Radium C, therapeutic value of, 254; rays from. 254; generation
of, 254.
Rationality, conditions for development of, 163.
Rays, similarity in nature of gamma, X, and light rays, 248;
effects on living cell, 251; penetration of, 251.
Reade, T. Mellard, finding age of ocean by calcium sulphate, 13.
Recumbent folds, formation of, 155 _et seq._
Regelation, 284; affecting glacier motion, 285.
Reversal, photographic, explanation of, 211.
Richards and Lembert, atomic weight of lead, 27.
Richter, Jean Paul, Dream of the Universe, 200.
Rock salt in the ocean, amount of, 13.