from The Century Dictionary.
- noun In photography: A photographic process in which paper sensitized by ferric ammonium citrate is exposed behind a negative and the picture is developed by a neutral solution of gold chlorid and fixed by potassium iodide. The process is due to Sir John Herschel.
- noun A picture made by this process.
from the GNU version of the Collaborative International Dictionary of English.
- noun A photographic picture taken upon paper prepared by the use of a sensitive salt of iron and developed by the application of chloride of gold.
- noun 2process, invented by Sir J.Herschel.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun A
photographtaken on paperprepared by the use of a sensitive saltof ironand developedby the application of gold chloride.
from Wiktionary, Creative Commons Attribution/Share-Alike License
The following process, discovered at the same time as the cyanotype, and termed chrysotype, is thus described by Sir John Herschel:
As the chrysotype will be no more referred to, we shall state, first, that the image can be developed with a plain solution of silver nitrate or one acidified with citric or any other organic acid, which generally gives a brown impression that can be toned with an acid or alkaline gold bath, the color varying with the solution employed; and secondly, that the process may be employed to obtain outlines of any picture on paper or canvas to be colored in oil-paints.
“In point of _direct_ sensibility, the chrysotype paper is certainly inferior to the calotype; but it is one of the most remarkable peculiarities of gold as a photographic ingredient, that _extremely feeble impressions once made by light go on afterwards, darkening spontaneously and very slowly, apparently without limit so long as the least vestige of unreduced chloride of gold remains in the paper_.
“If paper prepared as above recommended for the chrysotype, either with the ammonio-citrate or ammonio-tartrate of iron, and impressed, as in that process, with a latent picture, be washed with nitrate of silver instead of a solution of gold, a very sharp and beautiful picture is developed of great intensity.