ABSTRACT
The interesting result, obtained by M. Curie, of the exponential law of decay of the radium emanation under all conditions, is only one of many others that have now been accumulated. Quite agree with M. Curie that such results cannot be satisfactorily explained on the laws of ordinary chemical change, but the difficulty disappears on the view already put forward by Mr. Soddy and myself that the radioactivity of the elements is a mamfestation of sub-atomic chemical change, and that the radiations accompany the change. The no priori reason to suppose that temperature would affect the rate of atomic disintegration; in fact the general experience of chemistry in failing to transform the elements is distinctly opposed to such a view. It is therefore not surprising that, if radioactivity is an accompaniment of sub-atomic change, the process should be independent of the ordinary chemical and physical agents at our disposal.
