THE enormous literature which has developed from the discovery of radium and from the study of cognate phenomena has made it increasingly difficult to form a calm opinion upon the merits of all the claims which have been advanced, and upon the validity of the theories which have been based upon them. Undoubtedly, the great bulk of the experimental data is exact, although time may show that some of the experiments which were recorded before the technique was fully developed may require correction. Without questioning in the slightest degree the experiments reported by some of the skillful observers of modern times, one is, nevertheless, permitted to hesitate in adopting hypotheses that not only subvert formerly accepted ideas, but also seem, in many cases, inconsistent with one another.
The chemical world has been accused of accepting too dogmatically the theory of the conservation of matter, the indivisibility of the atom, etc. Ought we not, then, to guard ourselves against a similar fault in adopting newer views?
I propose to take up seriatim the methods of reasoning which have led to the present hypothesis of radiant matter as expressed by its chief exponents, and to indicate some points which seem to me to be inconsistent with older views, or in conflict with one another; and I shall begin with what may, from the present point of view, be called a static phenomenon, the behavior of the atom toward light. It is known that Lorentz modified Maxwell's electro-magnetic theory of light, by assuming that the vibrations from which light-waves originate are not produced by the atom as a whole, but rather by the vibration of its positive or negative electric charge, conceived as a special entity, which we may now personify, as it were, by the more recently coined name electron. The electron vibrates in an elliptical path which is really the result of two circular oscillations in opposite directions, and of differing amplitudes, but of identical period. An alteration of the radii of these circles would merely alter the shape of the ellipse; but if the periods of the two circular motions were made to differ, no single resultant could appear, for the two vibrations would produce waves of different length, i. e., light rays of different refrangibility. Now, a magnetic strain
- Extracts from a review presented to the New York Section of the American Chemical Society at its meetings, November, 1907.