THE EFFECT OF CERTAIN ORGANIC'AND INORGANIC 



SUBSTANCES UPON LIGHT PRODUCTION 



BY LUMINOUS BACTERIA. 



E. NEWTON HARVEY. 

 PRINCETON UNIVERSITY. 



While engaged in a study of the chemistry of light production 

 by luminous bacteria I had occasion to investigate the effect of 

 diluting the sea water with distilled water and with isotonic 

 sugar solution and the influence of the various salts of sea water, 

 of acids and alkalies, and of certain anaesthetics upon the emission 

 of light. The results are of interest for comparison with the 

 known effects of these substances on other organisms and with 

 other vital manifestations of life. 



In all experiments, except where otherwise noted, one drop of 

 the dense emulsion of luminous bacteria (a form isolated from 

 squid at Woods Hole, Mass.) was added to 30 c.c. of solution in 

 an uncorked Erlenmeyer flask and the whole thoroughly mixed. 

 For comparative observations it is essential that the eye be thor- 

 oughly adapted to the dark and that each flask be oxygenated 

 by shaking, before judging as to the emission or absence of light. 

 Observations were made after 10 minutes, one hour and 24 hours. 



TABLE I. 



EFFECT OF DILUTION OF SEA WATER WITH WATER AND WITH m CANE SUGAR 



SOLUTION. 



308 



