Electromotive Force, defined, iv, 271, 294, 382, vi, 46-9; dangers of uncontrolled, 64-5; generation, 49-66 (see Electric Batteries, Generators, Thermal Couples); induced and generated, vii, 370; measured in volts, iv, 280-1, 284, vi, 53-4, 57; phase relations, 167-9, 171-4, 242; self-induction, vii, 375; uses, vi, 56 (see also Voltage) Electromotive Force Waves, vi, 198-200, 208 Electromotive Series, viii, 127-9, 376 Electrons, vi, 113-15, vii, 367; beta rays, viii, 185, 186; from sun in upper air, i, 144, 146; in charged bodies, 142, 143; in sun, ii, 177-8; knowledge of, from radioactivity, viii, 307; motions in light, heat and electricity, vii, 371; nature, vi, 118, 120; negative electricity, viii, 187-8; original study, xvi, 193; size and weight, i, 141-2, viii, 187; speed in cathode rays, iv, 318 Electron Theory, iv, 321, vi, 26, 122-5, vii, 366, 367, 371, viii, 187-8; compared with Franklin's theory, vi, 288, 292; in various electrical actions, 133-4, 152, 153, 284, 288, 302, 338-9, 340; Larmor's proposal, xvi, 193 Electroplating, vii, 314-19, 374, viii, 164-6, 284 Electro-Refining, vii, 319-21, viii, 166-7, 284 Electrostatic Fields, iv, 261-2, vii, 368; intensity of, 370 Electrostatic Generators, vi, 298-301 Electrostatics, defined, iv, 259; importance of, 271 (see also Charges, Charged Bodies) Electro-Therapeutics, vii, 235-57, 368 Electrotyping, vii, 313-14 Elements, vi, 108-9, viii, 12, 16, 376, 383; atomic numbers, 183, 309; atomic weights (see Atomic Weights); classification, metals and nonmetals, 17-19, 126, 175-7; discoveries through Mendeléeff's tables, 180, 181, 182, xvi, 163; Greek idea of primary, 81, 83; in earth's crust, iii, 308, viii, 19, 190-1, 192, 194; in heavenly bodies, 302; in meteorites, ii, 292; in sea water, xiv, 295; in stars, ii, 115-18; in sun, 114, 128, 185, 211; isotopic and isobaric, viii, 189; made up of molecules, 26; number, 16, 183, 309; only things man cannot produce, vii, 310; origin in silicates, viii, 193; origin, remarks on, 84; periodic classification, 177-83; physical state and chemical properties, 297-8; potentials against hydrogen, vii, 383; properties dependent on atomic weights, xvi, 134; Prout's hypothesis of hydrogen basis, viii, 177; radicals or groups, 93; radioactive, 184-9; spectra of, ii, 113, viii, 302; symbols, 91, 383; tests of, 285-91; transmutation of, 188-9, xvi, 14-15; union types, viii, 20-1, 99-100; valency, vii, 384, viii, 93, 122 Elephants, xii, 301-4; breeding and domestication of, xv, 197; breeding rate, 20; evolution, iii, 300; fearlessness, xi, 136; formerly in Europe, xv, 76, 92; strength of, 18; trapping of, 225, 226 (fig.), 227; trypanosome in, x, 168