Page:Radio-activity.djvu/585

 comparison of, when exposed to γ rays and to hard X rays, 184 of insulators, 209 of air in caves and cellars, 507 et seq.  of air in closed vessels, 531 et seq.   variation of, in closed vessels with pressure and nature of gas, 534   variation of, with temperature for air in closed vessels, 536   increase of, with time, in a closed vessel, 537  Conservation of radio-activity   examples of, 469 et seq.

Cooke, H. L. penetrating rays from the earth, 520 number of ions per c.c. in closed vessels, 534 radio-activity from ordinary matter, 536

Cooke, W. T. and Ramsay radio-activity produced by radiations of radium, 472

Corpuscle (see Electron) Crookes, Sir W.   spectrum of radium, 17   spectrum of polonium, 23   nature of cathode rays, 73   nature of α rays, 142   scintillations produced by radium, 158   spinthariscope, 158   number of scintillations independent of pressure and temperature, 159   phosphorescence of diamond, 204   separation of Ur X, 219   theory of radio-activity, 441  Crookes and Dewar   absence of nitrogen spectrum in phosphorescent light of radium at low pressures, 206  Crystallization   effect of, on activity of uranium, 349  Curie, Mme   permanence of uranium rays, 6   discovery of radio-activity of thorium, 10   radio-activity of uranium and thorium minerals, 11   relative activity of compounds of uranium, 12   coloration of radium crystals, 15   spectrum of radium, 16   discovery of polonium, 22   nature of a rays, 142   absorption of α rays from polonium, 163   secondary radiation tested by electric method, 188   slowly decaying excited activity from radium, 311   recovery of activity of radium, 375   bismuth made active by solution of barium, 417  Curie, P.   magnetic deviation of radium rays by electric method, 114   conductivity of dielectrics under radium rays, 209   radio-activity of radium unaffected by temperature, 210   decay of activity of radium emanation, 247   discovery of excited radio-activity from radium, 295   heat emission of radium at low temperature and variation of heat emission with age of radium, 419   nature of the emanation, 439  Curie, M. et Mme   discovery of radium, 13   charge carried by β rays, 121   luminosity of radium compounds, 205   production of ozone by radium rays, 213   coloration of glass by radium rays, 213   theory of radio-activity, 439   possible absorption by radio-elements of unknown radiations, 442  Curie, J. et P.   quartz piezo-électrique, 105 et seq.

Curie, P. et Danne 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

Curie, P. and Debierne 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

Curie and Dewar production of helium by radium, 479

Curie, P. and Laborde heat emission of radium, 419