An old alchemical sign for alum or alumen.
Alum is a double sulfate of ammonium and a univalent metal (such as sodium or potassium), or of ammonium and a trivalent metal (such as aluminum, iron, or chromium). It is used as an astringent, an emetic and in the manufacture of baking powders, dyes, and paper.
Category: Alchemical Symbols.
More symbols in Alchemical Symbols:
Alchemical symbols, originally devised as part of alchemy, were used to denote some elements and some compounds until the 18th century. Note that while notation like this was mostly standardized, sty… read more »