On the kathode fall of potential in gases

Abstract

It has been shown by Hittorf that when an electric current pass through a tube containing a gas at a pressure of a few millimeter there is a rapid fall of potential near each of the electrodes, with much more gentle fall in the space between, and whilst the fall near the anode and in the positive column varies with the density of gas and the current strength, the fall near the kathode is constant Warburg has made careful experiments on the kathode fall, and is fully established its constancy. If the gas is pure and dry, electrodes clean, and of a metal not acted on chemically by the gas the current not so strong as to make the negative glow cover the role kathode or extend to the walls of the tube, the kathode fall a definite value for each gas—a value that is independent of the pressure of the gas, or of the current strength, and that appears, in to be a constant of the gas.