break the reversed current without much
effect of self-induction. The ring remains polarized and inert until
an opposite flow of current be sent through. Iron is then a different
medium from the ether.

The ring once magnetized must, in losing its magnetism, permit a
closure of the lines by shortening. This involves their passage from
the iron across the space in the center of the ring, notwithstanding
its great resistance to the lines of force. As passage from iron to
air is equivalent to lengthening of the lines, it is readily seen that
such lengthening may oppose more effect than a slight shortening due
to leaving iron, for air or space may give in provoking a closure and
disappearance of the lines. Looked at from another standpoint, the
lines on th