Page:Radio-activity.djvu/600

  effect of successive precipitations on, 358
  recovery curve after large number of precipitations, 359
  products of, 363
  non-separable activity of, 363
  radiations from active products of, 363
  division of activity amongst active products of, 363
  rate of emission of energy by, 432
  theories of radio-activity of, 438
  discussion of theories of radio-activity, 441 et seq. source of energy of radiations, 442 et seq. theory of radio-active change, 444 et seq. table of radio-active products of, 449 rate of change of, 458 life of, 458 conservation of radio-activity of, 469 total emission of energy from 1 gram of, 475 possible causes of disintegration of, 486 et seq.

Thorium A
  period and properties of, 352 et seq. absence of rays in, 352 effect of temperature on, 354 Thorium B period and properties of, 352 et seq. effect of temperature on, 354 radiations from, 363 Thorium X methods of separation of, 220 law of decay of activity of, 221 law of recovery of activity of, 221 theory to explain production of, 224 material nature of, 226 continuous production of, 227 explanation of decay of activity of, 229 effect of conditions on the rate of change of, 233 disintegration hypothesis to explain production of, 234 minute amount of, produced, 237 effect of successive separations of, on activity of thorium, 358 et seq. analysis of decay and recovery curves of, 358 radiations from, 363 Tommasina scintillations produced by electrification, 160 Townsend ions by collision, 39, 57 coefficient of recombination, 41 diffusion of ions, 51 et seq. comparison of charge on ion with that on hydrogen atom in electrolysis, 53 number of molecules per c.c. of gas, 54 ionization by collision for different speeds, 171 Transformations, successive theory of, 325 et seq. nomenclature of, 328 activity due to, 337 detection of a rayless change in, 341 in uranium, 346 et seq. in thorium, 351 et seq. in actinium, 364 et seq. in radium, 371 et seq. list of, 449 origin of radium in, 459 helium, a result of, 476 et seq. possible cause of, 486 et seq. application of, to evolution of matter, 497 et seq.

Transmission
  of excited radio-activity of radium and thorium, 318 et seq.
  of excited radio-activity of actinium, 323

Travers and Ramsay
  amount of helium in fergusonite, 486

Troost
  rays from hexagonal blende, 4


Uranium
  discovery of radio-activity of, 5
  persistence of radiations of, 6
  discharging power of rays, 7
  absence of reflection, refraction and polarization, 7
  examination of uranium minerals, 11 et seq.
  relative activity of compounds of uranium, 12
  nature of radiations from, 109
  β rays from, 114
  α rays from, 141
  γ rays from, 180
  separation of Ur X from, 219
  recovery of activity of, 219
  changes in, 346 et seq.
  non-separable activity of, 347
  radiations from Ur X, 347 et seq.
  method of measurement of activity of Ur X, 347
  emission of energy by, 418
  theories of radio-activity of, 437 et seq.
  discussion of theories of radio-activity, 441 et seq.