332 Faraday's Researches

having been anticipated by Sir John Herschel,, and also much
of what relates to the action of silver and iron, as having been
formerly recorded by Keir. The facts relating to gold and
carbon in association with iron; the experimental results as to
the electric currents produced; the argument respecting the
chemical source of electricity in the voltaic pile; and my opinion
of the cause of the phenomena as due to a relation of the super-
ficial particles of the iron to oxygen., are what remain in the
character of contributions to our knov/ledge of this very beautiful
and important case of voltaic condition presented to us by the
metal iron.—I am, my dear Sir; yours very truly,

M. FARADAY.
E. W, Bmyley, Esq.
London Institution*tes ol