ssa_, were sufficient to
form, with platina and zinc, powerful electromotive circles[B]; but he is
here speaking of the _production_ of electricity in the pile, and not of
its effects when evolved; nor do his words at all imply that any correction
of his former distinct statements relative to _decomposition_ was required.

[A] Journal of the Royal Institution, 1802, p. 53.

[B] Philosophical Transactions, 1826, p. 406.

474. I may refer to the last series of these Experimental Researches (380.
402.) as setting the matter at rest, by proving that there are hundreds of
bodies equally influential with water in this respect; that amongst binary
compounds, oxides, chlorides, iodides, and even sulphurets (402.) were
effective; and that amongst more complicated compounds, cyanides and salts,
of equal efficacy, occurred in great numbers (402.).

475. Water, therefore, is in this respect merely one of a very numerous
class of substances, instead of being the _only one_ and _essential_; and
it is of that class one of the _worst_ as to its capability of facilitating
conduction and suffering decomposition. The reasons why it obtained for a
time an exclusive character which it so little deserved are evident, and
consist, in the general necessity of a fluid condition (394.); in its being
the _only one_ of this class of bodies existing in the fluid state at
common temperatures; its abundant supply as the great natural solvent; and
its constant use in that character in philosophical investigations, because
of its having a smaller interfering, injurious, or complicating action upon
the bodies, either dissolved or evolved, than any other substance.

476. The analogy of the decomposing or experimental cell to the other cells
of the voltaic battery renders it nearly certain that any of those
substances which are decomposable when fluid, as described in my last paper
(402.), would, if they could be introduced between the metallic plates of
the pile, be equally effectual with water, if not more so. Sir Humphry Davy
found that litharge and chlorate of potassa were thus effectual[A]. I have
constructed various voltaic arrangements, and found the above conclusion to
hold good. When any of the following substances in a fused state were
interposed between copper and platina, voltaic action more or less powerful
was produced. Nitre; chlorate of potassa; carbonate of potassa; sulphate of
soda; chloride of lead, of sodium, of bismuth, of calci