470 ON THE LUMINOSITY OF THE SEA. 



the light, as in the former case, was the cause. It 

 is supposed, that the Scolopendra electrica, is de- 

 stroyed by exposure to solar light ; and Mr Mac- 

 eartney observes, that the medusae always retreated 

 from the surface as soon as the moon rose ; and he 

 also states, that exposure to day-light deprived them 

 of the power of shining. 



By stirring the salt-water containing the medusa, 

 occasional gleams were exhibited. I then transfer- 

 red it to a basin of fresh water, when it sunk to the 

 bottom like a falling star. The effect here, was of the 

 most beautiful description. There appeared strings 

 of minute beads of fire, like a chain illuminated by 

 electricity. By stirring the fluid, these luminous 

 points were disentangled, and exhibited a pretty 

 hemisphere of stars. These floating fires soon ceas- 

 ed to lighten the fluid mass ; agitation could not 

 restore the effect, though a few drops of acid caused 

 a solitary gem to twinkle. The medusa was trans- 

 parent and gelatinous like the other. There can 

 be no doubt, but that it was the tendrils or feelers 

 which were vested with this brilliant and beautiful 

 ornament ; and I presume, that these living fires 

 originated here as in the ciliary processes of the 

 beroe ; and that they were, subsequently, by some 

 peculiar mechanical impulse, transfused over the 

 transparent membranous sac or disc. 



We dare scarcely speculate, touching the design 

 of the primary distinction. This much we know, 

 that Almighty Goodness has made nothing super- 



