ABSTRACT
The half-ounce of radium which has been prepared is gradually wasting away, but it has served already for a series of the most remarkable discoveries that physical science has ever been able to record. When a solution of radium and barium bromides is cooled the radium bromide crystallises out first, and the process has to be repeated over and over again until tests with the electroscope show that the separation is complete. It is on account of the difficulty of this process that radium salts are worth many times more than their weight in gold. The radioactivity of the emanation decays at the same rate as that at which the radioactivity of the original radium is recovered. The study of radioactivity combined with that of electrical discharges in high vacuum, leads to an electrical theory of matter in which the properties of each individual substance are determined merely by the number and arrangement of ultimate particles.
