Calx
Residual substance, sometimes in the form of a fine powder / From Wikipedia, the free encyclopedia
Calx is a substance formed from an ore or mineral that has been heated.[1] Calx, especially of a metal, is now understood to be an oxide. The term is also sometimes used in older texts on artists' techniques to mean calcium oxide. [citation needed]
This article needs additional citations for verification. (September 2018) |
According to the obsolete phlogiston theory, the calx was the true elemental substance that was left after phlogiston was driven out of it in the process of combustion.[2]