544 



KINETICS OF BIOLUMINESCENT REACTION. II 



usually practically identical in each pipette but variations in enzyme 

 strength of as much as 2 or 3 per cent may be produced in this way. 

 I have pre\dously discussed the magnitude of the errors known to 

 inhere in the photographic method itself. The question may well 

 be raised, however, as to how closely it is possible to secure identity 

 when simultaneous records are made using identical concentrations 

 of both enzyme and substrate. I have plotted the data obtained 

 in two such identical runs in Fig. 2. In practically all cases the 

 differences between the two readings are within the error of the photo- 

 graphic method. 



3. The Influence of Stirring. 



I have previously mentioned that, in spite of the known character 

 of the reaction, which is at least bimolecular, involving both luciferin 



0.0 



1.6 



W. Ij2 



23 



2.4 



so 



120 



40 



Time 

 Fig. 3. Effect of stirring. O stirred; • not stirred. Values check within 

 the error of the method. Abscissae represent time in mm. along the fihn; ordi- 

 nates, logarithm of intensity. 



