_Mr. Lyte's New Instantaneous Process._--I beg to communicate to you a new
process in photography, which is by far the most rapid I believe yet
discovered, and combines at the same time great stability. It has been the
result of a great many experiments on my part, and even now I am hardly
prepared to say that it is brought to its fullest perfection; but it
suffices to say that it is sufficiently rapid to give pictures of the waves
of the sea in motion with perfect sharpness, and ships sailing at ten knots
an hour, and puttling up and down at the same time, and all with a
landscape lens. By it also, and by the same lens, we may take instantaneous
portraits. The process is as follows:--After the plate, prepared with the
collodion and sensitised with the nitrate bath, as I have described in one
of your former Numbers, is taken from the bath, I pour over it a solution
composed as follows:
1. Take--
Nitrate of silver 200 grains.
Distilled water 6 ounces.
Iodide of silver, as much as will dissolve.
Mix and filter.
2. Take--
Grape sugar or honey 8 ounces.
Water 6 ounces.
Alcohol 1 ounce.
Mix, dissolve, and filter.
And when required for use, mix equal parts of these solutions, and pour
them over the plate. The plate is to be allowed to drain; and then, when
placed in the frame, is ready for the camera, and is easily impressed as a
deep negative by a Ross's landscape lens instantaneously. To develop, I use
always the same agents as I have before specified. One or two cautions are
to be observed in this process. First, the grape-sugar or honey must be
quite pure, and free from any _strong_ acid re-action; and, secondly, these
substances are much improved by a long exposure to the air, by which the
oxidation of them is commenced, and the result made much more certain and
effective. However, I find that the addition of the least possible quantity
of nitric acid has the same effect; but nothing is so good as long exposure
of the sugar or honey, so as to become completely candied before mixing.
The sugar may as conveniently of course be mixed in the collodion as in the
bath, but in that case the keeping properties are lost, as the plate is not
thus kept longer moist than usual. If, however, the former process be used
and well conducted, the plate when sensitised may be kept for four hours at
least without injury.
The grape sugar should be made with oxalic, and the acid removed by lime as
usual, and not with sulphuric acid, as is often done; as in the latter case
sulpho-saccharic acid is formed, which much injures the result.
I have been trying numerous experiments in this line, and I think I have
almost hit upon another and quite new and instantaneous process; but as it
is only in embryo, I will not give it to you till perfect. There are of
course many other substances to be yet mixed in the bath or the collodion,
_e. g._ all the alkaloids, or indeed any of the deoxidating agents known,
and probably with good results. I am still continuing my experiments on
this head, and if I make any farther improvements I will lose no time in
communicating them to you. Some negatives taken by this means were
exhibited on Friday evening at the Royal Institution, and were much
admired.