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.