errella.[201]

* * * * *

CHAP. II.

The Directive or Versorial Virtue (which we call
verticity): what it is, how it exists in the loadstone;
_and in what way it is acquired when innate._

Directive force, which is also called by us verticity, is a virtue which
spreads by an innate vigour from the aequator in both directions toward the
poles. That power, inclining in both directions towards the termini, causes
the motion of direction, and produces a constant and permanent position in
Nature, not only in the earth itself but also in all magneticks. Loadstone
is found either in veins of its own or in iron mines, when the homogeneous
substance of the earth, either having or assuming a primary form, is
changed or concreted into a stony substance, which besides the primary
qualities of its nature has various dissimilitudes and differences in
different quarries and mines, as if from different matrices, and very many
secondary qualities and varieties in its substance. A loadstone which is
dug out in this breaking up of the earth's surface and of protuberances
upon it, whether formed complete in itself (as sometimes in China) or in a
larger vein, is fashioned by the earth and follows the nature of the whole.
All the interior parts of the earth mutually conspire together in
combination and produce direction toward north and south. But those
magnetical bodies which come together in the uppermost parts of the earth
are not true united parts of the whole, but appendages and parts joined on,
imitating the nature of the whole; wherefore when floating free on water,
they dispose themselves just in the same way as they are placed in the
terrestrial system of nature. We had a large loadstone of twenty pounds *
weight, dug up and cut out of its vein, after we had first observed and
marked its ends; then after it was dug out, we placed it in a boat on
water, so that it could turn freely; then immediately the face which had
looked toward the north in the quarry began to {120} turn to the north on
the waves and at length settled toward that point. For that face which
looked toward the north in the quarry is the southern, and is attracted by
the northern parts of the earth, [Illustration] in the same way as pieces
of iron which acquire their verticity from the earth. About this point we
intend to speak afterwards[202] under change of verticity. But there is a
different rotation of the internal parts of the