CHAPTER V. METALLIC COMPOUNDS 32 Alkalis.—Potassium Compounds—Potassium Carbonate —Potassium Hydroxide—Potassium Nitrate—Potassium Bitartrate—Potassium Bichromate—Potassium Sodium Chromate—Chrome Alum—Potassium Ferrocyanide —Potassium Ferricyanide—Sodium Salts—Sodium Carbonate—Sodium Hydroxide—Sodium Thiosulphate —Sodium Chloride—Salts of the Alkaline Earth Metals. Calcium Compounds.—Calcium Oxide—Calcium Hydroxide —Calcium Carbonate—Calcium Sulphate—Calcium Phosphate —Magnesium Carbonate—Barium Compounds—Barium Chloride. Aluminium Compounds—Aluminium Sulphate. The Alums.—Potassium Aluminium Alum—Roman Alum—Soda Alum—Ammonia Alum—Alumina and Hydrate of Alumina. Compounds of the Heavy Metals.—Zinc Compounds—Cadmium Compounds—Iron Compounds—Ferrous Sulphate—Ferrous Chloride—Manganese Compounds—Nickel Compounds—Cobalt Compounds—Chromium Compounds—Molybdenum, Tungsten and Vanadium Compounds—Antimony Compounds—Bismuth Compounds —Tin Compounds—Arsenic Compounds—Lead Compounds —Lead Sulphate—Lead Nitrate—Lead Acetate—Basic Lead Acetate—Lead Chloride—Copper Compounds—Copper Sulphate —Copper Nitrate—Copper Acetate—Mercury Compounds —Mercurous Nitrate—Mercuric Nitrate—Mercurous Chloride —Mercuric Chloride—Silver Compounds—Gold Compounds. CHAPTER VI. THE MANUFACTURE OF MINERAL PIGMENTS 71 White Mineral Pigments—White Lead. CHAPTER VII. THE MANUFACTURE OF WHITE LEAD 77 Manufacture of White Lead from Metallic Lead.—Dutch Process: Casting the Lead into Sheets—Building up the Stacks—Removal and Grinding of the White Lead—White Lead Mills—Hard White Lead—Soft White Lead.—German Process.—French Process: Preparation of the Solution of Basic Lead Acetate—Preparation of the Carbonic Acid and Precipitation of the White Lead—Manufacture of White Lead by Means of Natural Carbonic Acid.—English Process.—Other Methods. —Oxychloride White Lead: Lead Sulphite—Lewis & Bartlett’s White Lead Pigment.—White Lead -Antimony Pigments: Lead Antimonite—Lead Antimonate. CHAPTER VIII. ENAMEL WHITE 116 Lithopone. CHAPTER IX. WASHING APPARATUS 120 Filter Presses.