A practical manual of photography : containing full and plain directions for the economical production of really good daguerreotype portraits, and every other variety of photographic pictures according to the latest improvements, also the injustice and validity of the patent considered, with suggestions for rendering a such patent a virtual dead letter, etc. (1845)
Hogg, Jabez, 1817-1899 · London : E. Mackenzie · leaf 64
found that a darkening action will gradually come on, and eventually devolope the picture, which may be impressed on the paper. This process is much quickened by placing the paper in cold water. Chloride of gold with nitrate of silver gives a precipitate of a yellow brown colour, possibly metallic…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
