Nils Sefstrom
^BNils Sefstrom.^b Portrait of Nils Gabriel Sefstrom, Swedish chemist and physician (1787-1845). In 1831 he discovered the metal ^Ivanadium^i which can be used to strengthen steels and in high-temperature tools. Sefstrom was professor at the Caroline Institute of Medicine and Surgery, and at the School of Mines in Stockholm.