The combination of nitrogen and hydrogen activated by electrons

The most recent of several papers on this subject is that of Caress and Rideal; they give a summary and discussion of the earlier work, and repetition here is unnecessary. Their paper will be taken as the starting point of the present one. In their experiments a mixture of nitrogen and hydrogen was admitted into a bulb containing a straight wire filament, which formed the axis of a cylindrical grid and anode. The space between these was the reaction space to which electrons of known speed had access from the filament. With electrons of suitable speed, a certain amount of combination took place, and the product, ammonia, was frozen out by surrounding the bulb with liquid air. The resulting fall in pressure, measured by a McLeod gauge, was a measure of the rate of reaction, and the chief part of their work was to examine the rate of reaction as a function of the electronic speeds.