the cork, and you will see that it has
lost the verticity * which it had acquired from the stone. From these
experiments it is clear how difficult it is for the property of polarity
implanted by the loadstone to be destroyed. But if a small loadstone had
remained as long in the same fire, it would have lost its strength. Iron,
because it does not so easily perish, and is not so easily burnt up as very
many loadstones, retains its strength more stably, and when it is lost can
recover it again from a loadstone; but a loadstone when burnt does not
revive. But now that iron, which has * been deprived of its magnetick form,
moves in a different way from any other piece of iron, for it has lost its
polar nature; and whereas before the touch of the loadstone it may have had
a motion toward the north, and after contact toward the south; now it turns
to no definite and particular point; but afterwards, very slowly and after
* a long time, it begins to turn in a doubtful fashion toward the poles of
the earth (having acquired some power from the earth). I have said that the
cause of direction was twofold, one implanted in the stone and iron, but
the other in the earth, implanted by the disponent virtue; and for that
reason (the distinction of poles and the verticity in the iron having now
been destroyed) a slow and weak directive power is acquired anew from the
verticity of the earth. We may see, therefore, with what difficulty and
only by the application of hot fires and by long ignition of the iron
heated to softness, the imparted magnetick virtue is eradicated. When this
ignition has overcome the acquired polarity, and it has been now completely
subdued and not awakened again, that iron is left unsettled and utterly
incapable of direction. But we must further inquire how iron remains
affected by verticity. It is manifest that it strongly affects and changes
the nature of the iron, because the presence of a loadstone attracts the
iron to itself with an altogether wonderful readiness. Nor is it only the
part that is rubbed, but on account of the rubbing (on one end only) the
whole iron is affected together, and gains by it a permanent though an
unequal power. This is demonstrated as follows. Rub an iron wire on the end
so * that it is excited, and it will turn towards the north; afterward cut
off some portion of it; you will see that it still turns toward the north
(as before), but more feebly. For it must be understood that the loa