THE CHEMISTRY OF LIGHT PRODUCTION 141 



destroyed by the fat-solvent anaesthetics, such as chloro- 

 form, ether, etc. 



When Cypridina luciferin is oxidized, no fundamental 

 splitting of the molecule occurs, because the product, oxy- 

 luciferin, can be readilj^ reduced to luciferin again. This 

 reduction is brought about under conditions similar to 

 those necessary for the reduction of dyes, such as methy- 

 lene blue. Oxvlucif erin can be reduced to luciferin, which 

 will again give light with lucif erase, by the reductases of 

 muscle tissue, liver, etc., or by bacteria; by Schardinger 's 

 enzyme of milk; by H2S; by the nascent hydrogen from 

 the action of acetic acid on magnesium or of water or 

 NaOH on aluminium, zinc or magnesium; and by palla- 

 dium black and sodium hypophosphite, all well-known 

 reducing methods. Reduction of oxyluciferin no doubt 

 occurs even in presence of luciferase if oxygen is absent, 

 and reduction of oxyluciferin no doubt occurs in animals 

 which burn luciferin within the cell, thus tending for con- 

 servation of material. Dilute alkali favors oxidation and 

 dilute acid favors the reduction. Light favors the reduc- 

 tion of oxyluciferin. 



Apparently luciferin and oxyluciferin have identical 

 chemical properties. Neither is digested by the enzymes : 

 malt diastase, ptyalin, yeast invertase, pepsin, trypsin, 

 steapsin, amylopsin, rennin, erepsin, urease or enzymes 

 occurring in the water extracts of dried spleen, kidney, 

 or liver. Luciferase is destroyed only by pepsin (prob- 

 ably), tr^^Dsin, erepsin, and something in spleen and 

 liver extract. 



Luciferase is unquestionably a protein and all its 

 properties agree with those of the albumins. Although 

 used up in oxidizing large quantities of luciferin, 



