Marble, description and uses of, 100 ——, statuary, 102—105—109 ——, Pentelic, Greek white, and Parian, 101 ——, Carrara, Luni, and Verde antique, 102 ——, Sienna, Brocatello, Mandelato, Verde di Prato, Lago Maggiore, Bretonico, and Campan, 103 ——, Griotte, Marquese, Sarencolin, St. Beaume or Languedoc, Breccia of the Pyrenees, 104 ——, white Spanish, Seville, Tortosa, Grenada, Spanish Breccia, 105 ——, Lumachelli, Sicilian, Swiss, Portuguese, Russian, Asiatic marble of Tabriz, African, American, 106 ——, Petworth, Purbeck, 107 ——, Babbicombe, Derbyshire, Kendal, Mona, Tirie, 108 ——, Assynt, Isle of Sky, Sutherland, Glen Tilt, 109 ——, Blairgowrie, Glenavon, Ballichulish, Blairmachyldach, 110 ——, mode of cutting and polishing, 111 ——, black, 111 ——, Florence, 115 ——, Cottam, 116 Marcasite. See Pyrites. Marking ink, for linen, &c. how made and used, 181 Marl, description and uses of, 114 Matrix, 4 Meerschaum, how obtained, prepared, and used, 84 Mercury, the ores of, 173 ——, how extracted from the ore, 175 ——, properties and uses of, 175, 176 Mercury mines in India, description of, 175 Metals, different states in which they are found, 165 ——, how obtained and prepared for use, 165 Meteoric stones, description of, 193 —— ——, extraordinary instances of their falling from the air in 1492, 1672, 1704, 1795, 1814, &c., 195 —— ——, opinions of learned men respecting, 197 —— ——, properties of, 194 Mica, description of, how obtained, and uses of, 81 Mica slate, or micaceous schistus, 227 Millstones. See Burr Stone. ——, Peak, what formed of, 233 ——, of granite, 225 Millstone grit, description and uses of, 233 Mineral green, of what made, 141 Mineral oil. See Petroleum. Minerals, systematic arrangement of, 4 Mineral tar, description and uses of, 148, 149 Minium, how manufactured, and uses of, 206 Mochoa stone, description and use of, 63 —— ——, imitations of, how made, 63 Mona marble. See Serpentine. Moonstone, description and use of, 70 Mountains, comparative heights of the principal, 237 Muriatic acid, 13 Muriats, 13 Muscovy glass. See Mica. Music plates, of what made, 217 N. Naphtha, where found, uses and properties of, 146 Natron, description of, how obtained and uses of, 128 Nephrite. See Jade. Nickel, description and uses of, 208 ——, oxide of, and for what used, 209 Nitrats, 14 Nitrat of silver, uses of, 181 Nitre, description of, how and whence obtained, 136 ——, how manufactured, and uses of, 136, 137 Nitric acid. See Aqua fortis. Nova Mina topaz, 37 O. Ochre, red, description and uses of, 199 Obsidian, description and uses of, 66 Oil, rancidity of, how corrected, 207 Onyx, description and use of, 57 Opal, description of, where found, use and value of, 63 ——, imitations of, 64 ——, Hydrophanous, singular quality, use, and value of, 64 ——, Common, 65 ——, Mother of pearl, and wood opal, 65, 66