Gasesous combustion in electric discharges. Part VI.—The effect of diluents upon the cathodic combustion of carbonic oxide “detonating gas”

A spectrographic examination of the cathodic combustion of carbonic oxide “detonating gas” has shown that carbonic oxide ions are not formed in either the cathode or interelectrode zones under the conditions of our experiments (V). This fact proves that carbonic oxide molecules can be burnt cathodically without being ionised. The observed acceleration of the rate of cathodic combustion of “detonating gas” by steam and/or metal particles cannot, therefore, be attributed to the overcoming of the electrostatic forces of repulsion existing between similarly charged ions (III and IV). The present investigation was originally undertaken with the object of submitting certain of our earlier views to the test of experiment. During its prosecution, however, Prof. S. Chapman, F. R. S., suggested to us that considerations arising out of the three-body collision theory might lead to a satisfactory explanation of the mechanism of the combustion of “detonating gas”; and since then the investigation has been considerably extended in order to enquire more closely into the precise nature of the rôle or rôle played by such promoters of cathodic combustion as metal atoms and steam molecules.