ABSTRACT
The term metal is in use without the possibility of a strict definition. Seven metals were distinguished by the ancients and were in alchemical times associated in a fantastic manner with the names of the seven “planets.” Of these names Sol (gold), Luna (silver), Mercury (quicksilver), Venus (copper), Mars (iron), Jupiter (tin), Saturn (lead), only one, namely Mercury, has been retained in common use. Electric current is obtainable at moderate expense, and sodium is made in large quantity by the electrolysis of caustic soda fused and kept at a temperature about 20° C. above its melting point. Aluminium is probably the most abundant metallic element in the earth, as in the form of the oxide, alumina A1203, it is the chief constituent of many crystalline rocks and of all clays. Aluminium has been manufactured for many years by submitting to electrolysis alumina (prepared bauxite) dissolved in fused cryolite, the double fluoride of aluminium and sodium.
