The Chemistry of Light-Production in Luminous Organisms. 225 



Trautz (36) has shown that if we mix 35 c.c. of a 50 per cent K2CO3 

 solution, 35 c.c. of 10 per cent pyrogallol, and 35 c.c. of 35 per cent 

 formaldehyde, and to this mixture add 50 c.c. of 30 per centH202, a glow 

 occurs, accompanied by much foaming. I can confirm this result, and 

 find in addition that when the glow has died, if we add some KMn04, a 

 reddish glow again appears. The tube becomes perceptibly warm. 



It is not necessary to use such strong reagents to obtain light from 

 oxidation of pyrogallol, however, for a very weak solution of pyrogallol 

 will give a bright light if oxidized under the proper conditions. The 

 oxidation of a mixture of pyrogallol + H2O2 by the vegetable oxidases 

 occurs with the production of light. The reaction is highly interesting 

 and remarkable for the following reasons: Perceptible light is pro- 

 duced with the concentration of pyrogallol m/32,000 — i. e., 1 part in 

 254,000 parts of solution; a faint light is produced at 0° C. and a bright 

 light at 10° C; KCN inhibits the reaction in m/2,000 concentration; 

 boiling destroys the oxidase, and the power of producing light just as 

 boiling destroys the light-producing power of organisms. 



THE CHEMILUMINESCENCE OF PYROGALLOL. 



It has been known for a long time that pyrogallol takes up oxygen 

 from the air in presence of alkali and is converted into brown oxidation 

 products of unknown composition. The depth of brown coloration 

 (and consequently the extent of oxidation) depends on the concentration 

 of alkali added. I have never under any conditions obtained light 

 during this oxidation, although concentrations of alkali ranging from 

 n to n/6,000 NaOH, both with and without H2O2, have been used. It 

 has also been long known that pyrogallol will turn brown with H2O2 

 and some oxidizing enzyme from organisms. Purpurogallin, a sub- 

 stance of doubtful composition (CnHgOs ?), is said to be formed and the 

 reaction has been used in studying oxidizing enzymes quantitatively. 

 Only if H2O2 be present will this reaction produce light. It is similar 

 to the oxidation of gum guaiac to guaiacum blue, but I find that guaia- 

 cum blue can be formed under many conditions when pyrogallol can 

 not be oxidized with light-production. Thus hydrogen peroxide is 

 necessary for light-production, even when potato-juice is used as the 

 oxidase solution — i. e., even when a juice is used containing an oxidase 

 which will oxidize guaiac tincture directlj^ (without addition of H2O2) . 

 It is then strictly a peroxidase which is responsible.^ Blood also gives 



^The difference between potato-juice, which oxidized guaiac without addition of H2O2, and 

 turnip-juice, which requires the addition of H3O2, appears to lie in the fact that the potato-juice 

 contains a substance which oxidizes spontaneously in presence of oxygen to a peroxide, while 

 the turnip-juice does not. Consequently, we must add a peroxide to the turnip-juice. Thi.s 

 spontaneously oxidizable substance was called oxygenase by Bach and Chodat. Both juices 

 contain peroxidase. The "direct oxidases" (of potato) consist, then, of peroxide (oxygenase) 4- 

 peroxidase, while the "indirect oxidases" (of turnip) are peroxidase alone. In this paper oxidase 

 is used as a general name for an oxidizing enzyme and peroxidase for an enzyme transferring 

 oxygen from a peroxide to an oxidizable substance. (See the account of this subject in B.iyliss's 

 Principles of General Physiol., 1915, 584; also see the monographs of Kastle (42), Warburg (Ergeb. 

 d. Physiol., xiv, 253, 1914), Batelli and Stern (Ergeb. d. Physiol., xn, <)i>, 1912), and Bach and 

 Chodat in Abderhalden's "Biochemische Arljeitsmcthoden, iii, No. 1, p. 42. Literature lists are 

 given in the first three monographs.) 



