The interpretation of radium : being the substance of six free popular experimental lectures delivered at the University of Glasgow, 1908 / by Frederick Soddy ; with illustrations.

  • Soddy, Frederick, 1877-1956.
Date:
1909
Catalogue details

Licence: In copyright

Credit: The interpretation of radium : being the substance of six free popular experimental lectures delivered at the University of Glasgow, 1908 / by Frederick Soddy ; with illustrations. Source: Wellcome Collection.

    220/306 (page 178)
    i?8 ATTEMPTS TO DETECT period of life of radium compared with that of uranium X. As already explained (p. 125), chemi- cal and spectroscopic methods of detecting matter depend only on quantity, but radioactive methods depend upon quantity divided by life. Assuming equal effects produced in the disintegration of an atom of uranium X and of an atom of radium, since the life of the latter is 30,000 times that of the former, it will be necessary to have 30,000 times as much radium as of uranium X to produce equal radioactive effects. In 1903 I started a series of special experiments which have been continued ever since I came to Glasgow, partly in conjunction with Mr. T. D. Mackenzie, to see if uranium did not produce radium. The uranium, after being purified as com- pletely as possible by chemical methods from radium, is left sealed up in a flask and periodic- ally tested to see if a growth of radium has occurred. The method of testing for minute traces of radium is a very simple and accurate one, allow- ing quantities of radium of only a few million- millionths part of a grain to be detected with certainty and measured with exactitude. Use is made of the characteristic emanation generated by radium. Uranium does not generate any emana- tion. The uranium solution to be tested for