THE QUANTUM YIELD OF HYDROGEN AND CARBON DIOXIDE ASSIMILATION IN PURPLE BACTERIA.

1. The effect of H(2) tension, CO(2) tension, pH, time, light intensity, density of suspension, salt content of the medium, and certain spectral regions on the rate of photoassimilation of H(2) and CO(2) by Streptococcus varians has been studied. 2. The method of making light absorption measurements with thin suspensions of bacteria is described. 3. A light source, optical system, and filter for isolating 852 mmicro with 894 mmicro in sufficient intensity for photochemical work and an improved design of thermostat are given. 4. The photoassimilation of 2H(2) with 1CO(2) apparently involves little over all energy change but nevertheless requires 4 quanta.