The sensitive surface of the Geiger tube electron counter

Experiments with the new Geiger tube electron counter show that no prepara- tion of the central wire electrode is necessary in contradiction to results reported by Geiger.Such wires as bare copper, bare steel, lacquered steel, oxidized tungsten, and oxidized nichrome work satisfactorily.All these wires cease to work when such gases as H2S, S02, ethylene, or water vapor are admitted.This shows that at the pressure at which these counters work sufficient oxygen is adsorbed to permit the counter to operate.When another gas with different adsorptive properties is admitted, the counter can no longer function.