A complete treatise on the art of retouching photographic negatives : and clear directions how to finish & colour photographs (1898)
Johnson, Robert · London : Marion · leaf 197
i63 AD VER riSEMEN TS MARION'S PYRO-SODA CARTRIDGE DEVELOPER. … TheseTCartridges are made up, one of Pyrogallic Acid, and the other of Sulphite of Soda and Carbonate of Soda in correct proportions. A presei'vative is mixed with this developer to prevent its staining the lingers, as is the case with the ordinary Pyro-Soda Developer. Directions. — Take one each…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from St. Nicholas [serial] (1873)](https://img.insideoutlibrary.com/img/200/ia-stnicholasserial302dodg-244-260.webp)
