_100, Clarendon-road, Notting-hill, January 29, 1872._
NATURAL COLOURS IN PHOTOGRAPHY.
_To the_ EDITORS.
GENTLEMEN,—Last night, as “I lay a-thinking,” the subject of obtaining
photographic colour suddenly occurred to me, and the question arose as
to whether the differences in the colours of the light reflected from
the surfaces of different-coloured flowers (as red, blue, and yellow)
was due to differences in the constitution of their juices, or of the
solid matter of which they are formed. If on examination it proved to be
of the juices, a second question arose as to whether it would not be
possible to take advantage of this in the preparation of plates, as
suggested by me in an article which you inserted in THE BRITISH JOURNAL
OF PHOTOGRAPHY for October 27, 1865 (No. 286, vol. xii.). Then,
supposing that by this or any other means the three monochromic plates
were obtainable, would coloured glasses placed in front of the lens help
to stop off the colours not to be represented on the plate? Thus, with a
plate sensitive to blue only, the interposition of a blue glass would
prevent the transmission of the yellow and red rays, a red glass those
of the blue and yellow rays, and a yellow glass that of the blue and red
rays to the plates sensitive to the blue, red, and yellow rays
respectively.
I have evidence that so early as 1842 the late Sir John Herschel
obtained variously-coloured photographs on paper, as he gave me several,
and I have still one a good blue, one a fair red, and two purple. The
letter accompanying them describes the two latter as produced by the use
of the juice of the red poppy; but many of them have faded away
entirely. My impression is that others of them were from vegetable
juices, but I am not sure that this was the case. There can be no doubt,
however, that his published papers will give an account of the numerous
experiments he made on this subject.
These suggestions may, or may not, be of value in forwarding the
realisation of the great _desideratum_ of photographic colour; but I
cannot be far wrong in mentioning them as they occur to me, especially
as my former communication, in 1865, was thought to be worth
consideration by experimentalists.
That the great end will be attained before a very long period has
elapsed, and the prediction of M. Niepce be verified, that “one day a
photographic picture will be produced such as one sees in a
looking-glass,” is the hope and wish of—Yours, &c.,