A rare pair of antique apothecary jars in jet black amethyst glass.
Sunlight accelerates oxidation and can promote the breakdown of many chemical compounds, making dark glass a desirable quality in apothecary jars. The dark tints are made by adding various salts, chromium oxide (green) cobalt (blue) and gold or selenium (red). Amber is common and progressively less so greens, blues, reds and purples. Most dark glass when held up to the light will usually reveal its base colour.
These jars are pitch black which in the early 19th century required the addition of manganese, cobalt and iron and was not easy to acheive. Relatively few were made, making them now hard to find and much sought after. The mushroon shaped stoppers have a beautiful and striking starburst design which has been painstakingly cut by hand. The pontils are smooth and polished.
Kalium Iodatum was used in mercurial, syphilitic, and scrofulous affections. Also in secondary syphilis, especially after abuse of Mercury or combined with scrofula, buboes and chancres. Kalico Silver Nitrate may have been used a dye for printing on silk and animal materials.
[Apothecarial demands aside, clear glass was the order of the day in the late 19th century. The iron in sand gave most early clear glass a light green to an amber tint. As an alternative to the expensive use of lead to produce clear lead crystal, factories using iron-bearing sands from started to add manganese to their batch as a decolorizer from around 1880. This produced a clearer glass, but which turned a light purple or amethyst color when exposed to sunlight].