1. Basic carbonate white lead is a compound of lead, carbon dioxide and water; lead is melted and cast into disks or buckles, which are about six inches in diameter; the buckles are placed in porcelain pots containing dilute acetic acid; the pots are covered with boards and layers of tanbark; heat and carbonic acid generated by fermentation of the tanbark, with the acid vapors, combine to transform the lead into basic carbonate white lead. 2. Basic sulphate white pigment is obtained from lead sulphide ore by a process of fuming or burning. 3. Carter process white lead is made by blowing melted lead in fine granules by a jet of air or superheated steam; the powdered lead is placed in revolving drums or cylinders and subjected to the action of air and carbon dioxide gas from burning coal.