ABSTRACT
The British radium standard does not differ much in radium content from the international standard, containing about 20 milligrams of pure radium chloride. It will be remembered that Dr. Beilby, F. R. S., very generously defrayed to Mme. Curie the cost of the radium forming the international standard. Immediately after the fixing of the international standard, arrangements were made in this country to obtain a duplicate standard to be placed in charge of the National Physical Laboratory at Teddington. A circular has now been issued by the National Physical Laboratory, stating that they are prepared to standardise preparations of radium and mesothorium in terms of the international standard. Tests on radio-active minerals, radio-active waters and other materials of weak activity, arrangements will be made as the new radio-active department progresses to undertake some work of this character in the future. Both the Reichsanstalt and the National Physical Laboratory express the activity of their preparations in terms of metallic radium.
