lso apply it to the surfaces of air (465.
471.) and water (493.), against which I have effected electro-chemical
decomposition, is subject to doubt. In place of the term pole, I propose
using that of _Electrode_[A], and I mean thereby that substance, or rather
surface, whether of air, water, metal, or any other body, which bounds the
extent of the decomposing matter in the direction of the electric current.

[A] [Greek: elektron], and [Greek: -odos] _a way_.

663. The surfaces at which, according to common phraseology, the electric
current enters and leaves a decomposing body, are most important places of
action, and require to be distinguished apart from the poles, with which
they are mostly, and the electrodes, with which they are always, in
contact. Wishing for a natural standard of electric direction to which I
might refer these, expressive of their difference and at the same time free
from all theory, I have thought it might be found in the earth. If the
magnetism of the earth be due to electric currents passing round it, the
latter must be in a constant direction, which, according to present usage
of speech, would be from east to west, or, which will strengthen this help
to the memory, that in which the sun appears to move. If in any case of
electro-decomposition we consider the decomposing body as placed so that
the current passing through it shall be in the same direction, and parallel
to that supposed to exist in the earth, then the surfaces at which the
electricity is passing into and out of the substance would have an
invariable reference, and exhibit constantly the same relations of powers.
Upon this notion we purpose calling that towards the east the _anode_[A],
and that towards the west the _cathode_[B]; and whatever changes may take
place in our views of the nature of electricity and electrical action, as
they must affect the _natural standard_ referred to, in the same direction,
and to an equal amount with any decomposing substances to which these terms
may at any time be applied, there seems no reason to expect that they will
lead to confusion, or tend in any way to support false views. The _anode_
is therefore that surface at which the electric current, according to our
present expression, enters: it is the _negative_ extremity of the
decomposing body; is where oxygen, chlorine, acids, &c., are evolved; and
is against or opposite the positive electrode. The _cathode_ is that
surface at which the curre