117
THE LATE COLONEL RUSSELL'S CONTRIBU-
TIONS TO PHOTOGRAPHY.
By Professor RAPHAEL MELDOLA, F.R.S., F.C.S., &c., Vice-President E.F.C.
[Read November 24th, 1888.]
In the course of preparing a series of lectures on photography, which
I delivered at the Finsbury Technical College during the early part
of the year1, I had occasion to search the literature of this subject,
and was much interested to find how largely we are indebted for the
advancement of modern photography to the work of our late member,
Col. Russell, of Stubbers, of whom an obituary notice has already
been published in the Essex Naturalist (vol. i, p. 139). As an
Essex worthy whose merits as an investigator are so widely known,
both in this country and on the Continent, it seems only a just
tribute to his memory that his labours in the cause of science
should find record in our pages. It is with this object that I
have undertaken to give a brief sketch of his photographic con-
tributions.
Before the introduction of the gelatine dry plates, which are now
so generally used, the process invariably adopted by photographers
was that in which the plate was first coated with a film of collo-
dion, containing a soluble iodide (or bromide and iodide) and
then sensitized by immersion in a silver nitrate bath. The collo-
dion process was first suggested by a Frenchman, Legray, in 1850,
but its practical working out is due to our own countrymen, Scott,
Archer, Fry, and the late Dr. Hugh Diamond, in 1851. There can
be no doubt that the use of collodion marks one of the greatest
epochs in the history of photography and the method thus intro-
duced, for convenience of manipulation and certainty of results, far
transcended any of the older processes. But in these times of rest-
less activity in every department of science, it is not likely that a
process which possessed so many disadvantages should be allowed
to rest without attempts being made to improve upon it or to super-
sede it.
The drawbacks to the old wet collodion process are familiar to
all who have worked at it. The plate had to be coated, sensitized,
1 These lectures have been revised and published as a volume of "Nature Series," under the
title of "The Chemistry of Photography" (Macmillan, 1889).—Ed.
2 His portrait forms a frontispiece to Dr. Eder's "Handbuch der Photographic," vol. i, (Halle,
1834