The nature of the evidence for the divisibility of the electron

The purpose of this note is to remove misconceptions due to erroneous statements regarding the determination of the elementary electronic charge by the oil-drop method. It is emphasized that the existence of an elemental charge is directly proved by the multiple relationship shown to exist between successive charges on each test particle; that the unitary character of electricity is not pre-supposed even in determining the absolute value; and that the method used by Sexl in determining the radius of the droplet is not essentially new. Recent photo-electric work of Hake and of Wasser is discussed briefly.