THE CHEMISTRY OF LIGHT-PRODUCTION IN LUMINOUS 



ORGANISMS. 1 



BY E. NEWTON HARVEY. 



INTRODUCTION. 



The literature on the subject of animal phosphorescence or biolum- 

 inescence or biophotogenesis is so voluminous that no attempt can be 

 made in the present article to record a complete list. A fairly com- 

 plete bibliography will be found in Mangold's article, "Die Production 

 von Licht," in Winterstein's Vergleichende Physiologic. The names of 

 Beijerinck, Dubois, Ehrenberg, Krukenberg, Mangold, McDermott, 

 Molish, Panceri, Phipson, and Quatrefages are intimately connected 

 with the chemical and physiological side of light-production. The 

 work which has been accomplished up to the present time indicates that 

 light-production by animals is to be classified among the chemilum- 

 inescent reactions which have been studied from the purely chemical 

 side, especially by Radziszewski and Trautz. All of the evidence now 

 indicates that oxygen is necessary for this reaction at least the state- 

 ment is true for the following investigated forms: the fireflies; lumi- 

 nous bacteria and fungi; Noctiluca (2) ; apennatulid (Cavernularia) ; and 

 an ostracod crustacean (Cypridina) . It has been objected by some 

 that if we place the organisms, say luminous bacteria, in an atmosphere 

 devoid of oxygen and find that no light is produced, that merely means 

 that certain functions of the cell are interfered with, including light- 

 production, but does not indicate that oxygen is actually used up in 

 the photogenic process. The objection will not hold, however, for 

 extracts of luminous cells or the luminous secretion of Cypridina, which 

 contains the light-producing substance in solution (so that it can not 

 be removed by filtration through a porcelain or siliceous filter) will give 

 no light if the oxygen be removed, and light returns when oxygen is 

 readmitted. 



We may therefore say that a definite substance is burned (oxidized) , 

 and in some forms it burns as granules and in others as a homogeneous 

 and probably colloidal solution. This substance is stable and non- 

 luminous when dried and is not a fat or any substance soluble in fat 

 solvents. It has been called noctilucin by Phipson (6 and 7), photogen 

 by Molish (s), luciferin by Dubois (9), and photogenin by myself. 

 Phipson and Molish did not recognize that in many forms two sub- 



lr This paper is a compilation with additions and some changes of my work on luminous forms 

 during the past three years. The original papers will be found grouped together in the bibliog- 

 raphy (1), and are not specifically referred to in the text. 



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