“We find Theophrastus (315 B.C.) describing... the manufacture of white lead... "lead is placed in an earthen vessel over sharp vinegar, and after it has acquired some thickness of a kind of rust... they open the vessels and scrape it off. ...repeating over and over again... til it is wholly gone. What has been scraped off they then beat to a powder and boil with water for a long time, and what at last settles to the bottom is white lead.”