method to saturation, and having retained (which it will indefinitely)
its circle of attractions complete.

I have already shown that soft iron, when its molecules are allowed
perfect freedom by vibration, invariably takes the polarity of the
external directing influence, such as that of the earth, and it does so
even with greater freedom under the influence of heat. Manufacturers of
electro-magnets for telegraphic instruments are very careful to choose
the softest iron and thoroughly anneal it; but very few recognize the
importance as regards the position of the iron while annealing it under
the earth's directing influence. The fact, however, has long since been
observed.

Dr. Hooke, 1684, remarked that steel or iron was magnetized when heated
to redness and placed in the magnetic meridian. I have slightly varied
this experiment by heating to redness three similar steel bars, two
of which had been previously magnetized to saturation, and placed
separately with contrary polarity as regards each other, the third being
neutral. Upon cooling, these three bars were found to have identical and
similar polarity. Thus the molecules of this most rigid material, cast
steel, had become free at red heat, and rotated under the earth's
magnetic influence, giving exactly the same force on each; consequently
the previous magnetization of two of these bars had neither augmented
nor weakened the inherent polarity of their molecules. Soft iron gave
under these conditions by far the greatest force, its inherent polarity
being greater than that of steel.

I have made numerous other experiments bearing upon the question of
neutrality, but they all confirm those I have cited, which I consider
afford ample evidence of the symmetrical arrangement of neutrality.