Page:Radio-activity.djvu/586

  origin of heat from radium, 440
  radium emanation in waters of hot springs, 514

Current
  through gases, 31 et seq. variation of, with distance between the plates, 59 et seq. variation of, with pressure of gas, 61 et seq. variation of, with nature of gas, 64 measurement of, by galvanometer, 84 measurement of, by electroscope, 85 et seq. measurement of, by electrometer, 90 et seq. measurement of, by quartz piezo-*électrique, 105 Dadourian presence of thorium emanation in the earth, 512 Danne on deposit of radium not containing uranium, 465 Danne et Curie diffusion of radio-active emanation, 272 decay of excited activity from radium, 309 decay curves of radium and equation, 309 occlusion of radium emanation in solids, 310 changes in radium, 381 effect of temperature on active deposit, 390 Danysz action of radium rays on skin, 216 Darwin, G. H. age of sun, 492 Debierne actinium, 21 emanation from actinium, 249 decay of excited activity from actinium, 311 effect of magnetic field on activity excited from actinium, 324 barium made active by actinium, 417 Debierne and Curie evolution of gas from radium, 215 active gases evolved from radium, 251 phosphorescence produced by radium emanation, 252 distribution of luminosity, 252 rate of production of emanation independent of pressure, 266 effect of pressure on amount of excited activity, 266, 317 Decay of activity of Th X, 221 of activity of Ur X, 223 significance of law of, 229 effect of conditions on the rate of, 232 of activity of thorium emanation, 241 of activity of radium emanation, 247 of activity of actinium emanation, 249 of excited activity due to thorium for long exposure, 302 of excited activity due to thorium for short exposure, 304 of excited activity due to radium, 306 et seq. excited activity of slow decay due to radium, 311 of excited activity from actinium, 311 of radium A, B and C, 377 et seq. of radium D, E and F, 397 et seq. of heating effect of emanation, 423 of excited activity from atmosphere, 502 of activity of rain and snow, 506 of emanation from the earth, 508 differences in, of excited activity from atmosphere, 521 et seq.

Demarçay
  spectrum of radium, 16

Deposit, active
  connection of, with excited activity, 301
  physical and chemical properties of, 312
  electrolysis of, 313
  effect of temperature on, 315
  effect of pressure on distribution of, 317
  transmission of, by positive carriers, 318 et seq.
  nomenclature of, 328
  theory of changes in, 331 et seq.
  theory of activity due to, 337 et seq.
  theory of rayless change in, 341 et seq.
  of thorium, 302 et seq., 351 et seq.
    analysis of, 351
    rayless change in, 352
    effect of temperature on, 354
    period of products of, 355
  of actinium, 311 et seq.
    decay curves of, 311
    analysis of, 367
    rayless change in, 367
    period of products of, 368
    radiations from, 368
  of radium, 376 et seq.
    connection of excited activity with, 306
    general analysis of, 376 et seq.
    analysis of, of rapid change, 377 et seq.