Detectors, wireless, iv, 315-16, vii, 261, 268-70, 278-80; to guide ships, 284-5 Determiners, inheritance, ix, 329-42, x, 233-4, xiii, 330, xvi, 156 Detonation, of explosives, viii, 262 Detroit, steamers passing, xiv, 212 Devilfish, xii, 78, 148-50 Devil's Tower, Wyoming, iii, 111, 176 (Pl. 10), xiv, 129-30 Devil Whirlwinds, i, 60, 371 Devonian Period, iii, 20, 194-6, 378; "Age of Fishes," 283, xv, 71; animals and plants in, iii, 252, 271, 277, 278, 282-4, 285; extension of sea in, 192 (fig. 37) De Vries, variation studies, xvi, 153 Dew, i, 120-1, 371, xiii, 108; former belief about, i, 119; not formed on cloudy nights, iv, 183 Dewar, liquid air inventions, i, 31, vii, 323 Dewar Flask, viii, 68 Dew Bow, i, 177 Dew Point, i, 78, 79, 371 Dew Ponds, i, 352-3, 371 Dextrin, viii, 227-8; in bread crust, 368; molecules of, 356; production and uses, 241, 243, 244 Dholes, xii, 345 Diabetes, ix, 290, 293-4, x, 276, 330 Diablerets, peaks of, xiv, 202 Diagnosis, art and science of, x, 366-79; Brown's system, 89; chest, 99, 371; Egyptian study of, xvi, 70; of infectious diseases (serum method), x, 215-17; X-rays in, vii, 251, 254, 255, 256, x, 185-6, 372-4 Diamond Drills, v, 263, 264, 380; in ancient Egypt, xvi, 67 Diamonds, iii, 328, viii, 42-3; artificial, vii, 301, 311, xvi, 190; cathode ray effects, 193; cutting of, vii, 300, 309; electrification, vi, 12; in meteorites, ii, 292; X-ray tests, vii, 257 Diana of the Ephesians, ii, 284 Diarrhea, ix, 249, x, 253, 307, 328 Diastole, arterial, x, 62, 63-4, 65; of heart, 65 Diathermanous Bodies, iv, 182 Diatoms, deposits of, iii, 257-8, xiii, 67-8; in tripolite, iii, 335; in sea, xii, 17; oil from, iii, 349; oil storage by, ix, 28 Diatonic Scale, iv, 207 Dichloramin-T., x, 183, 382 Dicotyledons, xiii, 60; antiquity, 207; leaves and flowers, 176, 178; leaves and stems, 177 (fig.); subdivisions, 180, 189-90; various families, 189-205 Dictation, memory after-images in, xi, 220 Dieffenbach, Johann Friedrich, x, 130 Dielectric, of condensers, iv, 264, vi, 302, 305, vii, 366; in lightning, 206; losses due to imperfect, 297-8; strain, 366 Diesel Engines, v, 161-2, 382; efficiency, 164; fuel, 156; in submarines, 199 Diet, bile in relation to, ix, 275; deficiency of, diseases from, x, 255-68, 276; fads of, ix, 285-6; fats and proteins in, 300-1; for reducing weight, 301-2; mixed, man adapted to, 246, 285-6; natural regulation of, 301, x, 255, 257; need of amino acids in, 278; nutrients in daily, viii, 366-7; starch foods in ordinary, ix, 290, 300 (see also Foods, Nutrition) Difform Motion, ii, 80 Diffraction of light, iv, 326, 378; optical phenomena, i, 183-5 Diffraction of sound, iv, 52, 236-7