WILLIAM R. AMBERSON 



551 



In my first attempt to study the possibility of obtaining identical 

 decay curves with identical enzyme and luciferin solutions, I did not 

 use the double pipette which has been described, but started the 

 two reactions succef-sively, the one 16 seconds after the other, so as 

 to place the record*^ side by side upon the film. I found that the 

 resulting decay curves were not superposable, but in the straight 

 line plotting ran parallel to each other. It seemed reasonable to 

 suppose that in the intervening 16 seconds of time the spontaneous 



W) 



o 



40 



120 



80 

 Time 

 Fig. 6. True effect of different luciferin concentrations, 

 time in mm. along the film; ordinates, logarithm of intensity. 

 k for high concentration {A) = 0.737 

 k for low concentration {B) = 0.790 



160 



Abscissae represent 



oxidation in the second solution might have considerably reduced 

 the luciferin concentration in that solution, with a change of the 

 y-intercept of the straight fine, but not of the slope, as above discussed. 

 This experiment furnished the clue to a more satisfactory technique, 

 which does not permit, it is true, of securing accurate previous inf or- 



