Welsbach, Carl Auer, Baron von Welsbach (1858-1929)

Austrian chemist and engineer who discovered two rare-earth elements and invented the incandescent gas mantle and a lighter flint.

Auer was born in Vienna and studied in Germany at Heidelberg.

He showed that didymium, previously thought to be an element, actually consisted of two very similar but different elements: praseodymium and neodymium. He also found that another rare earth element, cerium, added as its nitrate salt to a cylindrical fabric impregnated with thorium nitrate, produced a fragile mantle that glowed with white incandescence when heated in a gas flame. The ‘Welsbach mantle’ was patented 1885.

Most lighter flints consist of Welsbach's invention Mitschmetall, a pyrophoric mixture containing about 50% cerium, 25% lanthanum, 15% neodymium, and 10% other rare metals and iron. When it is struck or scraped, it produces hot metal sparks. Mitschmetall is also used as a deoxidizer in vacuum tubes and as an alloying agent for magnesium.