The Production of Radium from Uranium

Abstract

EXPERIMENTS on which I have been engaged for the past six years have until now failed to establish the production of radium from uranium. With carefully purified uranium salts, using considerable quantities, the growth is too small to be detected for the first two or three years, and is less than 1/10,000 of what would occur if a direct change of uranium into radium took place. With commercial uranyl nitrate, on the other hand, purified from radium by precipitating barium sulphate in the solution, a distinct though small production of radium was observed in 1905, and subsequently confirmed (Phil. Mag., October, 1908, 632). This is explained by the existence of an intermediate parent of radium in the series with a very long period of life, which has been found by Boltwood and by Rutherford in preparations of actinium, and recently isolated by the former from uranium minerals, and called “ionium.”