ABSTRACT
The study of the collisions of α particles with hydrogen nuclei shows that the force between the α particle the H nucleus obeys Coulomb's law for large distances of collision. The force between the two particles increased much more rapidly with decrease of distance than could be accounted for on an inverse square law of force. When the incident a-particle had a range in air of less than 2.0 cm. the number of H particles projected in this specified direction was about that to be expected if the force between the particles was given by Coulomb's law. An H nucleus projected towards such an α particle would move under the ordinary electrostatic forces given by Coulomb's law until it reached a spheroidal surface. It would there encounter a very powerful field of force and recoil as from a hard elastic body.
