Nobel Prize for Chemistry for 1944: Prof. Otto Hahn

Abstract

PROF. OTTO HAHN, to whom the Nobel Prize for Chemistry for 1944 has been awarded, in recognition of his discovery (with F. Strassmann) of the neutron-induced fission of uranium and thorium (in its chemical aspects), has for long been universally recognized as the outstanding 'radioactive' chemist of his generation. Born sixty-six years ago, he began his studies in radioactivity in his early twenties under Sir William Ramsay at University College, London, proceeding from there, as Soddy had done previously, to work for a time with Rutherford in Montreal. In London he discovered radiothorium, an intermediate product between thorium and thorium X, and in Montreal radioactinium—and also carried out purely physical experiments on the magnetic and electric deflexions, and on the ranges, of the α-particles from thorium C. Having returned to Berlin (1906), he isolated mesothorium 1 (1907) and mesothorium 2 (1908), and from that date he continued to contribute regularly to—and in general to lead—the great advances in specialized chemical technique required for pioneering work with the heavy radioactive elements. His thirty years association with Lise Meitner (1908–38) provides a classical example of the happy collaboration of chemist and physicist to the mutual advantage of both sciences. It was terminated only by the rigour of the laws of racial discrimination which were enforced in Hitler's Germany. No doubt it is more than a slight consolation in the face of imposed separation that Meitner and Hahn should each have been able to contribute, one on the physical, the other on the chemical side, to the original elucidation of the problem of uranium fission. During the War, Hahn continued to work on the chemical side of this problem and many of the results which he and his colleagues obtained were permitted full publication by the German censor.