176 PHOSPHORESCENCE. 



Experiments, the results of which appear con- 

 tradictory, were made upon the glowworm' s light, 

 by Forster, Spallanzani, Dr. Hulme, Beckerheim, 

 and Humphry Davy. Davy's experiments show 

 that the light was neither increased in oxygen or 

 extinguished in hydrogen gas (Phil. Trans. 1810). 

 It was in 1749 and 1750, as we have seen, that 

 Professor Viannelli and Dr. Grixellini discovered, 

 in the Adriatic Sea, their small luminous worm, 

 Nereis noctiluca ; and from this moment the real 

 cause of the phosphorescence of the sea was esta- 

 blished. It was then owing to animalcules ! Soon 

 afterwards Captain Cook and Mr. Forster met 

 with those curious little organisms, the Noctilucce, 

 and recognized them as the cause of the phospho- 

 rescence of the ocean. In 1776, the Abbe Spal- 

 lanzani treated of the phosphoric light emitted 

 by Medusa. 



Since then, discoveries connected with phos- 

 phorescence have multiplied considerably up to 

 the present day. 



The history of that of our own Noctiluca miliaris, 

 which illuminates the waters of the English Chan- 

 nel, and therefore interests us particularly, is curi- 

 ous enough. 



This animalcule was accurately observed, for 

 the first time, by a French naturalist, Rigaud, in 

 1765, who speaks of it in the 'Memoires de 

 FAcademie de Paris/ it was seen also, about the 



