ABSTRACT
IN a recent number of the Philosophical Magazine, Lord Rutherford have shown that radium, after passing through four rapid changes, finally gives rise to two slow transformation products, which, on the scheme of changes there outlined, were called radium D and radium E. These two products can be separated from each other by suitable physical and chemical methods. Evidence was also shown that radium D was the active constituent in the radio-active lead of Hofmann, and that radium E was the active substance present in both the polonium of Mme. Radium D, which is the parent of E, gives out only j8 rays, while E gives out only a rays. Polonium, radio-tellurium, and radium E have very similar radio-active and chemical properties. This chapter examines the rates of decay of the activity of radium E and of radio-tellurium, and has found them to be identical.
