ABSTRACT
The transformation of each atom results from an atomic explosion of an exceedingly violent character, and in general results in a liberation of energy many million times greater than from an equal mass of matter in the most vigorous chemical reaction. It is now well established that the radio active substances are undergoing spontaneous transformation, and that their characteristic radiations the Td1, β, and γ rays accompany the actual disintegration of the atoms. In the majority of cases the atomic explosion is accompanied by the expulsion of an actual atom of matter an a particle with a very high speed. A brief account was given of the recent work of Rutherford and Robinson in determining with accuracy the velocity of expulsion of the particles from certain radio-active substances. During the last few years notable advances have been made in our knowledge of the mode of emission of β particles from radio-active atoms.
