ABSTRACT
Author gives an account of some experiments which he had made upon the growth of radium in preparations of actinium. Another sample of actinium was then taken and successively precipitated with ammonium sulphide in order to remove the radium from the solution. This actinium precipitate was dissolved in hydrochloric acid, and observations of the amount of radium in it were made at regular intervals. No appreciable growth of radium was observed over a period of eighty days. This immediate parent of radium is chemically quite distinct from actinium and radium and their known products, and is capable of complete separation from them. It is not improbable that it may prove to be the long-looked-for intermediate product of slow transformation between uranium X and radium, but with no direct radio-active connection with actinium. Experiments are also in progress to isolate this new substance in order to examine its chemical and radio-active properties.
