IN last week’s issue your idea of combining silver with a new base in
the collodio-bromide is so good that I think it just as well to mention
that the very notion of acetate of silver has been carried out by me a
dozen years ago, although in another form. I made a collodion for
wet-plate work in which an iodide was used with about an equal part of
acetate of soda; the collodion was accelerated to such a degree that my
exposure was reduced to about a fourth of what I would have given
without the acetate. The plate developed beautifully and free from fog.
Here, again, comes in the law of compensation; my thoroughbred collodion
was, at the end of a dozen hours, as slow as a team of oxen, as vitality
seemed to expend itself in one _coup d’état_, and the second day it was
capital——for cleaning plates.
A bromo-iodised collodion could not be stimulated with any such
exertion. Since practising the collodio-bromide process I have often
promised myself an experiment in this direction; but, somehow or other,
partly from my failure when bromide was in the collodion, the trial has
ended in the intention only.
Mr. Henry Cooper’s success with lactate of ammonia has inspired me with
a strong hope that collodio-bromide is to be the perfection of
“everything to be desired” in dry-plate work.
I am glad to learn that Col. Wortley has found out the conditions of
making a bromised collodion which arrives at maturity without passing
through that infantile existence which I have always regarded as
unfavourable to the best results. When I made the statement in your
Journal, it was from the united experience of all my collodio-bromide
acquaintances, which, if pinned together, would, in respect of mere
lapse of time, extend over the greater part of a century.
Although bromised collodion will give good results when freshly made,
the development of the image is almost a matter of physical force—more
ammonia, more silver, and such like—in order that the excellent prints
expected from your exertions may be superb indeed, in consequence of the
labour bestowed on the negative.
I do not condemn Col. Wortley’s mode of working, for I have lately seen
some of his negatives possessing the very highest qualities attainable
by any process; but, in support of my own recommendation that the
collodion should be left to ripen as a means of lightening our labours
in the dark room, I may state that for over two years I never used
silver as an intensifier, alkaline development giving me always the
right density, and occasionally too much. With an “infant” collodion
silver is the only “soothing syrup” that affords nourishment to the
sickly image.