erefrom; and I have seen many specimens of Daguerreotype very
much injured in effect from this rouge tint disseminated throughout
their shaded features, at the same time that the whole general effect
of such pictures is that of a want of life. It is true that with the
use of rouge a very high degree of polish may be obtained, but probably
not higher than can be produced with many other substances of a less
objectionable nature.

From the announcement of the discovery by Daguerre to the beginning of
the year 1840, I am not aware of any attempt to lessen the time for the
action of an image, or an impression, other than that of the reflecting
camera invented by Mr. Wolcott. Early, however, in 1840, Mr. Wolcott
was desirous to be enabled to further shorten the time for a sitting,
and having some knowledge of bromine and its action, by request, Dr.
Chilton prepared a small quantity; but Mr. Wolcott did not succeed very
well with it, he having invariably used too much in combination with
iodine to produce that sensitive coating now well known to the
profession. Professor Morse, of this city, Dr. Goddard, of
Philadelphia, and others, in the years 1840 and 1841, were acquainted
with the use of bromine. N. Griffing, of this city, or myself, used
with tolerable success, iodine in large excess to nitric acid and
water; and, subsequently, to nitro muriatic acid (which reacted and
formed a peculiar chloride of iodine); this latter combination proved
to be preferable to simple iodine, at the same time somewhat more
sensitive, and was used by me in this city up to the time of my leaving
for London (October 1, 1840). On arriving in London, I instituted a
series of experiments in the various chemical combinations, solely with
the view to be enabled to obtain more speedily a portrait than it was
practicable to do with any known chemicals at that date. The high
latitude, and the winter season of the year rendering but a feeble
light at best, the greater the necessity for a more sensitive chemical
preparation to the shortening the time for a sitting. Near the
beginning of the year 1841, I discovered and practically applied,
chloride of iodine to great advantage, and, as far as memory serves me,
I believe the first used in this country was some made and shipped,
Messrs. Harnden & Co., from London, to Mr. Wolcott, in New York.

About the same time, Mr. John Goddard, of London (who was associated
with myself), discovered a rather valu