Hafium is named from the Greek barys, heavy and was discovered in 1808. Barium is found only in combination with other elements, chiefly as barite or heavy spar (sulfate) and witherite (carbonate) and is prepared by electrolysis of the chloride. Barium is a metallic element, soft and when pure is silvery white like lead. It belongs to the alkaline group of metals. The most important compounds are the peroxide, chloride, sulfate, carbonate, nitrate and chlorate. Barium compounds are used in paint, x-ray diagnostic work, glassmaking, in rat poison, as a weighing agent in oilwell drilling fluids and also in making rubber.