d great precision of expression on the other
(505.).

511. In speaking of the current, I find myself obliged to be still more
particular than on a former occasion (283.), in consequence of the variety
of views taken by philosophers, all agreeing in the effect of the current
itself. Some philosophers, with Franklin, assume but one electric fluid;
and such must agree together in the general uniformity and character of the
electric current. Others assume two electric fluids; and here singular
differences have arisen.

512. MM. Riffault and Chompre, for instance, consider the positive and
negative currents each as causing decomposition, and state that the
positive current is _more powerful_ than the negative current[A], the
nitrate of soda being, under similar circumstances, decomposed by the
former, but not by the latter.

[A] Annales de Chimie, 1807, tom, lxiii. p. 84.

513. M. Hachette states[A] that "it is not necessary, as has been believed,
that the action of the two electricities, positive and negative, should be
simultaneous for the decomposition of water." The passage implying, if I
have caught the meaning aright, that one electricity can be obtained, and
can be applied in effecting decompositions, independent of the other.

[A] Annales de Chimie, 1832, tom. li. p. 73.

514. The view of M. de la Rive to a certain extent agrees with that of M.
Hachette, for he considers that the two electricities decompose separate
portions of water (490.)[A]. In one passage he speaks of the two
electricities as two influences, wishing perhaps to avoid offering a
decided opinion upon the independent existence of electric fluids; but as
these influences are considered as combining with the elements set free as
by a species of chemical affinity, and for the time entirely masking their
character, great vagueness of idea is thus introduced, inasmuch as such a
species of combination can only be conceived to take place between things
having independent existences. The two elementary electric currents, moving
in opposite directions, from pole to pole, constitute the ordinary _voltaic
current._

[A] Annales de Chimie, 1825, tom, xxviii. pp. 197, 201.

515. M. Grotthuss is inclined to believe that the elements of water, when
about to separate at the poles, combine with the electricities, and so
become gases. M. de la Rive's view is the exact reverse of this: whilst
passing through the fluid, they are, according to him, compound