X RAYS AND RADIUM

Evening Post, Volume CV, Issue 89, 14 April 1923, Page 18

X RAYS AND RADIUM

Among the various obituary notices of the late Professor Rontgen which have been recently published, little attention seems to have been paid to the way in which the discovery of Xray's led to the discovery of radium, says a correspondent in the "Manchester Guardian." It was observed that the X-rays possessed the property of imparting a transient phosphorescence to glass, and this suggested the possibility that substances which could be made phosphorescent by th,e action of ordinary daylight might really bo emitting rays which had the penetrating power and electrical properties of X-rays. For the most part this expectation was disappointed except in the case of certain compounds of uranium, on which Professor Becquerel carried out some ex-' periments. He found that these compounds exceeded his expectations, inasmuch as they produced photographic and electrical effects without having been previously exposed to light. The active agent in them was discovered to be the uranium, which showed its activity in all its compounds. Then it was discovered that the ore residues from which the uranium had been extracted were even more active than the uranium itself, and by working with these residues Mme.. Curie, was able to isolate first polonium (so named in honour of her native country, Poland) and then radium.