INDEX.

Ramsay and Cooke radio-activity produced by radiation from radium, 472
Ramsay and Soddy evolution of gas from radium, 215 production of hydrogen and oxygen from radium, 215 chemical nature of the emanation, 268 gaseous nature of the emanation, 268 volume of emanation, and change with time, 289 helium from radium emanation, 291 amount of helium produced by radium, 480
Ramsay and Travers amount of helium in fergusonite, 486
Rayless changes discussion of, 454, 552
Re, F. theory of radio-activity, 441
Recombination of ions, 40 et seq. constant of, 42
Recovery of activity of thorium after removal of Th X, 221 of activity of uranium after removal of Ur X, 223 significance of law of, 224 effect of conditions on rate of, 232 of activity of radium after removal of emanation, 372 of heating effect of radium, 423
Reflection no evidence of direct reflection for uranium rays, 7 diffuse reflection of rays, 7
Refraction no evidence of, for uranium rays, 7
Regeneration of emanating power, 256
Richarz and von Helmholtz action of ions on steam jet, 47
Richarz and Schenck theory of radio-activity, 441
Rossignol and Gimingham decay of thorium emanation, 242
Runge spectrum of radium, 17
Runge and Bödlander evolution of gas from radium, 215
Runge and Precht spectrum of radium, 17 atomic weight of radium, 18 heating effect of radium, 420
Russel photographic action of substances, 83
Saake amount of emanation in air at high altitudes, 519
Salomonsen and Dreyer coloration of quartz by radium rays, 213
Saturation current meaning of, 33 et seq. application of, to measurements of radio-activity, 84 measurement of, 100 et seq.

556