The Combination of Hydrogen and Oxygen in the Presence of Activated Mercury

Abstract

In order to demonstrate the ability of mercury atoms, excited by the absorption of the mercury line 2537 Å., to dissociate hydrogen by "collisions of the second kind," Cario and Franck [1] illuminated with a quartz mercury-arc lamp a mixture of hydrogen and mercury vapor in a quartz tube which also contained copper or tungsten oxide. The water formed in the reduction of the oxide by the activated hydrogen was removed by liquid air, and the consequent pressure decrease was followed with a MacLeod gauge. The writer has had occasion to make some similar experiments employing, however, gaseous oxygen instead of a metal oxide. In view of the importance of collisions of the second kind in other phenomena as well as in photo-chemical sensitization, the work will be briefly described.