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.