LUMINOSITY OF THE SEA. 153 



Their twittering, and the motions of their wings, are, however, heard 

 during the whole night. As soon as the day begins to dawn, they rise, 

 flying low over the lakes, almost touching the water for some time, 

 and then rising gradually move off in search of food, separating in dif- 

 ferent directions. The hunters, who resort to these places, destroy 

 great numbers of them, by knocking them down with the light paddles 

 used in propelling their canoes. 



ON THE LUMINOSITY OF THE SEA. 



BY BARON DE HUMBOLDT.* 



IN the immense waters of the deep, animal life is very profusely 

 distributed, and particularly gelatinous worms are so numerous, as to 

 bestar the surface of the ocean and transform it into a sea of flames, 

 a spectacle which stamped upon my memory an ineffaceable impres- 

 sion, and always excited fresh astonishment, although it was renewed 

 every night for months together. It may be seen in every zone ; but 

 those who have not witnessed it within the tropics, and above all upon the 

 main ocean, can form but a very imperfect conception of the grandeur 

 of the phenomenon ; particularly if the spectator places himself in the 

 shrouds of a ship of the line, during a fresh breeze, when she ploughs 

 through the crests of the waves, and, at every roll her side is raised out 

 of the water, enveloped in ruddy flames, which stream like lightning from 

 the keel, and flash towards the surface of the sea. At other times, the 

 dolphins, while sporting in the waters, trace out sparkling furrows in 

 the midst of the waves. 



Le Gentile and the elder Forster, explained the phenomena of these 

 flames, by the electric friction of the waves against the hull of the 

 ship, as it advances. But, according to our present knowledge 

 of physical causes, this explanation is inadmissible. 



There are few points of natural history which {fave been so long and 

 so much disputed, as the illumination of the sea water. All that is 

 known with any certainty, may be reduced to the following facts : 

 there are several shining mollusca which, during their life, emit at 

 pleasure a phosphoric light, which is rather pale and generally of a 

 bluish colour ; this is observed in the Nereis noctiluca, the Medusa 



* Translated from the German, 



