WILLIAM R. AMBERSON 555 



of leuco-methylene blue, a single molecule undergoes dehydrogenation 

 according to the form 



M-H2 +0 = M + H2O. 



The present data are somewhat more difficult of interpretation 

 when we turn to the conditions obtaining during the first few seconds 

 of the reaction, for here we find a bright initial flash out of all accord 

 with the succeeding values, and thereby masking the beginning of 

 the reaction. 



As far as I am aware, no report has ever been made, or perhaps 



has ever been possible, upon the reaction velocity of any organic 



catalysis during the first few seconds of its course. The reaction 



under consideration is unique in affording information as to reaction 



velocity at every instant along its course, and the photographic 



method which I have employed has given clear evidence concerning 



the rather striking character of the bright initial flash. The kinetics 



of no other enzymatic process that I know can be studied in any such 



dx 

 direct way. In none other can the — of the reaction be immediately 



dt 



measured. It appears that this luminescent reaction may be thus 



peculiarly fitted for the making of further quantitative studies bearing 



upon enzyme theory. 



I am convinced that the occurrence of the bright initial flash has a 



considerable theoretical significance. It has at times been observed, 



in the study of inorganic heterogeneous catalysisi^ that there may 



occur high initial reaction velocities similar to that of the luminescent 



reaction in Cypridina. Such phenomena may be interpreted as due 



to the fact that at the very beginning of the reaction, the surfaces 



of the catalyst are clean, allowing a rapid adsorption of the substrates 



and a high reaction velocity. These initial conditions speedily 



vanish, for the collection of the resultants at the surfaces rapidly 



decreases the active masses, until an equilibrium is established 



between diffusing resultants, and new active material reaching the 



surfaces. The reaction then slows down, and straightens out into a 



consistent form which governs its later course. 



* Unpublished work from the Department of Chemistry, Princeton University. 



