ON THE PROBABILITY OF PRODUCING COLORED PICTURES BY THE SOLAR
RADIATIONS--PHOTOGRAPHIC DEVIATIONS--LUNAR PICTURES--DRUMMOND LIGHT.
Having before noticed the fact that some advances had been made towards
taking Daguerreotypes in color, by means of solar rays, and expressed
the hope that the day was not far distant when this might be
accomplished, I here subjoin Mr. Hunt's remarks on this subject.
Mr. Biot, in 1840, speaking of Mr. Fox Talbot's beautiful calotype
pictures, considers as an illusion "the hope to reconcile, not only the
intensity but the tints of the chemical impressions produced by
radiations, with the colors of the object from which these radiations
emanated." It is true that three years have passed away, and we have
not yet produced colored images; yet I am not inclined to consider the
hope as entirely illusive.
It must be remembered that the color of bodies depends entirely upon
the arrangement of their molecules. We have numerous very beautiful
experiments in proof of this. The bi-niodide of mercury is a fine
scarlet when precipitated. If this precipitate is heated between
plates of glass, it is converted into crystals of a fine sulphur
yellow, which remain of that color if undisturbed, but which becomes
very speedily scarlet if touched with any pointed instrument. This
very curious optical phenomena has been investigated by Mr. Talbot and
by Mr. Warrington. Perfectly dry sulphate of copper is white; the
slightest moisture turns it blue. Muriate of cobalt is of a pale pink
color; a very slight heat, by removing a little moisture, changes it to
a green. These are a few instances selected from many which might be
given.
If we receive a prismatic spectrum on some papers, we have evidence
that the molecular or chemical disturbance bears some relation to the
color of each ray, or, in other words, that colored light so modifies
the action of ENERGIA that the impression it makes is in proportion to
the color of the light it accompanies, and hence there results a
molecular arrangement capable of reflecting colors differently. Some
instances have been given in which the rays impressed correspond with
the colors of the luminous rays in a very remarkable manner.* One of
the most decided cases is that of the paper prepared with the fluoride
of soda and nitrate of silver. Sir John Herschel was, however, the
first to obtain any good specimens of photographically impressed
prismatic colorations.
* See Mr. Hunt's "Researches on Light."
It was noticed by Daguerre that a red house gave a reddish image on his
iodized silver plate in the camera obscura; and Mr. Talbot observed,
very early in his researches, that the red of a colored print was
copied of a red color, on paper spread with the chloride of silver.**
** In 1842, I had shown me a picture of a house in the Bowery, which
had been repaired a few days previous, and in the wall a red brick
left. This brick was brought out on the Daguerreotype plate of
precisely the same color as the brick itself. The same artist also
exhibited to me, the full length portrait of a gentleman who were a
pair of pantaloons having a blue striped figure. This blue stripe was
fully brought out, of the same color, in the picture.--AMER. ED.
"In 1840 I communicated to Sir John Herschel some very curious results
obtained by the use of colored media, which he did me the honor of
publishing in one of his memoirs on the subject from which I again copy
it."
"A paper prepared with muriate of barytes and nitrate of silver,
allowed to darken whilst wet in the sunshine to a chocolate color, was
placed under a frame containing a red, a yellow, a green, and a blue
glass. After a week's exposure to diffused light, it became red under
the red glass, a dirty yellow under the yellow glass, a dark green
under the green, and a light olive under the blue.
"The above paper washed with a solution of salt of iodine, is very
sensitive to light, and gives a beautiful picture. A picture thus
taken was placed beneath the above glasses, and another beneath four
flat bottles containing colored fluids. In a few days, under the red
glass and fluid, the picture became a dark blue, under the yellow a
light blue, under the green it remained unchanged, whilst under the
blue it became a rose red, which in about three weeks changed into
green. Many other experiments of a similar nature have been tried
since that time with like results.
"In the summer of 1843, when engaged in some experiments on papers
prepared according to the principles of Mr. Talbot's calotype, I had
placed in a camera obscura a paper prepared with the bromide of silver
and gallic acid. The camera embraced a picture of a clear blue sky,
stucco-fronted houses, and a green field. The paper was unavoidably
exposed for a longer period than was intended--about fifteen
minutes,--a very beautiful picture was impressed, which, when held
between the eye and the light, exhibited a curious order of colors.
The sky was of a crimson hue, the houses of a slaty blue, and the green
fields of a brick red tint. Surely these results appear to encourage
the hope, that we may eventually arrive at a process by which external
nature may be made to impress its images on prepared surfaces, in all
the beauty of their native coloration."