Liver of sulfur
Liver of sulfur is a loosely defined mixture of potassium sulfide, potassium polysulfide, potassium thiosulfate, and likely potassium bisulfide. Synonyms include hepar sulfuris, sulfur, sulfurated potash and sulfurated potassa. There are two distinct varieties: "potassic liver of sulfur" and "ammoniacal liver of sulfur".[1]
Overview
Liver of sulfur is mainly used in
The highest quality liver of sulfur in solid form is a dark yellow, almost "liver" colored substance. As it ages and is exposed to air, its potency decreases, it will turn lighter yellow and finally white, at which point its reactivity is negligible.
The reactivity of liver of sulfur with silver and copper quickly creates a dark or colored patina on the metal. This is done by immersing the metal object in a solution of liver of sulfur and water. When treating silver, the solution must be hot, though if the bath is brought to its boiling point the liver of sulfur will quickly decompose and become ineffective. Also, if the concentration of the solution is too strong, the oxidation process will proceed too quickly and the layer of patina thus created will tend to flake away. The best results are usually obtained by using more dilute solutions and allowing the patina to build more slowly but more securely, and, for silver, keeping the solution just under its boiling point. Lastly, it is critical that the metal surface be extremely clean, as clean as would be necessary to
Medical use
Liver of sulfur was once used to counteract poisoning with several metals, including arsenic, copper, lead, and antimony. A lump was dissolved in warm water and the patient was instructed to drink the solution three or four times over the course of an hour.[3] At one time sulfurated potash was used to combat arthritis. It eventually fell into disfavor for medical purposes because sulfides and polysulfides were discovered to be toxic in their own right.
References
- ^ Leopold Gmelin (1852). Hand-book of Chemistry: Metals - (concluded). Cavendish Society. p. 21.
- ^ a b c Platers' Guide: With which is Combined Brass World. Brass world publishing Company, Incorporated. 1905. p. 308.
- ^ Richard Reece (1833). The Medical Guide ... The fourteenth edition, with additions. p. 182.