Electro-Chemical Decomposition      59
• 223. M. Biot does not appear to admit the successive de-
compositions and recompositions spoken of by Grotthuss, Davy,
etc., etc.; but seems to consider the substance whilst in transit
as combined with, or rather attached to, the electricity for the
time,1 and though it communicates this electricity to the sur-
rounding undecomposed matter with which it is in contact, yet
it retains during the transit a little superiority with respect to
that kind which it first received from the pole, and is, by virtue
of that difference, carried forward through the fluid to the
opposite pole.2
 224.	This theory implies that decomposition takes place at
both poles upon distinct portions of fluid, and not at all in the
intervening parts.   The latter serve merely as imperfect con-
ductors, which, assuming an electric state, urge particles elec-
trified more highly at the poles through them  in opposite
directions, by virtue of a series of ordinary electrical attractions
and repulsions.3
 225.	M. A. de la Rive investigated this subject particularly,
and published a paper on it in 1825.4   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.5   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,6 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.7   In this respect M. de la Rive's
hypothesis accords in part with that of MM. Riffault and
Chompre (221).
 226.	M. de la Rive considers the portions of matter which
are decomposed to be those contiguous to both poles.8   He
1	Precis Elementaire de Physique, sme Edition, 1824, torn. i. p. 636.
2	Ibid. p. 642.	3 Ibid. pp. 638, 642.
4 Annales de Chimie, torn, xxviii. p. 190.	5 Ibid. pp. 200, 202.
6 Ibid. p. 202.	7 Ibid. p. 201.	8 Ibid. pp. 197, 198.