THE CHEMISTRY OF LIGHT PRODUCTION 111 



cence, that the light is probably due to the oxidation of 

 a compound, luciferin, in presence of air and water and 

 that the oxidation is accelerated by an enzyme-like sub- 

 stance, luciferase. We also saw in Chapter 2 that light 

 production is of fairly common occurrence during the 

 oxidation of many organic compounds, provided the oxi- 

 dation is carried out in the proper way. Many of these 

 organic compounds must be oxidized by relatively strong 

 alkali or such strong oxidizing agents as would have a 

 very deleterious action on living cells. In 1913, Ville and 

 Derrien, in a short note to the French Academy, ^ ' Catalyse 

 Biochemique d'une Oxydation Luminescente, ' ' show that 

 lophin could be oxidized by vertebrate blood in the pres- 

 lence and HoOg. In the same year Dubois (1913) found 

 that esculin, the glucoside from horse chestnut bark, would 

 also oxidize and luminesce in presence of blood and 

 HsOo. In these cases the haemoglobin of the blood acts as 

 a catalyst, transferring oxygen from the H0O2 to esculin 

 or lophin and is to be compared to luciferase, except that 

 luciferase does not require the presence of H2O2. 



As the haemoglobin does not lose this power on boiling, 

 whereas luciferase does, the analogy is far from perfect. 

 Many oxygen carriers are known, however, which may 

 be destroyed on boiling their solutions, namely, the per- 

 oxidases of plant juices. Esculin will not luminesce with 

 peroxidase and H2O2, but pyrogallol or gallic acid will. 

 If one mixes a test tube containing pyrogallol solution + 

 H2O2 with potato or turnip juice or almost any plant ex- 

 tract, a yellowish luminescence appears. The plant extract 

 loses the power to cause such luminescence on boiling and 

 the peroxidase will not dialyze. It is, of course, com- 

 parable to luciferase and acts on the thermostable, dialyz- 



