INDEX 417 lv, lvii n, 3n, 281n, 380 Elasticity, coefficient of, for gases, 101 Elastic medium, 7-9 "Electra" Apparatenbau-Ges. m.b.H., Vienna, liv n Electrical charge (elektrische Masse), 224, 226 surface density of, 160-161 Electrical circuits: closed, 177, 178, 181 Kirchhoff's laws for, 181-184 networks, 182 parallel, 184, 192 series, 192 three- wire system, 185 Electrical conductivity: of negative charge car- riers, Drude on, 284, 285n relation to ther- mal conductivity, 194, 305n H. F. Weber on, 235 Electrical conductor (elektrischer Leiter): distri- bution of electrical charge on, 159-161 rela- tionship between charge and potential of, 161-167 Electrical force (elektrische Kraft), AE on defi- nition of, 226 Electrical phenomena, 235-237 Electrical potential, 161-164 Electrical resistance (elektrischer Widerstand), 175-210 in branched conductors, 184-187 measurement of, 35, 186-190 specific, of copper, 199-200 specific, dependence on temperature, 190-191 specific, of metals, 190-191 units of, 191-194 Electrical resonator energy (elektrische Resona- torenenergie), as source of internal kinetic energy, AE on, 235-236, 279 Electric current (elektrischer Strom), 6, 7, 9, 172, 227n as motion of charges in empty space, AE on, 224, 226 distribution in Vol- taic cell, 176-178 measurement of, 35, 158, 200-210 units of, 207 Electric field, 5, 223-225 Electricity, xxxix, xl, 5-6, 148-210, 224, 227, 236, 238 Electric lighting filaments, 197n Electric meters, lii n Electric motors, liv n Electric polarization: in Hertz's electrodynam- ics, 223, 226 of molecules, 172 Electrochemical equivalent (elektrochemisches Äquivalent), 226 Electrochemistry, 286 Electrodynamics of moving bodies (Elektrody- namik bewegter Körper), xl, 223-225, 226- 227, 325, 328, 330 Electrolysis, 226n Electromagnetic force (elektromagnetische Kraft), 205 Electromagnetic waves (elektromagnetische Wellen), xxxix, 5, 6, 6-9, See also Light Ra- diation Ether waves Electromagnetism, AE's study of and com- ments on, xxxix, xl, 6, 223 Electrometer, 172 quadrant, 156-158, 162- 164 Electromotive force (elektromotorische Kraft), 35, 178, 181, 201 Electron theory of metals (Elektronentheorie der Metalle), AE's interest in, xl, 236-237, 238, 284-285, 287, 303, 304n, 305, 306, 309n. See also Drude, Paul Reinganum, Maximilian Riecke, Eduard Electrons (Elektronen negative elektrische Kerne), 236-237, 284-285 Electrostatic force, 150-156 Electrostatic induction, 164-167 Electrotechnology, 307, 308n, 327 Elektrische Masse. See Electrical charge Elektrischer Strom. See Electric current Elektrizität. See Electricity Elektrochemie. See Electrochemistry Elektrochemisches Äquivalent. See Electro- chemical equivalent Elektrodynamik bewegter Körper. See Electro- dynamics of moving bodies Elektromagnetische Wellen. See Electromag- netic waves Elektromotorische Kraft. See Electromotive force Elektronen. See Electrons Elektronentheorie der Metalle. See Electron theory of metals Elektrotechnik. See Electrotechnology Elementary magnets (Magnetismen), 227 Elliptical functions (elliptische Funktionen), 212n Emmert, Karl (1813-1903), 335n Energy, conservation of, 7, 92-94 Engel, Franz Joseph, 348, 350 Engelbrecht, Johanna (1855-1940), 255n, 283n, 285n, 288, 293, 301 Entropy, definition of, 114n Equipartition theorem, 305n Erdmagnetische Kraft. See Magnetic field, ter- restrial Ether (Aether), 223-224, 226, 285, 330 AE's early interest in, xxxix, xl, 5-6, 6-9 AE's experiments to detect motion relative to, 224-225, 230, 233, 234n, 316, 328, 329n Ether forces (Aetherkräfte), 7-9 Ether waves (Aetherwellen), 7-8 ETH (Eidgenössische Polytechnische Schule) AE's 1895 attempt to enter, xxxvi, lxiv, lxv,