124 



The Maximum Efficiency of Photosynthesis 



III. Start of 3rd measurement 



June 15, 4:50 p. m. 



The cells were washed in fresh culture medium because in the old medium the efficiency of 

 the light appeared to decrease. 



No. 5 



No. 3 



10' dark — 17.5 

 10' dark— 16.0 

 10' dark — 16.5 

 10' dark— 15.5 

 40' dark — 65.5 

 30' dark — 49.2 



10' AJ — 10.0 

 10'. J7- 8.5 

 10' AJ- 7.5 



30' AJ — 26.0 



30' H' + 23.2 



30' H + 8.3 



yo 2 = - 48.5 cu. mm. 

 yco2 — — 62 cu. mm. 



I A 3 x 30 



~ 48.5 



= 1.28 



3.4 



The respiration at the beginning of the experiment was 82",, of the cell volume Oo/hr., and 

 at the end of the experiment 45",, of the cell volume O-2/hr. The washing of the cells in fresh 

 culture medium had no influence on the respiration. 



The experiment shows that the efficiency of light remained nearly constant when the cells were 

 continuously illuminated with white light for more than 20 hr. 



Experiment 7 



June 16, 1949 



5% CO-2 in air. The cells were washed with KNOs-free culture medium (pH 5) and the efficiency 

 was measured in KN0 3 -free culture medium. Later KNO3 was added and the efficiency was again 

 measured. 300 cu. mm. of cells in each vessel. 



AJ = 5.4 

 No. 5 No. 3 



