atter then dealt with, had associated with it a definite
amount of electrical force, constituting its force of chemical affinity,
the chemical equivalents and the electro-chemical equivalents being the
same (836.). It was also found with few, and I may now perhaps say with no
exceptions (1341.), that only those compounds containing elements in single
proportions could exhibit the characters and phenomena of electrolytes
(697.); oxides, chlorides, and other bodies containing more than one
proportion of the electro-negative element refusing to decompose under the
influence of the electric current.

1708. Probable reasons for these conditions and limitations arise out of
the molecular theory of induction. Thus when a liquid dielectric, as
chloride of tin, consists of molecules, each composed of a single particle
of each of the elements, then as these can convey equivalent opposite
forces by their separation in opposite directions, both decomposition and
transfer can result. But when the molecules, as in the bichloride of tin,
consist of one particle or atom of one element, and two of the other, then
the simplicity with which the particles may be supposed to be arranged and
to act, is destroyed. And, though it may be conceived that when the
molecules of bichloride of tin are polarized as wholes by the induction
across them, the positive polar force might accumulate on the one particle
of tin whilst the negative polar force accumulated on the two particles of
chlorine associated with it, and that these might respectively travel right
and left to unite with other two of chlorine and one of tin, in analogy
with what happens in cases of compounds consisting of single proportions,
yet this is not altogether so evident or probable. For when a particle of
tin combines with two of chlorine, it is difficult to conceive that there
should not be some relation of the three in the resulting molecule
analogous to fixed position, the one particle of metal being perhaps
symmetrically placed in relation to the two of chlorine: and, it is not
difficult to conceive of such particles that they could not assume that
position dependent both on their polarity and the relation of their
elements, which appears to be the first step in the process of
electrolyzation (1345. 1705.).

S 21. _Relation of the electric and magnetic forces._

1709. I have already ventured a few speculations respecting the probable
relation of magnetism, as the transver