The Becquerel rays and the properties of radium / by R.J. Strutt.

  • Rayleigh, Robert John Strutt, Baron, 1875-1947.
Date:
1906
Catalogue details

Licence: Public Domain Mark

Credit: The Becquerel rays and the properties of radium / by R.J. Strutt. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    that time. The result is to show that radium can melt something like its own weight of ice in an hour. The amount of heat required to do this is not very different from what is required to raise the same quantity of water to the boiling-point, starting at the ordinary temperature. So that we may say, if we prefer, that radium gives off enough heat in an hour to boil its own weight of water. A pound of radium, if we could obtain so much, would be capable of boiling a pint of water in an hour. It would give off as much heat as a small spirit lamp. If we reflect that radium probably retains its powers quite undiminished for hundreds if not thousands of years, it will be admitted that this is one of the most astonishing results in the whole range of science. The quantities of radium available to experiment with are, as we have seen so often, very small; so that they expose, in proportion to the amount of heat liberated, a very large surface. This enables the heat to get away easily. No part of a small mass of radium is very far from the surface. And thus it happens that the temperature does not rise very high. In spite of this, M. Curie has been able to show the heating effect of a fraction of a gramme of radium, by means of an ordinary mercury thermometer, which was heated several degrees hotter than the sur- roundings. If a large mass of radium could be obtained, say a few pounds, the inside would probably be vividly incandescent, with the heat generated. For the out- side layers would serve to hinder the escape of the heat generated by the internal portions. Thus the temperature would be able to rise very high. A most mistaken notion has got abroad that the heating property of radium may have a direct