N Neutralization, example of, 4 ——, explanation of, 3 Niagara, 101 Nitre, 29 —— pots, 14 Nitric acid, 30 —— ——, from air, 40 —— ——, importance of, 28 —— —— manufacture of, 30 —— ——, properties, 31 —— ——, red fuming, 31 —— oxide, 16 Nitrogen cycle, 37 ——, fixation of, 100 —— peroxide, 16 Nitroglycerine, 34 O Olein, 78 Onyx, 61 Opal, 61 Orthoclase, 62 Oxalic acid, 77 P Palmitin, 78 Pearls, 51 Peregrine Phillips, 21 Philosopher’s stone, 2 Phosphoric acid, 57 Plaster of Paris, 27 Potash, caustic, 97 ——, mild, 93 Potassium, 95 —— bicarbonate, 94 —— nitrate, 29 Propellants, 33 Prussian blue, 25 Pyrites burners, 14 Pyroligneous acid, 73 Q Quartz, 61 —— fibres, 62 ——, smoky, 61 Quicklime, 5, 51 R Red liquor, 73 Rock crystal, 61 Rupert’s drops, 65 S Sal ammoniac, 99 —— prunella, 29 Salt cake, 84 ——, common, 47 ——, formation of a, 4 Saltpetre, 29 Salts, from carbonates, 5 ——, from oxides, 5 ——, from metals, 4 ——, insoluble, 6 Sandstone, artificial, 66 Saponification, 79 Schweinfurt green, 27 Shells, egg, 51 ——, oyster, 51 Silica, 61 —— ware, 62 Silicic acid, 62 Silver bromide, 48 —— chloride, 48 —— iodide, 48 —— nitrate, 28 —— sand, 61 Soap, hard, 79 ——, soft, 79 Soda, baking, 88 ——, bicarbonate of, 6, 88 ——, bread, 88 ——, caustic, 96 ——, mild, 80 ——, natural, 82 ——, washing, 3, 5, 81 —— water, 49 Sodium, 95 —— nitrate, 29 —— sulphate, 27 Soil bacteria, 38 Solvay process, 90 Sorrel, salts of, 77 Spent oxide, 11 Stalactite, 53 Stalagmite, 53 Stearin, 78 —— candles, 79 Stone ammonia, 99 Suffioni, 60 Sulphur, 11 —— dioxide, 11 —— trioxide, prep. of, 19 Sulphuric acid, properties, 20, 24 —— anhydride, 21 Sulphurous acid, 11 Superphosphate, 57 T Tallow, 79 Tartaric acid, 76 Tinkal, 61 Trinitrotoluene, 35 V Verdigris, 74 Vert de Montpellier, 74 Vinegar, 68 ——, malt, 70 ——, wine, 70 Vitriol, blue, 5 ——, nitrated, 16 ——, oil of, 12 W Ward, Dr., 12 Water, hard, 53 ——, soft, 53 ——, softening of, 54 Wood ashes, source of potash, 3 —— ——, used as soap, 2 Z Zinc chloride, 5 THE END Footnotes [1]An anhydride is a substance which unites with water to form an acid. [2]See Frontispiece. [3]Now £13 a ton. [4]Basic lead carbonate. [5]An electron is probably an “atom” of negative electricity detached from matter.