Hevesy , George Charles von

(1885–1966) Hungarian–Swedish chemist

Hevesy came from a family of wealthy industrialists in Budapest, the Hungarian capital. He was educated in Budapest and at the University of Freiburg where he obtained his doctorate in 1908. He then worked in Zurich, Karlsruhe, Manchester, and Copenhagen, before his appointment to the chair of physical chemistry in 1926 at Freiburg. In 1935 he left Germany for Denmark, fleeing from the Nazis who caught up with him once more in 1942, when he sought refuge in Sweden at the University of Stockholm.

In 1923 Hevesy discovered the new element hafnium in collaboration with Dirk Coster. His most important work, however, began in 1911 in the Manchester laboratory of Ernest Rutherford, where he worked on the separation of ‘radium D’ from a sample of lead. In fact radium D was a radioactive isotope of lead (lead–210) and could not be separated by chemical means. Hevesy was quick to see the significance of this and began exploring the use of radioactive isotopes as tracers. In 1913, with Friedrich Adolph Paneth, he used radioactive salts of lead and bismuth to determine their solubilities. In 1923 Hevesy made the first application of a radioactive tracer – Pb–212 – to a biological system. The Pb–212 was used to label a lead salt that plants took up in solution. At various time intervals plants were burned and the amount of lead taken up could be determined by simple measurements of the amount of radioactivity present. The drawback of this technique was the high toxicity of lead to most biological systems and it was only with the discovery of artificial radioactivity by Irène and Frédéric Joliot-Curie in 1934 that Hevesy's radioactive tracers developed into one of the most widely used and powerful techniques for the investigation of living and of complex systems. For his work in the development of radioactive tracers Hevesy was awarded the 1943 Nobel Prize for chemistry.