226 



Papers from the Department of Marine Biology. 



the reaction if H 2 O 2 is present. Catalase takes no part, and may be 

 destroyed by heating the potato-juice to 60. 



Thinking that this reaction might throw some light on lumin- 

 escence in organisms, I have studied it in some detail, with especial 

 reference to the substances which are known to affect light-production 

 in organisms. It is the oxidases, similar to those which blue guaiac, 

 that are concerned in the light-production of pyrogallol and potato- 

 juice, but, as we shall see, many inorganic catalyses are also able to 

 oxidize pyrogallol with light-production. It may be noted in passing 

 that although light can be produced at C., a considerable amount of 

 heat is given off, and in this respect the oxidation differs markedly 

 from those giving light in organisms. 



TABLE 20. 



In studying the reaction I have used mostly pure potato-juice (i. e., 

 the pressed, unfiltered extract of grated potatoes, strained through 

 cheese-cloth and decanted from the starch-grains) or a 1 per cent ox- 

 blood extract (i. e., 1 gram of dried defibrinated ox blood to 99 parts 

 water) added to an equal volume of a half-and-half mixture of m/100 

 pyrogallol and 3 per cent H 2 2 (Merck's perhydrol). The experiments 

 will be given in the form of tables or data under the following heads : 



1 . Concentration of the three substances necessary for light-production. 



2. Substances taking the place of blood or potato oxidase, pyrogallol, 



and H 2 02. 



3. Effect of temperature on the reaction. 



4. Effect of KCN, NaOH, and HC1. 



5. Effect of fat-solvent anesthetics. 



6. Is the oxidase a catalyzer? 



1. CONCENTRATION OF THE THREE SUBSTANCES NECESSARY FOR LIGHT-PRODUCTION. 



In general, the more concentrated the blood or potato-juice the 

 brighter the light, and the more concentrated the pyrogallol (to a limit) 

 the brighter the light, and the longer it lasts. Too strong pyrogallol 

 precipitates the blood-extract and potato- juice, the former in weaker 

 concentration than the latter (see table 20). In about m/8000 con- 

 centration the pyrogallol gives a bright light with potato-juice, and 



