UNSTABLE NITROGEN

Evening Post, Volume CXVII, Issue 63, 15 March 1934, Page 13

UNSTABLE NITROGEN

"ARTIFICIAL RADIUM"

A NEW DISCOVERY

(From "The Post's" Representative.) LONDON, February 2. After some twenty years' research success has attended the efforts of scientists to produce artificial radioactivity. The son-in-law of Mine. Curie, who first isolated radium, has produced the nearest approach to artificial radium that the world has yet seen. AVhat lie has done (says the "Morning Post") is to transmute the element boron (of boracic acid), by bombarding its atoms, into a form of nitrogen which is unstable and breaks down of its own accord. It probably changes into carbon, just as radium in. the course of. millions of years is slowly turning', through a number of intermediate products, into lead. But whereas the life of radium is measured in thousands of years, the life of M. Joliot's unstable nitrogen is only about fifteen minutes. This is the time needed for the initial radioactivity to fall by 70 per cent. It compares with the six days' life of "radon," a gas which may' be collected from radium and which is used medically as "radon seeds." As regards penetrating power, it is estimated that M. Joliot's radiation would reach perhaps an inch into the human "body. His discovery immediately raises the question whether it would not be possible to produce artificial radio-activity as penetrating and as long-lived as that of radium. There appears to be no theoretical reason" why this should be impossible. At the same time, the "lives" of the only two other kinds of unstable atom yet produced by M. Joliot are both shorter than that of unstable nitrogen, and his "output" has been infinitesimally small. LORD RUTHERFORD'S VIEWS. M. Joliot's radiation differs from that of radium in that it consists solely of the recently discovered "positive" electrons. It is for this reason that this form of radio-activity has not been discovered before. Scientists.had always looked for the very much heavier particles which are an essential part of radium radiation. The part of radium radiation which is regarded as medically useful is, however, different again, and for this reason the medical possibilities" of the radiation now discovered would have to be explored afresh. "It is an interesting and probably important discovery," Lord Rutherford said in an interview. "The remarkable thing is that the life of the unstable atom produced is as long as it is. But we cannot tell whether it is typical,-or longer or shorter than the life of other unstable atoms which may perhaps be produced. M. Joliot's discovery shows how little wo really know about radio-activity."