meaning to dismiss
metallic contact, or the contact of dissimilar substances, being
conductors, but not metallic, as if they had nothing to do with the origin
of the current,

I still am fully of opinion with Davy, that it is at least continued by
chemical action, and that the supply constituting the current is almost
entirely from that source.

858. Those bodies which, being interposed between the metals of the voltaic
pile, render it active, _are all of them electrolytes_ (476.); and it
cannot but press upon the attention of every one engaged in considering
this subject, that in those bodies (so essential to the pile) decomposition
and the transmission of a current are so intimately connected, that one
cannot happen without the other. This I have shown abundantly in water, and
numerous other cases (402. 476.). If, then, a voltaic trough have its
extremities connected by a body capable of being decomposed, as water, we
shall have a continuous current through the apparatus; and whilst it
remains in this state we may look at the part where the acid is acting upon
the plates, and that where the current is acting upon the water, as the
reciprocals of each other. In both parts we have the two conditions
_inseparable in such bodies as these_, namely, the passing of a current,
and decomposition; and this is as true of the cells in the battery as of
the water cell; for no voltaic battery has as yet been constructed in which
the chemical action is only that of combination: _decomposition is always
included_, and is, I believe, an essential chemical part.

859. But the difference in the two parts of the connected battery, that is,
the decomposition or experimental cell, and the acting cells, is simply
this. In the former we urge the current through, but it, apparently of
necessity, is accompanied by decomposition: in the latter we cause
decompositions by ordinary chemical actions, (which are, however,
themselves electrical,) and, as a consequence, have the electrical current;
and as the decomposition dependent upon the current is definite in the
former case, so is the current associated with the decomposition also
definite in the latter (862. &c.).

860. Let us apply this in support of what I have surmised respecting the
enormous electric power of each particle or atom of matter (856.). I showed
in a former series of these Researches on the relation by measure of common
and voltaic electricity, that two wires, one of platina