Page:Radio-activity.djvu/591

Haschek and Exner
  spectrum of radium, 17

Heat
  rate of emission of, from radium, 419 et seq. emission of, from radium at low temperatures, 420 connection of heat emission with the radio-activity, 421 et seq. source of heat energy, 421 et seq. rate of emission of, after removal of the emanation, 422 et seq. rate of emission of, by emanation, 423, 431 variation with time of heat emission of radium, and of its emanation, 423 heating effect of the emanation, 423, 431 heating effect of active deposit, 425 proportion of heating effect due to radio-active products, 433 origin of, in radium, 442 et seq. total heat emission during life of radio-elements, 474 et seq. heating of earth by radio-active matter, 493 Heaviside apparent mass of moving charged body, 71, 127 Helium produced by radium and its emanation, 476 et seq. amount of, from radium, 480 origin of, 480 Helmholtz and Richarz action of ions on steam jet, 47 Hemptinne action of rays on spark and electrodeless discharge, 208 Henning resistance of radium solutions, 208 effect of voltage on amount of excited activity, 316 Henning and Kohlrausch conductivity of solutions of radium bromide, 208 Hertz electric deviation of cathode rays, 73 Heydweiler loss of weight of radium, 474 Himstedt action of radium rays on selenium, 208 radium emanation in springs of Baden, 513 Himstedt and Meyer production of helium by radium, 479 Himstedt and Nagel action of radium rays on the eye, 217 Hofmann, Gonder, and Wölfl properties of radio-active lead, 27, 413 Hofmann and Strauss radio-active lead, 27 Hofmann and Zerban connection of activity of thorium with uranium, 29 Huggins, Sir W. and Lady spectrum of phosphorescent light of radium bromide, 205 Hydrogen production of, by radium rays, 215 Induced radio-activity (see Excited radio-activity) Induction radio-active, 24 meaning and examples of, 415 et seq.

Insulators
  conduction of, under radium rays, 209

Iodoform
  coloration produced in, by radium rays, 214

Ionization
  theory of, to explain conductivity of gases, 31 et seq.
  by collision, 39, 57
  variation of, with pressure of gas, 61 et seq.
  variation of, with nature of gas, 64
  comparison of, produced by rays, 111, 194
  production of, in insulators, 209
  total, produced by 1 gram of radium, 433 et seq.
  natural ionization of gases, 531 et seq.
  connection of, with phosphorescent and photographic actions, 549

Ions
  in explanation of conductivity of gases, 31 et seq.
  production of, by collision, 39, 57
  rate of recombination of, 40 et seq.
  mobility of, 42 et seq.
  difference between mobility of positive and negative, 43 et seq.
  condensation of water around, 46 et seq.
  difference between positive and negative, 49
  charge carried by, 50
  diffusion of, 51 et seq.
  charge on an ion same as on hydrogen atom, 54
  number of, produced per c.c., 54
  size and nature of, 55 et seq.
  definition of, 56 et seq.