Iodide Ammonium 192 grains
Bromide Cadmium 128 "
Bromide Potassium 96 "
Ether and Alcohol 32 oz. each
Cotton 320 grains
The preceding formulæ are for portrait work in studio. For other
work, such as outdoor views, [p028] landscape or architectural,
or for copying engravings, etc., certain modifications of the
collodion, to produce greater intensity or more contrast, are
desirable. Collodion suitable for such purposes can always be
purchased from the photo stock dealer, in quantities desired, and
for that reason it is not best for the amateur nor the professional
photographer either, to prepare small samples for special purposes.
If it should, however, be found at any time necessary to prepare
such a collodion, the second formula of Negative Collodion A will be
found suitable for views of buildings, copies of engravings and such
like work.
It was at first thought to be unnecessary to give a formula for the
preparation of pyroxiline or gun cotton, as no individual not in the
business can possibly produce an article that can be in any way
compared to that made by manufacturers of skill and experience.
For the benefit of any one wishing to experiment, this formula is
given: