[122] _Journal of the Chemical Society_, vol. xci. (1907), pp. 1605-1606. More recent experiments, however, proved that the α-particle does consist of an electrically charged helium-atom, and this view was latterly accepted by Sir William Ramsay, so that the above suggestions must be modified in accordance therewith. (See § 94.) Further Experiments on Radium and Copper. § =99.= A little later Madame Curie and Mademoiselle Gleditsch[123] repeated Cameron and Ramsay’s experiments on copper salts, using, however, platinum apparatus. They failed to detect lithium after the action of the emanation, and think that Cameron and Ramsay’s results may be due to the glass vessels employed. Dr. Perman[124] has investigated the direct action of the emanation on copper and gold, and has failed to detect any trace of lithium. The transmutation of copper into lithium, therefore, must be regarded as unproved, but further research is necessary before any conclusive statements can be made on the subject. [123] Madame CURIE and Mademoiselle GLEDITSCH: “Action de l’émanation du radium sur les solutions des sels de cuivre,” _Comptes Rendus hebdomadaires des Séances de l’Académie des Sciences_, vol. cxlvii. (1908), pp. 345 _et seq._ (For an English translation of this paper, see _The Chemical News_, vol. xcviii. pp. 157 and 158.) [124] EDGAR PHILIP PERMAN: “The Direct Action of Radium on Copper and Gold,” _Proceedings of the Chemical Society_, vol. xxiv. (1908), p. 214. Ramsay’s Experiments on Thorium and allied Metals.