![]() ![]() These results of his examination are set forth in a special note following ours. Demarçay has examined the spectrum of our material so obligingly that we cannot thank him enough. These facts may be understood in terms of the presence of a radioactive element whose chloride is less soluble in a water solution of alcohol than that of barium.ģ. ![]() We have been stopped by the lack of material but, from the progress of the work, it is anticipated that the activity would have increased much more if we had been able to continue. Based on this fact, one ought to be able to effect a series of fractionations, securing an activity nine hundred times greater than that of uranium. In dissolving these chlorides in water and in precipitating a part with alcohol, the part precipitated is much more active than the part remaining in solution. The first preparations which have been obtained, in the form of the hydrated chloride, have a radioactivity sixty times stronger than that of metallic uranium (the radioactive intensity being evaluated by the conductivity of the air in our plate apparatus). ![]() From this point of view, if the radioactivity of our substance is not due to barium, it must be attributed to another element.Ģ. Barium and its compounds are not ordinarily radioactive but one of us has shown that radioactivity appears to be an atomic property, persisting in all the chemical and physical states of the material. The following are the reasons which argue in favour of this view:ġ. We believe nevertheless that this substance, although constituted for the greater part by barium, contains in addition a new element which gives it its radioactivity and which moreover is very close to barium in its chemical properties. ![]() Finally this substance shows the easily recognized spectrum of barium. The new radioactive substance that we have just found has all the chemical aspects of nearly pure barium: It is precipitated neither by hydrogen sulphide, nor ammonium sulphide, nor by ammonia the sulphate is insoluble in acids and water the carbonate is insoluble in water the chloride, very soluble in water, is insoluble in concentrated hydrochloric acid and in alcohol. In fact, polonium is precipitated out of acid solutions by hydrogen sulphide, its salts are soluble in acids, and water precipitates them from these solutions polonium is completely precipitated by ammonia. The investigations which we are now following are in accord with the first results obtained, but in the course of these researches we have found a second substance strongly radioactive and entirely different in its chemical properties from the first. We have stated the opinion that pitchblende may possibly contain a new element for which we have proposed the name polonium. This substance is closely related to bismuth in its analytical properties. Two of us have shown that by purely chemical processes one can extract from pitchblende a strongly radioactive substance. Boorse and Lloyd Motz, eds., The World of the Atom, vol. BecquerelĬomptes Rendus 127, 1215-7 (1898) translated and reprinted in Henry A. Bémont On a new, strongly radioactive substance, contained in pitchblende Curies Radium Pierre Curie (1859-1906), Marie Sklodowska Curie (1867-1934), and G. ![]()
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