Barium
a dyad netallic element; symbol Ba; atomic weight, 137. Barium is prepared by the decomposition of barium chloride, BaCl2, by the electric current, or by the vapor of potassium. It is a white, malleable metal, which melts at red heat, decomposes water, and oxidizes in the air. Bariu occurs in nature as barium carbonite and sulphate. Its salts are prepared by dissolving the carbonate in acids, or by roasting the native sulphate of barium with one-third its weight of coal, which converts it into barium sulphide, BaS; this is decomposed by hydrochloric or nitric acid, according as a chloride or nitrate of barium is required.
All soluble salts of barium are very poisonous; the best antidotes are alkaline sulphates. The salts of barium are employed as re-agents in the laboratory, and in the manufacture of fireworks, to produce a green light.