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.

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    itself at least three changes follow one another with great rapidity, so that the analysis of them proved a complicated task. You know that if a moisture-laden atmosphere is sufficiently chilled, the vapour of water condenses directly into the solid form, and a snowstorm results. Something of this kind is always happen- ing in an atmosphere containing the radium emanation. Every second two out of every million of the atoms of emanation disintegrate, expelling a-particles and leaving a solid residue, so that there is a sort of continuous snowstorm silently going on covering every available surface with this invisible, unweighable, but intensely radioactive deposit. Unlike snow, however, the particles of this active deposit are charged with positive electricity, so that if two surfaces are provided, one charged nega- tively and the other positively, the deposit is attracted almost entirely to the negatively charged surface. The other surface repels the particles and so does not get coated. By making the negatively charged surface very small the active deposit can be almost entirely concentrated upon it. This enables me to show you more effectively the pro- duction of the active deposit from the emanation and some of its chief properties. It would, however, take us too long and too far