Praseodymium was discovered in 1885 by the German chemist Carl F. Auer von Welsbach. Praseodymium is a yellowish metal that tarnishes easily. Praseodymium salts are generally green in color. Praseodymium liberates hydrogen when in contact with water. It is soluble in dilute acids, paramagnetic and is considered nontoxic. ESPI produces a variety of finished praseodymium products including rod, wire, foil, sheet, pieces and powder. Due to praseodymium's sensitivity to oxygen the finished product is packaged under dry argon in sealed metal cans.