ABSTRACT
As Mr. Henderson was unable to complete this work in the Caven-dish Laboratory before leaving for Canada, Rutherfold undertook to verify his conclusions by the scintillation method. Experiments were then made to examine quantitatively the ratio between the number of singly and doubly charged particles for different velocities of the α rays. It will be seen that the α particle in passing through matter occasionally captures an electron and this electron may be subsequently lost by collision with the molecules. It is clear however from these results that the average α particle captures and loses an electron several hundred times before absorption. Certain observations have been made which seem to show that one α particle may differ from another in its power of capturing or losing an electron. The observations made by Mr. Henderson on the capture of electrons by flying particles have opened up a new and interesting field of enquiry.
