The volume of gaseous oxygen produced during the Bray-Liebhafsky (BL) oscillating reaction was measured. The rates of oscillatory O-2 evolution were calculated and the geometrical effects of the Pt electrode surface, stirring rate, and addition of the surfactant on the oscillatory behavior were studied. A significant stirring rate and detergent effect is observed. The oxygen evolution results obtained are in satisfactory agreement with oscillatory behavior of the BL reaction monitored by potentiometric measurements. The idea that physical and chemical processes might couple in the gas evolving oscillators and similar systems was first suggested over fifteen years ago by Bowers and Noyes. The possibility that chemical processes may couple with both oxygen and iodine nucleation and evolution in order to cause, enhance, or suppress oscillations in the BL system is indicated.