Recently the writer described a new method for studying the ionisation of gases by electron impact and presented the results of experiments on nitrogen. Similar data have now been obtained for hvdrogen and oxygen and form the subject of the present paper. Both apparatus and procedure were identical with those used in nitrogen and therefore will not be described in detail. But, perhaps, it may be as well to recall that the object of the method is to produce ions under the controlled energy conditions of an ionising potential experiment and at the same time determine their m/e by positive ray analysis. As to how this is achieved, we shall only say as much as seems necessary to make the results intelligible. Consider the schematic diagram in fig. 1.

Further studies in ionization: hydrogen and oxygen. (1924). Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 105(729), 116–128.