For many centuries, this highly toxic substance was actually used as a cosmetic. Dating at least far back as Mycenaean-era Greece (roughly 1600-1100 B.C.E.), it continued to be used in this capacity right up though the early modern era. Queen Elizabeth I of England, for example, began wearing make-up of this substance to help conceal her facial scars, remnants of a case of smallpox she contracted in 1562.