Cadmia

In alchemy, cadmia (Latin for calamine) is an oxide of zinc (tutty) which collects on the sides of furnaces where copper or brass was smelted, and zinc sublimed. The term is also applied to an ore of cobalt.

For the cadmia produced in furnaces, there were five identified kinds: the first called botrytis, as being in the form of a bunch of grapes; the second, ostracitis, as resembling a sea shell; the third, placitis, for resembling a crust; the fourth, capnitis; and the fifth, calamitis, which hung around certain iron rods that were used to stir material in the furnace; being shaken off, the cadmia resembled the figure of a quill, called in the Latin, calamus. The cadmia botrytis was found in the middle of the furnace; the ostrytis at the bottom; the placitis at the top; and the capnitis at the mouth of the furnace.