142 



STUDIES ON BIOLUMINESCENCE. XI 



Since 1 gm. of glucose liberates 4,000 calories on complete oxidation 

 to CO2 and H2O, it will be seen that the oxidation of luciferin is a 

 very different type of reaction from the oxidation of glucose. As I 

 have already suggested it is similar to the oxidation of reduced hemo- 

 globin or the oxidation of leucomethylene blue to methylene blue. 

 According to Barcroft and HilP 1.85 calories are produced per gm. 

 of hemoglobin oxidized. I have been unable to find figures for the 



0) 



75 

 o 

 to 





o 



> 



Id 





28.5 



28.0 



05 



g 27.5 



> 



•5 



3.40 

 Time 1n 



3.50 



minutes 



4.00P.11, 



Fig. 3. Curve showing temperature change when luciferin and luciferase solu- 

 tions at the same temperature are mixed. 0.1 galvanometer scale division 

 =0.003°C. Dots represent readings of thermo-couple in luciferin solution; 

 crosses, readings of thermo-couple in luciferase solution. 



heat exchange during oxidation of leuco dyes, but it is no doubt 

 also small. 



The production of carbon dioxide always involves the evolution 

 of considerable heat. Since luciferin evolves no measurable amount 



« Barcroft, M. A., and HiU, A. V., J. Physiol., 1909-10, xxxix, 411. 



