"The discovery that explosive cotton was soluble in ether, was made
by Mr. Maynard, who gave it the name of Collodion, and later, in
1848, published in the American Journal of Medical Science the
formula for its preparation."
"This ethereal solution, having a certain proportion of alkaline
iodides, and iodides of silver added thereto, constituted the
collodion first employed by Mr. Archer," who thus shares with Mr.
Maynard, and with a Mr. Legray (who first published an account of
its use as a photographic agent) the honor of having given to the
world the collodion process in photography.
The progress that has been made since Mr. Archer's time in
perfecting the adaptability of collodion to photographic uses could
not be better illustrated than by comparing the formulæ for
collodion first published with those in use at this time.
The practice of photography in the present day by the collodion
process is divided into two branches, the positive and the negative.
In the first the object is to obtain in the camera a [p015]
direct image, which is to be viewed by reflected light, and as it is
desired that the pictures so produced should possess pure blacks and
whites, certain modifications of the collodion, silver solution and
developer are resorted to, which cause these preparations to differ
somewhat from those prepared for the production of superior
negatives, consequently the formulæ given hereafter will be
designated as positive or negative.
These modifications, however, are not of such a character as to
render either of the solutions prepared for one process totally
unfit to be used for the other, for in fact, many photographers at
this day use the same collodion bath and developer for making both
positives and negatives.