Methane, viii, 51, 206; combustion products, 61; derivatives, 210, 230-1; flame of, 60; name of, 98 Methodism (medical), x, 26, 28, 29 Methyl, defined, viii, 379 Metric System, iv, 46; adoption in French Revolution, 136; advantage in specific measurements, 111; units in, iv, 69-70, 80-1, 154, viii, 27-8 Meuse River, xiv, 89; delta and shifts, 186 Mexico, ancient civilization (see Aztecs); century plants, xiii, 355; chocolate cultivation, 234; climatic belts, xiv, 223; copper production, iii, 360; corn-growing in ancient, xiii, 212; deserts of, xiv, 380; first hospital, x, 81; harbors and commerce, xiv, 265-6; jaguars of, xii, 362; lava fields, iii, 228; lead production, 362; new volcanoes in, xiv, 320; oil output, iii, 350, 354, v, 173; plateau and hot lands of, xiv, 221, 223; rivers of, 195; rubber plants, xiii, 248; serpents of, xii, 214, 234, 235; silver production, iii, 367-8; vanilla production, xiii, 260; yellow fever in, x, 163 Mexico, Gulf of, importance in rainfall distribution, xiv, 360; sponges in, xii, 32 Meyer, Lothar, xvi, 163; classification of elements, viii, 177 Mica, iii, 334; in granite, 308; chemical composition, viii, 90, 193 Mice, xii, 289-91; snakes and, 220, 227 Michelangelo, anatomical work of, x, 51-2 Michelson, interferometer, ii, 151, 322-3; standard length measurements, xvi, 130 Michigan, copper production, iii, 327, 360, 361; gypsum deposits, 376; iron ores, 357; salt deposits, 375 Michigan, Lake, size, xiv, 204 Micron, wave length unit, iv, 359 Microline, iii, 328 Micrometer, use of, ii, 58, vii, 151 Micronesia, xiv, 277 Microscopes, iv, 343-4; in chemical analysis, viii, 290-1; in medicine, x, 67, 128, 132, xvi, 112-13 Middle Ages, astronomy in, ii, 37-41, 42; comets of, 273; constructive work, 12; ermine fur in, xii, 350; European commerce in, xiv, 240, 241, 307, 308; falconry of, xv, 223; hail and lightning prevention, i, 341; hysteria epidemics in, x, 360; intellectual character of, 34, 35, 43; intellectual lethargy, ii, 11; Jewish polygamy of, xv, 289; magic, xvi, 79; medicine in, x, 31, 34-42, 43; meteoric showers of, ii, 287; minstrels of, xv, 323; painting in, 302-3; poisoning in, 228-9; science in, iv, 27-8; science and philosophy, xvi, 99-105; views of fossils in, iii, 14 Migrations, of birds, xii, 258, xiii, 55; of forests, xiv, 375-6; of plants, xiii, 348 Mikulicz-Rodecki, xvi, 183 Mil, wire measure, iv, 283, 382, vii, 373 Mil Foot, vi, 77 Military Meteorology, i, 306-15