fore, under the influence of the
repulsive and attractive forces, from the charged conductor towards the
nearest uninsulated conductor, or the nearest body in a different state to
themselves, just as charged particles of dust would travel, and are then
discharged; each particle acting, in its course, as a centre of inductive
force upon any bodies near which it may come. The travelling of these
charged particles when they are numerous, causes wind and currents, but
these will come into consideration under _carrying discharge_ (1319. 1562.
&c.).

1443. When air is said to be electrified, and it frequently assumes this
state near electrical machines, it consists, according to my view, of a
mixture of electrified and unelectrified particles, the latter being in
very large proportion to the former. When we gather electricity from air,
by a flame or by wires, it is either by the actual discharge of these
particles, or by effects dependent on their inductive action, a case of
either kind being produceable at pleasure. That the law of equality between
the two forces or forms of force in inductive action is as strictly
preserved in these as in other cases, is fully shown by the fact, formerly
stated (1173. 1174.), that, however strongly air in a vessel might be
charged positively, there was an exactly equal amount of negative force on
the inner surface of the vessel itself, for no residual portion of either
the one or the other electricity could be obtained.

1444. I have nowhere said, nor does it follow, that the air is charged only
where the luminous brush appears. The charging may extend beyond those
parts which are visible, i.e. particles to the right or left of the lines
of light may receive electricity, the parts which are luminous being so
only because much electricity is passing by them to other parts (1437.);
just as in a spark discharge the light is greater as more electricity
passes, though it has no necessary relation to the quantity required to
commence discharge (1370. 1420.). Hence the form we see in a brush may by
no means represent the whole quantity of air electrified; for an invisible
portion, clothing the visible form to a certain depth, may, at the same
time, receive its charge (1552.).

1445. Several effects which I have met with in muriatic acid gas tend to
make me believe, that that gaseous body allows of a dark discharge. At the
same time, it is quite clear from theory, that in some gases, the reverse