Page:Radio-activity.djvu/592

 velocity acquired by, between collisions, 58 energy required to produce, 58, 551 comparative number of, produced in gases, 65 disturbance of potential gradient by movement of, 65 production of, in insulators, 209 number of, produced by α particle, 433 number produced per c.c. in closed vessels, 533 et seq.

Joly motion of radium in an electric field, 211 absorption of radium rays by atmosphere, 492 (see foot-note)

Kaufmann velocity of cathode rays, 75 variation of e/m with velocity of electron, 127 et seq.

Kelvin theory of radio-activity, 441 age of sun and earth, 492, 493

Kelvin, Smolan and Beattie discharging power of uranium rays, 7

Kleeman and Bragg theory of absorption of α rays, 172 et seq.  relation between ionization and absorption, 174 et seq.   range of α rays in air, 174   four sets of α rays from radium, 174 et seq.

Kohlrausch conductivity of water altered by radium rays, 208

Kohlrausch and Henning conductivity of solutions of radium bromide, 208

Kunz phosphorescence of willemite and kunzite, 203

Kunz and Baskerville phosphorescence of substance under radium rays, 204

Kunzite phosphorescence of, under radium rays, 203

Laborde and Curie heat emission of radium, 419 origin of heat from radium, 440 radium emanation in waters of hot springs, 514

Langevin coefficient of recombination of ions, 41 velocity of ions, 45 et seq. energy required to produce an ion, 58 secondary radiation produced by X rays, 187 slow moving ions in air, 528

Larmor radiation theory, 77 radiation of energy from moving electron, 79 structure of the atom, 157

Lead, radio-active preparation of, 26 radiations from, 26

Le Bon rays from bodies exposed to sunlight, 5 discharging power of quinine sulphate, 9, 530

Lenard ionization of gases by ultra-violet light, 9 action of ions on a steam jet, 47 penetrating power of cathode rays, 73 negative charge carried by Lenard rays, 120 absorption of cathode rays proportional to density, 136, 137

Lerch, von chemical properties of active deposit of thorium, 313 electrolysis of solution of active deposit, 313 effect of temperature on excited activity, 315 temporary activity of active deposit from thorium, 415

Lockyer inorganic evolution, 499

Lodge, Sir Oliver electronic theory, 69 instability of atoms, 487

Lorentz structure of atoms, 157

Lowry and Armstrong radio-activity and phosphorescence, 444

Luminosity of radium compounds, 205 change of, in radium compounds with time, 205 spectrum of phosphorescent light from radium bromide, 206 of radium compounds unaffected by temperature, 210

Mache radium emanation in hot springs, 513

Mache and von Schweidler velocity of ions in air, 528