Barium bromide and can cause severe poisoning if ingested. Barium bromide Barium bromide is the chemical compound with the formula BaBr. Like barium chloride, it dissolves well in water and is toxic in aqueous solution. BaBr crystallizes in a lead chloride motif, giving white orthorhombic crystals which are deliquescent. In aqueous solution BaBr behaves as a simple salt. Barium bromide reacts with the sulfate ion from sulfuric acid to produce a precipitate of barium sulfate. Similar reactions occur with oxalic acid, hydrofluoric acid, and phosphoric acid. Barium bromide can be prepared from barium sulfide or barium carbonate via reaction with hydrobromic acid
Calamine brass Calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even though the alloyed calamine brass was in use for centuries, and metallic zinc was produced directly via reducing-atmosphere smelting in India and China from the 12th century CE onwards. Brass is an alloy of copper and zinc and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists wishing to produce brass thus used calamine (actually