ntial part of the
arrangement, namely, where oxygen goes to the electrolyte[A]. The first may
be considered as a case where the current is put into motion by the
abstraction of oxygen from hydrogen, the latter by that of hydrogen from
oxygen. The direction of the electric current is in both cases the same,
when referred to the direction in which the elementary particles of the
electrolyte are moving (923. 962.), and both are equally in accordance with
the hypothetical view of the inductive action of the particles just
described (1740.).

[A] Philosophical Magazine, 1838, xii. 225, 315. also De la Rive's
results with peroxide of manganese. Annales de Chimie, 1836, lxi. p.
40.--_Dec. 1838._

1743. In such a view of voltaic excitement, the action of the particles may
be divided into two parts, that which occurs whilst the force in a particle
of oxygen is rising towards a particle of zinc acting on it, and falling
towards the particle of hydrogen with which it is associated (this being
the progressive period of the inductive action), and that which occurs when
the change of association takes place, and the particle of oxygen leaves
the hydrogen and combines with the zinc. The former appears to be that
which produces the current, or if there be no current, produces the state
of tension at the termination of the battery; whilst the latter, by
terminating for the time the influence of the particles which have been
active, allows of others coming into play, and so the effect of current is
continued.

1744. It seems highly probable, that excitement by friction may very
frequently be of the same character. Wollaston endeavoured to refer such
excitement to chemical action[A]; but if by chemical action ultimate union
of the acting particles is intended, then there are plenty of cases which
are opposed to such a view. Davy mentions some such, and for my own part I
feel no difficulty in admitting other means of electrical excitement than
chemical action, especially if by chemical action is meant a final
combination of the particles.

[A] Philosophical Transactions, 1801, p. 427.

1745. Davy refers experimentally to the opposite states which two particles
having opposite chemical relations can assume when they are brought into
the close vicinity of each other, but _not_ allowed to combine[A]. This, I
think, is the first part of the action already described (1743.); but in my
opinion it cannot give rise to a continuous cur