The Chemistry of Light-Production in Luminous Organisms. 



185 



The harmlessness of the above anesthetics for Cypridina photogenin 

 is unusual, as Dubois found a marked destructive action on Pholas 

 photogenin (lucif erase) and I have noted the same thing for the firefly. 



As we have just seen, the addition of certain anesthetics does not 

 rapidly destroy photophelein or photogenin. We can saturate a phos- 

 phorescent mixture of the two with ether and the light will still last 

 for some time. If we add butyl alcohol to saturation the light disap- 

 pears, and if the solution is now diluted with water or sea- water, the 

 light reappears. The same phenomenon is observed if the photogenin 

 be filtered through a Chamberland porcelain filter to remove all traces 

 of cells or cell fragments. Care was taken to make sure that the return 

 of light was not due to fluid adherent to the sides of the test-tube and 

 untouched by the butyl alcohol. 



TABLE o. Effect of preservatives on photogenin . 



A similar phenomenon is observed with ethyl alcohol and acetone. 

 If we add in small amounts absolute ethyl alcohol to a glowing mixture 

 of photogenin and photophelein, the light becomes very dim when 

 16 per cent alcohol has been added and disappears with 20 per cent 

 alcohol. If now the mixture be diluted, the light returns. Acetone 1 

 behaves as alcohol. About 23 per cent is necessary for extinction of 

 the light. Saturation with chloretone does not extinguish the light. 



The effect of ethyl alcohol and acetone might be explained as the 

 effect of precipitation, because of insolubility in the 20 per cent solu- 

 tion, but we can not so explain the extinction of the light by butyl 

 alcohol and subsequent recovery on dilution, since butyl alcohol is only 

 soluble to the extent of 8.3 parts in 100 parts of water. We are dealing 

 with a highly interesting effect one akin to anesthesia a reversible 

 inhibition, not of a cell or cell fragments, but of a solution. Filtration 

 through porous porcelain shows that no cell fragments can be present. 

 I can not here enter more fully into a discussion of this interesting 

 phenomenon, whose bearing on anesthesia is obvious, except to point 

 out that if we can anesthetize a solution we need not, as some recent 

 theories have done, regard changes in the cell-membrane to be neces- 

 sarily the ultimate cause of anesthesia. 



It may be pointed out in passing that the production of light gives 

 us the opportunity of observing the effect of, let us say, an anesthetic 



'The sample of acetone at hand was not particularly pure. 



