Report on the separation of ionium and actinium from certain residues and on the production of helium by ionium

The material consisted of certain substances separated from 500 kilos, of pitchblende residues purchased by the Royal Society from the Vienna Academy of Sciences, and treated at the works of the Armet de Lisle at. Nogent-sur-Marne, in France, for the removal of the radium contained in them. The operations to be described were carried out with that portion of the residual material returned to the Royal Society as “actinium residues.” The material consisted of a wet paste, and was a heterogeneous mixture containing considerable proportions of lead chloride and gelatinous silica and small proportions of copper, zinc, iron, tin, and other elements. The preliminary treatment was carried out at the works of Thomas Tyrer and Co., at Stratford, London, under the direction of Mr. H. C. Greenwood, M. Sc., of this laboratory, and consisted of the following operations:- All of the materials separated in the course of these operations were carefully preserved. The various solutions obtained were concentrated by evaporation. The activities of the different products were measured immediately after they had been separated, and were further observed at frequent intervals over a period of about nine months.