This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
White powder; blackens on exposure to light. Soluble in solutions of ammonium, potassium hyposulphite and in potassium cyanide. Used largely in the sensitizing emulsions of the various printing-out processes, owing to its properties of darkening on exposure to light.
(See Intensification, Silver.)
Light yellow powder; odorless; tasteless; affected by light. Soluble in potassium iodide or potassium cyanide; also in ammonium hyposulphite. Insoluble in water and alcohol. Used in various sensitive emulsions and is extremely sensitive to light and gives a dense image.
AgNO3 - II; VII.
Nitrate of Silver, Argentic Nitrate, Lunar Caustic. Colorless, rhombic plates; odorless; bitter, caustic, metallic taste; rapidly reduced by organic matter in light. Soluble in about I part water, 26 parts alcohol, 0.1 part boiling water and 5 parts boiling alcohol. May be prepared by dissolving pure silver in nitric acid. Six ounces of silver are dissolved in 2 1/2 ounces of strong nitric acid and 10 ounces of water, the solution being generally heated, after which it is evaporated to dryness and heated to 198o Cent., to expel any excess of acid. Used extensively in photography, but especially to form other silver salts.
A print made on paper which has been sensitized with an emulsion containing silver salts.
A term used to designate the substance formed by the action of light upon silver bromide.
A term used to designate the substance formed by the action of light upon silver chloride.
A term used to designate the substance formed by the action of light upon silver iodide.
A term used to designate the substance formed by the action of light on the various salts of silver, such as silver bromide, chloride and iodide, the sub-salts being termed silver sub-bromide, sub-chloride and sub-iodide. These sub-salts are simply hypothetical substances, as it has never been possible to analyze them sufficiently to establish their chemical individuality.
Grayish-black, heavy powder. The resultant salt of the decomposition of silver hyposulphite in prints. Soluble in nitric acid, which latter converts it into silver sulphite and silver nitrate; insoluble in water or ammonia.
Soluble silver salts will give a white precipitate which is soluble in ammonia when placed in hydrochloric acid, while a brick-red precipitate will result when placed in potassium chromate; sulphuretted hydrogen gives a black precipitate.