330	Faraday's Researches
interested by M. Schoenbein's researches, and cannot help
thinking that the peculiar condition of iron which he has
pointed out will (whatever it may depend upon) enable us
hereafter more closely to examine the surface-action of the
metals and electrolytes when they are associated in voltaic
combinations, and so give us a just knowledge of the nature
of the two modes of action by which particles under the influence
of the same power can produce either local effects of combination
or current affinity.1—I am, my dear Phillips, very truly yours,
M.
royal institution, June 16, 1836.
Letter from Mr. faraday to Mr. Bravley on some former Re-
searches relative to the prculiar Voltaic Condition of Iron
r conserved by Professor schoenbein, supplementary to a
Letter to Mr. Phillips, in the last Number?
royal institution, July 8, 1836.
my dear sir,—I am greatly your debtor for having pointed
out to me Sir John F. W. Herschel's paper on the action of
nitric acid on iron in the Annales de Chimie et de Physique:
I read it at the time of its publication, but it had totally escaped
my memory, which is indeed a very bad one now. It renders
one-half of my letter (supplementary to Professor Schoenbein's)
in the last number of the Philosophical Magazine, page 57 (or
page 321 of this volume), superfluous; and I regret only that
it did not happen to be recalled to my attention in time for me
to rearrange my remarks, or at all events to add to them an
account of Sir John Herschel's results. However, I hope the
editors of the PhiL Mag. will allow my present letter a place
in the next number; and entertaining that hope I shall include
in it a few references to former results bearing upon the extra-
ordinary character of iron to which M. Schoenbein has revived
the attention of men of science.
" Bergman relates that upon adding iron to a solution of
silver in the nitrous acid no precipitation ensued." 8
Keir, who examined this action in the year 1790,"* made many
excellent experiments upon it. He observed that the iron
acquired a peculiar or altered state in the solution of silver:
1 Exp. Researches, Pars. 682, 732.
* f.ond. and Edinb. PhiL Mag. 1836, vol. ix. p. 122.
8 PhiL Trans. 1700, p. 374.	4 Tbief. pp. 374 379.