INDEX.

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. analysis of α ray curves, 377 α ray curves of, 378 β ray curves of, 379 analysis of β ray curves, 381 equations of activity curves, 389 effect of temperature on, 390 volatility of, 391 of slow transformation, 311, 397 variation of α ray activity of, 398 variation of β ray activity of, 399 separation of constituents of, 401 et seq. successive products in, 402 variation of activity of, for long periods, 407 presence in old radium, 408 effect of, on variation of activity of radium with time, 409 presence in pitchblende, 410 connection with radio-tellurium, 411 connection with polonium, 411, 412 connection with radio-lead, 413 connection of, with radio-active induction, 415 et seq. heat emission of, 425 et seq. use of, to determine number of β particles from radium, 435 use of, as source of α rays, 543
Des Coudres magnetic and electric deviation of α rays, 148 determination of e/m for α rays, 148
Dewar emission of heat from radium in liquid hydrogen, 420
Dewar and Crookes absence of nitrogen spectrum in phosphorescent light of radium at low pressures, 206
Dewar and Curie production of helium by radium, 479
Dielectrics condition of, under radium rays, 209
Diffusion of ions, 51 et seq. of radium emanation into gases, 270 of thorium emanation into gases, 275 of radium emanation into liquids, 276
Discharge action of rays on spark and electrodeless, 208

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