Carl Auer von Welsbach, also known as Carl Auer, Freiherr von Welsbach (1 September 1858 – 4 August 1929) was an Austrian scientist and inventor who had a talent not only for discovering advances, but also for turning them into commercially successful products. He is particularly well known for his work on rare earth elements, which led to the development of the flint used in modern lighters, the gas mantle which brought light to the streets of Europe in the late 19th century, and for the development of the metal filament light bulb.