Indication of Hydroxyl in a Water Vapour Discharge Tube

Abstract

THE presence of OH in the gas coming from a water vapour discharge tube has been demonstrated by photographing the exit tube with a quartz spectrograph; the well-known band at 3060 A. was obtained. Addition of a small quantity of oxygen to the water vapour has the effect of increasing the intensity of the bands; a larger amount of oxygen causes the appearance of the green oxygen afterglow. This glow is continuous in the visible and is accompanied by the OH bands in the ultra-violet. The active gas appears to possess both reducing and oxidising properties. This is illustrated by the simultaneous reduction of copper sulphate to copper oxide and metallic copper and the oxidation of metallic silver. In both instances heat effects have been observed. The glow appears to be unaffected by the copper sulphate, but is removed by the silver. An extensive study of the conditions determining the production of OH, its separation from any other active constituents which may be present, and its chemical properties are now under way in this laboratory.