BY INFERIOR ORGANISMS. 123 



ralists, who made a scientific voyage round the 

 world in the ship ( La Bonite/ observed that cer- 

 tain small phosphorescent Crustacea sometimes 

 secrete a peculiar phosphorescent matter, and 

 that when they are irritated, they send forth mag- 

 nificent flashes of light. Other crustaceans did 

 not appear to possess this faculty. These two 

 gentlemen collected a certain quantity of the 

 phosphoric substance ; they found it to be " yel- 

 lowish, viscous, and soluble in water/' communi- 

 cating its luminous property to this liquid, but 

 only for an instant or two. It lost its luminosity 

 when it had been separated for a few moments from 

 the body of the animal. 



These naturalists have also observed the phe- 

 nomenon of phosphorescence in certain Pteropoda 

 and Cephalopoda j they believe that these animals 

 possess a peculiar phosphorescent substance like 

 that of the Crustacea, which, from their observa- 

 tions, appears to be continuously and uniformly 

 luminous as long as the animals live, but ceases 

 to be so when they die. 



When the phosphorescent Infusoria, of which 

 I have spoken, are exhausted and cease to emit 

 any light, their luminous faculty can be restored 

 for a while by exciting them with a drop of dilute 

 acid or alcohol mixed with the sea-water; but 

 this experiment soon kills them. 



Humboldt affirms that having placed certain 



