A brief history of Lord Rutherford's radiumby N. Todd

Notes and Records: the Royal Society journal of the history of science


History and Philosophy of Science


radioa his

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Soddy between 1900 and 1902.4 Together they worked out the theory of successive tra e wi ly *neil.todd@manchester.ac.uk

Notes Rec. (2014) 68, 279–300 doi:10.1098/rsnr.2013.0070

Published online 21 May 2014 on December 10, 2014http://rsnr.royalsocietypublishing.org/Downloaded from nsformations to explain the nature of radioactivity, but most of this work was don th thorium. His earliest work using radium was performed with preparations, variousDURING RUTHERFORD’S LIFE

Montreal, 1898–1907 ring the period when radium was discovered, isolated and made commercially availabl therford worked at McGill University in Montreal as Macdonald Professor of Physic uch of his important work there was done in collaboration with the chemist Fredericlaboratories in Manchester, and which was recently the subject of a review. Although a preliminary account of this has been provided as part of the review,2 given Rutherford’s unique and central role in the development of modern physics there is a particular interest in tracing specifically the history of the radium in his possession that was accumulated during his career. This account follows on from a recently published description of the role of the Royal Society in these affairs.3s. The background to the present work is an interest in the origin and fa ctive substances in the possession of Rutherford that led to contamination inIn this paper I give a brief summary of what is known about the acquisition, use and fate of the radium sources that were in the possession of Lord Rutherford during his lifetime. The account is written in two parts, corresponding to the periods from the discovery of radium in 1898 until his death in 1937 and then from 1937 until recent times. The history of

Rutherford’s radium closely shadows the history of radioactivity, the evolution of nuclear physics, the race for the bomb, and the development of the nuclear industry.

Keywords: radium; Rutherford; radioactivity

Radium stands out among the naturally occurring isotopes for its radioactive potency, the degree to which it captured the public imagination after its discovery, and its unique role in the development of science and medicine. For these reasons the broad history of radium is of considerable interest, and several previous works have given an account of thi 1 te ofA BRIEF HISTORY OF LORD RUTHERFORD’S RADIUM by


Faculty of Life Science, University of Manchester, Manchester M13 9PL, UK279 q 2014 The Author(s) Published by the Royal Society. 5Germ oddy move ) on the p nced upon was

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N. Todd280 on December 10, 2014http://rsnr.royalsocietypublishing.org/Downloaded from Soddy wrote to Rutherford on 13 July as follows:9

If you received my wire you will have heard the results of the second experiment with your radium. . . . It is a veritable triumph and we are very grateful to you for making it possible. Your radium weighed 31.8 mg and I hope soon to hear from the manufacturers when I shall get my 30 mg from them.

It is apparent from the subsequent letters between Soddy and Rutherford during autumn 1903 that Isenthal’s reputation had been damaged by the selling of poor-quality preparationsastonishment and joy that I had experienced when confronted with radium bromide for eight shillings a milligram some weeks before. He was absolutely bowled over and became as excited as a school boy over the coming holidays. With thirty precious milligrams of pure radium bromide we bounded back to Gower Street and we both immediately repaired to the dark room with some metal foils and a bit of X-ray screen.

The effect was terrific; it was like a person born blind suddenly being given sight, for though R had made a special study of the Becquerel rays, this was the first time he had ever seen them. All his work had been done by the ionization method with substances far too feebly radioactive to light up the X-ray screen. Now he had a visual demonstration of what he had found out in the dark—so to speak.8 fore his return to Montreal, Rutherford lent his 30 mg of radium to Soddy and Ram ontribution to the helium experiments, the apparatus for which is shown in figuvisited Soddy in London.

I told him immediately on his arrival at UCL about my find at Isenthal’s and together we lost no time in walking round to Mortimer St. I must say he experienced the sameprospect was changed. . . . I was walking along Mortimer St off Upper Regent Street, in London one day when, casually looking through Isenthal’s window, I saw advertised something I could not credit to be true: ‘pure radium compounds on sale here’. . . . I learnt from the salesman that Professor Giesel in Germany . . . had started manufacture of radium compounds on a commercial scale in the Chinin Fabrik at Brunswick. He used residues left after the extraction of uranium from the Pitchblende found in the old state silver mine of St Joachimsthal in Bohemia. Isenthal had quickly taken advantage of this supply. At that time one could buy radium only from the French factory by favour of the Curies. Here it was to be bought in a London shop at some eight shillings a milligram of pure radium bromide.6 ddy purchased 20 mg of radium bromide, which was delivered to Ramsay’s labor ime in early July.7 Sometime shortly after this, in the summer of 1903, Rutheadvertising Giesel’s radium:

Our trouble here was the same as in Montreal. We had a quite insufficient amount of radium for our investigations. Then, by the most extraordinary chance, the whole futurean chemist Friedrich Giesel became readily available. In the spring of 1903 S d to London to work with William Ramsay at University College London (UCL roduction of helium from radium. Shortly after arriving in London, Soddy cha

Isenthal’s shop on Mortimer Street, about 20 minutes walk from UCL, whichobtained from Julius Elster and Hans Geitel in Germany and the Curies in Paris, that were in the form of the barium radium chloride salt. These sources were, however, rather weak and limited in supply.