4, tom. i. pp.
638, 642.

489. M.A. de la Rive investigated this subject particularly, and published
a paper on it in 1825[A]. He thinks those who have referred the phenomena
to the attractive powers of the poles, rather express the general fact than
give any explication of it. He considers the results as due to an actual
combination of the elements, or rather of half of them, with the
electricities passing from the poles in consequence of a kind of play of
affinities between the matter and electricity[B]. The current from the
positive pole combining with the hydrogen, or the bases it finds there,
leaves the oxygen and acids at liberty, but carries the substances it is
united with across to the negative pole, where, because of the peculiar
character of the metal as a conductor[C], it is separated from them,
entering the metal and leaving the hydrogen or bases upon its surface. In
the same manner the electricity from the negative pole sets the hydrogen
and bases which it finds there, free, but combines with the oxygen and
acids, carries them across to the positive pole, and there deposits
them[D]. In this respect M. de la Rive's hypothesis accords in part with
that of MM. Riffault and Chompre (485.).

[A] Annales de Chimie, tom, xxviii. p. 190.

[B] Ibid. pp. 200, 202.

[C] Ibid. p. 202.

[D] Ibid. p. 201.

490. M. de la Rive considers the portions of matter which are decomposed to
be those contiguous to _both_ poles[A]. He does not admit with others the
successive decompositions and recompositions in the whole course of the
electricity through the humid conductor[B], but thinks the middle parts are
in themselves unaltered, or at least serve only to conduct the two contrary
currents of electricity and matter which set off from the opposite
poles[C]. The decomposition, therefore, of a particle of water, or a
particle of salt, may take place at either pole, and when once effected, it
is final for the time, no recombination taking place, except the momentary
union of the transferred particle with the electricity be so considered.

[A] Annales de Chimie, tom, xxviii. pp. 197, 198.

[B] Ibid. pp. 192, 199.

[C] Ibid. p. 200.

491. The latest communication that I am aware of on the subject is by M.
Hachette: its date is October 1832[A]. It is incidental to the description
of the decomposition of water by the magneto-electric currents (346.). One
of the results of the experiment is, that "it is not n