232 Papers from the Department of Marine Biology. 



SIGNIFICANCE FOR BIOLUMINESCENCE. 



The reader has doubtless already noticed the similarity of the pyro- 

 gallol+H202-peroxidase reaction and the luciferin-lucif erase reaction 

 of Dubois. Just as Dubois supposed luciferin to be oxidized by luci- 

 f erase, so we actually find pyrogallol+HsOa oxidized by peroxidase. 

 We now know that luciferin (photophelein) is not oxidized by luci- 

 ferase (photogenin) but that Dubois's luciferase is actually the source 

 of the light of luminous animals; so that the luminescence of pyrogallol 

 turns out to bear only a superficial resemblance to that of organisms. 

 Pyrogallol +H2O2 will give no light with either photogenin or pho- 

 tophelein, nor will peroxidase give light with either photogenin or 

 photophelein, even if we add H2O2. However, it is interesting and 

 important to know that certain substances found in plants and animals 

 can assist in oxidizing other substances found in plants and animals 

 with the production of light. The light produced in these cases is 

 faint compared with the light produced by luminous organisms or 

 compared with the light produced by substances from luminous organ- 

 isms in a test-tube, but nevertheless it is light with very little heat, and 

 perhaps a further survey will reveal the existence of definite compounds 

 producing light in a manner more closely resembling that of Cypridina. 

 As has been shown by Trautz (36) the spectrum of luminescent pyro- 

 gallol is continuous but shorter than the normal spectrum, so that 

 there is marked similarity in the physical characteristics of the light 

 of chemiluminescent substances and of luminous organisms. 



SUMMARY OF STUDY OF CHEMILUMINESCENT REACTIONS. 



1. Pyrogallol gives off a yellowish-white light about equal in inten- 

 sity to a suspension of luminous bacteria when oxidized by blood or 

 plant-juices (oxidases) in presence of H2O2. 



2. The light is visible in very weak concentrations of pyrogallol, viz, 

 m/32,000 or 1 part to 254,000 parts solution. H2O2 must be present in 

 at least 0.025 per cent, blood in 0.1 per cent (dried defibrinated blood), 

 potato-juice in 5 per cent (fresh pure juice), to give a just visible light. 



3. Of many easily oxidizable hydroxy- and amino-phenols only 

 pyrogallol gives light. K4Fe(CN)6, KMn04 or FeCls, K2Cr207, K2Cr04, 

 MnOs, Mn(OH)2+Mn(OH)3, HaMnOa, Fe2Fe(CN)6, Ag20, and colloidal 

 Pt, Au, and Ag will all give light with pyrogallol. Extracts of inverte- 

 brates, except those of Chiton, a few marine annelids, and the blood of 

 a squid (Sepia) and a marine crayfish (Panulirus) , do not give light. 

 Na202, Ba02, Pb02, benzoyl H2O2, quinone, or ozonized turpentine 

 will not take the place of H2O2. 



4. Light is produced at 0° C. and a bright light at 10° C. The oxi- 

 dase of plant- juices is destroyed between 80° and 85° C. 



5. KCN inhibits the light-production in very weak concentration, 

 m/1280 to m/2560. NaOH inhibits in n/40 and HCl in n/80 con- 

 centration, but these figures give no idea of the H-ion concentration. 



