[welz-bak, -bahk; Germanvels-bahkh] /ˈwɛlz bæk, -bɑk; German ˈvɛls bɑx/ Show IPA
a brand of gaslight consisting essentially of a Bunsen burner on which an incombustible mantle (Welsbach mantle) composed of thoria and some ceria becomes brilliantly incandescent when exposed to flame.
Welsbach burner (ˈwɛlzbæk, German ˈvɛlsbax)
trademark a type of gaslight in which a mantle containing thorium and cerium compounds becomes incandescent when heated by a gas flame
[C19: named after Carl Auer, Baron von Welsbach (1858--1929), Austrian chemist, who invented it]