referred.

_Royal Institution,
November 30, 1833._

SEVENTH SERIES.

S 11. _On Electro-chemical Decomposition, continued._[A] P iv. _On some
general conditions of Electro-decomposition._ P v. _On a new Measurer of
Volta-electricity._ P vi. _On the primary or secondary character of bodies
evolved in Electro-decomposition._ P vii. _On the definite nature and
extent of Electro-chemical Decompositions._ S 13. _On the absolute quantity
of Electricity associated with the particles or atoms of Matter._

[A] Refer to the note after 1047, Series VIII.--_Dec. 1838._

Received January 9,--Read January 23, February 6 and 13, 1834.

_Preliminary._

661. The theory which I believe to be a true expression of the facts of
electro-chemical decomposition, and which I have therefore detailed in a
former series of these Researches, is so much at variance with those
previously advanced, that I find the greatest difficulty in stating
results, as I think, correctly, whilst limited to the use of terms which
are current with a certain accepted meaning. Of this kind is the term
_pole_, with its prefixes of positive and negative, and the attached ideas
of attraction and repulsion. The general phraseology is that the positive
pole _attracts_ oxygen, acids, &c., or more cautiously, that it
_determines_ their evolution upon its surface; and that the negative pole
acts in an equal manner upon hydrogen, combustibles, metals, and bases.
According to my view, the determining force is _not_ at the poles, but
_within_ the body under decomposition; and the oxygen and acids are
rendered at the _negative_ extremity of that body, whilst hydrogen, metals,
&c., are evolved at the _positive_ extremity (518. 524.).

662. To avoid, therefore, confusion and circumlocution, and for the sake of
greater precision of expression than I can otherwise obtain, I have
deliberately considered the subject with two friends, and with their
assistance and concurrence in framing them, I purpose henceforward using
certain other terms, which I will now define. The _poles_, as they are
usually called, are only the doors or ways by which the electric current
passes into and out of the decomposing body (556.); and they of course,
when in contact with that body, are the limits of its extent in the
direction of the current. The term has been generally applied to the metal
surfaces in contact with the decomposing substance; but whether
philosophers generally would a