to produce carbon prints by means of photography.[1] The earliest examples exhibited were shown at the April meeting of the London Photographic Society, in 1858: but the author declined to describe the process. An allusion to it and its results, without details, had appeared in one of the journals a few weeks earlier, viz:
“He prepared the paper, or other surface, for having the picture produced on it, by applying over its whole surface the coloring matter which formed the picture, and together with this coloring matter applied a substance which is acted on by the light. The following is the manner in which he proceeded when printing positive pictures on paper from negative pictures: He coated the paper, or surface which received the picture, with a composition of vegetable carbon, gum arabic, and bichromate of potash, and on to this prepared surface placed the negative picture, and exposed it to the light in the usual way. Afterwards, the surface was washed with water, which dissolved the composition at the parts on which the light had not acted, but failed to affect those parts of the surface on which the light had acted. Consequently, on those parts of the surface the coloring matter remained in the state in which it was applied, having experienced no chemical change. Sometimes, for the vegetable carbon, he substituted bitumen.”
MM. Henri Gamier and Alphonse Salmon, in August, 1858, laid before the French Photographic Society, a “Method of Carbon Printing,” in which paper was treated with a strong solution of citrate of iron, and after drying in the dark, was exposed under a transparent positive. The parts acted upon by light were rendered insoluble, whilst the parts protected by the dense portions of the cliché remained soluble and hygroscopic; and
- ↑ It is right to place on record here that this has been denied. Mr. Portbury, in a letter to the Photographic News, Nov. 23, 1860, and personally at a meeting of the Photographic Society, Nov. 4, 1862, claimed the production of the first carbon prints, stating that he was at the time an apprentice with Mr. Pouncy.
