the "deutsche gasglühlicht ag" (degea, german gas light company), was founded in 1892 through the combined efforts of the jewish entrepreneur and banker geheimrat (privy councillor) leopold koppel and the austrian chemist and inventor carl auer von welsbach. it was the forerunner of "auergesellschaft". their main research activities, up to the close of world war ii, were on gas mantles, luminescence, rare earths, radioactivity, and on uranium and thorium compounds.