Radio-activity / by E. Rutherford.

  • Ernest Rutherford
Date:
1904
Catalogue details

Licence: Public Domain Mark

Credit: Radio-activity / by E. Rutherford. Source: Wellcome Collection.

    19/426 page 3
    simpler forms the atoms of the elements by the action of the chemical or physical forces at our command. On this theory we are witnessing in the radio-active bodies a veritable transformation of matter. This process of disintegration was investigated, not by direct chemical methods, but by means of the property possessed by the radio-active bodies of giving out specific types of radiation. Except in the case of a very active element like radium, the process of disintegration takes place so slowly, that hundreds if not thousands of years would be required before the amount transformed would come within the range of detection of the balance or the spectroscope. In radium, however, the process of disintegration takes place at such a rate that it should be possible within a limited space of time to obtain definite chemical evidence on this question. The recent discovery that helium can be obtained from radium adds strong confirmation to the theory; for helium was indicated as a probable disintegration product of the radio-active elements before this experimental evidence was forthcoming. If the production of helium by radium is completely substantiated, the further study of radio-active bodies promises to open up new and important fields of chemical enquiry. In this book the experimental facts of radio-activity and the connection between them are interpreted on the disintegration theory. Many of the phenomena observed can be investigated in a quantitative manner, and prominence has been given to work of this character, for the agreement of any theory with the facts, which it attempts to explain, must ultimately depend upon the results of accurate measurement. The value of any working theory depends upon the number of experimental facts it serves to correlate, and upon its power of suggesting new lines of work. In these respects the disintegration theory, whether or not it may ultimately be proved to be correct, has already been justified by its results. 2. Radio-active Substances. The term “ radio-active ” is now generally applied to a class of substances, such as uranium, thorium, radium, and their compounds, which possess the property of spontaneously emitting radiations capable of passing through plates of metal and other substances opaque to ordinary light. 1—2
    digitised image 1
    digitised image 2
    digitised image 3