The Chemistry of Light-Production in Luminous Organisms. 211 



fact that if 50 volumes of absolute alcohol are added to a mass of moist 

 centrifuged bacteria and they are then shaken for 10 minutes, the alcohol 

 removed, and bacteria quickly dried, no phosphorescence is obtained on 

 moistening this dry powder. Neither will dried bacteria phosphoresce 

 if extracted with 95, 80, 70, 50, or 37 per cent alcohol. What is the 

 explanation of this? The alcohol does not dissolve out a luminous 

 substance. Water appears to exert some influence. Perhaps we may 

 explain the above result as merely an example of the effect of alcohol 

 on dry albumins as opposed to albumin solutions. Powdered egg 



Table 13. 



Solvent. 



Ether (cold) 



Ether (hot) 



Chloroform (cold) 



Chloroform (hot) 



Ethyl alcohol (cold) 



Ethyl alcohol (hot) 



Alcohol and ether (equal part 



boiUng). 

 Acetone (cold) 



Acetone (hot) 



Carbon tetrachloride 



Carbon bisulphide 



Toluol 



Toluol (hot) 



Benzol 



Benzine (petroleum ether) . . . . 



Amyl alcohol 



Ethyl butyrate 



95 per cent alcohol 



80 per cent alcohol 



70 per cent alcohol 



50 per cent alcohol 



35 per cent alcohol 



Material kept dry at 



Material kept dry at 



Temperature 

 (in degrees O- 



20 



35 



20 



61 



20 



78.4 



46 



20 



56.3 



20 



20 



20 

 100 



20 



20 



20 



20 



20 



20 



20 



20 



20 



78.4 

 100 



Time of 

 extraction 

 (in hours). 



24 

 24 

 12 

 12 

 12 

 12 

 12 



12 



12 

 24 

 24 

 12 

 12 

 12 

 24 

 24 

 24 

 24 

 24 

 24 

 24 

 24 

 12 

 12 



Dried 

 bacteria. 



+ 

 + 

 + 

 + faint. 



— to faint 

 light. 



— to faint 

 light. 



+ fair, light. 



+ 



+ fair. 

 + fair. 



+ fair. 



Dried 

 firefly. 



+ 

 + 



Not tried. 



+ 



+ faint. 



+very faint 



albumin can be extracted with absolute alcohol (or acetone) for 6 hours 

 and is still readily soluble in water. But if a concentrated aqueous 

 solution of albumen is precipitated by a large excess of alcohol (or 

 acetone), even though the alcohol (or acetone) be removed within 

 15 minutes, the precipitate of albumen is found to be practically insol- 

 uble in water. It would be futile to discuss the matter without further 

 experimental results, but the results seem to indicate that in photo- 

 genesis there is involved a substance which in the moist state is irre- 

 versibly precipitated (or changed) by alcohol and that it is probably 

 protein in nature. 



At any rate, the experiments show (1) that the photogenic material 

 is not a fat or a fatlike body soluble in fat solvents, and (2) that phos- 

 phorescence does not depend on the living cell, since many of the dried 



