dies as glass, lac, sulphur, &c., the particles
appear to be able to become polarized in all directions, for a mass when
experimented upon so as to ascertain its inductive capacity in three or
more directions (1690.), gives no indication of a difference. Now as the
particles are fixed in the mass, and as the direction of the induction
through them must change with its change relative to the mass, the constant
effect indicates that they can be polarized electrically in any direction.
This accords with the view already taken of each particle as a whole being
a conductor (1669.), and, as an experimental fact, helps to confirm that
view.
1689. But though particles may thus be polarized in _any_ direction under
the influence of powers which are probably of extreme energy (1686.), it
does not follow that each particle may not tend to polarize to a greater
degree, or with more facility, in one direction than another; or that
different kinds may not have specific differences in this respect, as they
have differences of conducting and other powers (1296. 1326. 1395.). I
sought with great anxiety for a relation of this nature; and selecting
crystalline bodies as those in which all the particles are symmetrically
placed, and therefore best fitted to indicate any result which might depend
upon variation of the direction of the forces to the direction of the
particles in which they were developed, experimented very carefully with
them. I was the more strongly stimulated to this inquiry by the beautiful
electrical condition of the crystalline bodies tourmaline and boracite, and
hoped also to discover a relation between electric polarity and that of
crystallization, or even of cohesion itself (1316.). My experiments have
not established any connexion of the kind sought for. But as I think it of
equal importance to show either that there is or is not such a relation, I
shall briefly describe the results.
1690. The form of experiment was as follows. A brass ball 0.73 of an inch
in diameter, fixed at the end of a horizontal brass rod, and that at the
end of a brass cylinder, was by means of the latter connected with a large
Leyden battery (291.) by perfect metallic communications, the object being
to keep that ball, by its connexion with the charged battery in an
electrified state, very nearly uniform, for half an hour at a time. This
was the inductric ball. The inducteous ball was the carrier of the torsion
electrometer (1229. 1314.);
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