On the Characteristics of Highly Sensitive Discharge Points

Abstract

Discharge from Sensitive Points as a Function of Applied Voltage.—The points were prepared by grinding sewing needles to a fine point and then holding them an instant in an alcohol flame. The discharge always starts impulsively and the voltage at which this occurs, if gradually increasing potentials are applied, may differ greatly on successive trials, but is never below a value $B$ for a given point. A current once started persists when the voltage is lowered below $B$ but breaks suddenly at a definite potential $C$. If a voltage above $B$ is suddenly supplied to a point a current will eventually start after a time interval which on the average is the shorter the higher the voltage applied.