Carl GraebeDied 19 Jan 1927 at age 85 (born 24 Feb 1841).German organic chemist who, assisted by Carl Liebermann, synthesized (1868) the orange-red dye alizarin, which in the textile industry quickly supplanted the natural source of the dye from the madder plant root. Alizarin (dihydroscyanthraquinone) was recognized by Graebe and Liebermann, as a derivative of anthracene, a hydrocarbon contained in coal-tar. Also in 1868, they elaborated a method for preparing it commercially from anthracene. Upon this, one of the early German dyestuff products, arose rapidly a great chemical industry. Graebe also introduced the chemical terms "ortho," "meta," and "para," well known to organic chemistry students, which indicate the position of groups attached to a benzene ring.