First uses thumb|alt=Gas mantle|World War II thorium dioxide gas mantle While thorium was discovered in 1828 its first application dates only from 1885, when Austrian chemist Carl Auer von Welsbach invented the gas mantle, a portable source of light which produces light from the incandescence of thorium oxide when heated by burning gaseous fuels. Many applications were subsequently found for thorium and its compounds, including ceramics, carbon arc lamps, heat-resistant crucibles, and as catalysts for industrial chemical reactions such as the oxidation of ammonia to nitric acid.
First uses thumb|alt=Gas mantle|World War II thorium dioxide gas mantle While thorium was discovered in 1828 its first application dates only from 1885 when Austrian chemist Carl Auer von Welsbach invented the gas mantle a portable source of light which produces light from the incandescence of thorium oxide when heated by burning gaseous fuels Many applications were subsequently found for thorium and its compounds including ceramics carbon arc lamps heat-resistant crucibles and as catalysts for industrial chemical reactions such as the oxidation of ammonia to nitric acid