of its
length; because, forsooth, in the case of a long stone, a magnetick is
directed at the end straight towards the body in which the virtue proceeds
in straighter lines and through the longer diameter. But a somewhat long
stone has but little power on the side, much less indeed than a round one.
It is demonstrable[180], indeed, that at A and B the coition is * stronger
in a round stone than at C and D, at like distances from the pole.

[Illustration]

* * * * *

CHAP. XXXII.

Certain Problems and Magnetick Experiments about
the Coition, and Separation, and regular Motion
_of bodies magnetical_.

Equal loadstones come together with equal incitation. *

Also magnetick bodies of iron, if alike in all respects, * come together
when excited with similar incitation.

Furthermore, bodies of iron not excited by a * loadstone, if they are alike
and not weighed down by their bulk, move towards one another with equal
motion.

Two loadstones, disposed on the surface of some water in {100} suitable
skiffs, if they are drawn up suitably within their orbes of virtue, incite
one another mutually to an embrace. So a proportionate * piece of iron in
one skiff hurries with the same speed towards the loadstone as the
loadstone itself in its boat strives towards the iron. From their own
positions, indeed, they are so borne together, that they are joined and
come to rest at length in the middle of the space. Two iron wires
magnetically excited, floating in water by means of * suitable pieces of
cork, strive to touch and mutually strike one another with their
corresponding ends, and are conjoined.

Coition is firmer and swifter than repulsion and separation in * equal
magnetick substances. That magnetick substances are more sluggishly
repelled than they are attracted is manifest in all magnetical experiments
in the case of stones floating on water in suitable skiffs; also in the
case of iron wires or rods swimming (transfixed through corks) and well
excited by a loadstone, and in the case of versoria. This comes about
because, though there is one faculty of coition, another of conformation or
disposition, repulsion and aversion is caused merely by something
disposing; on the other hand, the coming together is by a mutual alluring
to contact and a disposing, that is, by a double vigour.

A disponent vigour is often only the precursor of coition, in order that
the bodies may stand conveniently