The Isolation of an Ion, a Precision Measurement of Its Charge, and the Correction of Stokes's Law

In a preceding paper 2 a method for measuring the elementary electrical charge was presented which differed essentially which had been used by earlier observers only in that all of the measurements from which the charge was deduced were made upon one individual charged carrier. This modification eliminated the chief sources of uncertainty which inhered in preceding determinations by similar methods such as those made by Sir Joseph Thomson 3, H.A. Wilson 4, Ehrenhaft 5 and Broglie 6, all of whom had deduced the elementary charge from the average behavior in electrical and gravitational fields of swarms of charged particles.