The Quenching of Mercury Resonance Radiation by Foreign Gases

Maline's Theory of the diffusion of imprisoned resonance radiation is applied to Stuart's experiments on the quenching of Hg resonance radiation by foreign gases, and expressions obtained for $n_2$, the number of excited Hg atoms per cc, and $J$, the quenching, in terms of $k$, the number of impacts of the second kind per sec per excited atom. Stuart's experimentally determined values of $J$ are used to give the relation between $k$ and the pressure of the foreign gas, and the result is obtained that the number of impacts of the second kind per sec per excited atom is not a constant fraction of the total number of collisions. The total number of impacts of the second kind per cc is calculated and taken as the reaction velocity, and upon plotting against the pressure it is shown that the reaction velocity varies as the 0.6 power of the pressure for all the foreign gases. It is shown how these results can be explained on the theory that impacts between excited Hg atoms and foreign gas molecules give rise to metastable Hg atoms, which diffuse to the incident wall and meet there adsorbed foreign gas molecules to which they give up their energy. This theory is also capable of explaining the behavior of a large quantity of inert gas on the dissociation of hydrogen and oxygen by excited Hg atoms.