246 VIEWS, &C. PHYSIOGNOMY OF PLANTS. 



especially in the Pacific, can form but a very imperfect idea 

 of the majesty of this brilliant spectacle. The traveller on 

 board a man-of-war, when ploughing the foaming waves before 

 a fresh breeze, feels that he can scarcely satisfy himself with 

 gazing on the spectacle presented by the circling waves. 

 "Wherever the ship's side rises above the waves, bluish or 

 reddish flames seem to flash lightning-like upwards from 

 the keel. The appearance presented in the tropical seas 

 on a dark night is indescribably glorious, when shoals of 

 dolphins are seen sporting around, and cutting the foaming 

 waves in long and circling lines, gleaming with bright and 

 sparkling light. In the Gulf of Cariaco, between Cumana 

 and the Peninsula of Maniquarez, I have spent hours in 

 enjoying this spectacle. 



Le Gentil and the elder Forster ascribed these flames to 

 the electrical friction of the water on the vessel as it glides 

 forward — an explanation that must, in the present condition 

 of our physical knowledge, be regarded as untenable.* 



There are probably few subjects of natural investigation 

 which have excited so many and such long- continued con- 

 tentions as the phosphorescence of sea- water. All that is 

 known with certainty regarding this much disputed question 

 may be reduced to the following simple facts. There are 

 many luminous mollusca which possess the property when 

 alive of emitting at will a faint phosphoric light; which is of 

 a bluish tinge in Nereis noctiluca, Medusa pelagica var. /3,f 

 and in the pipe-like Monophora noctiluca, discovered in 

 Baudin's expedition. \ The luminosity of sea- water is in 

 part owing to living light-bearing animals, and in part to 

 the organic fibres and membranes of the same, when in a 

 state of decomposition. The first-named of these causes 

 of the phosphorescence of the ocean is undoubtedly the most 

 common and the most widely diffused. The more actively 

 and the more efficiently that travellers engaged in the study 



* Joli. "Rcinli. Forster, Bemerlcungen auf seiner Reise wm die Welt, 

 1783,s.57; Le Gentil, Voyage dans les Mers de VInde, 1772, t. L 

 pp. 685—698. 



f Forskaal, Fauna cegyptiaco-arahica, s. Descriptions animalium 

 qaai in itinere oricntali observavit, 1775, p. 109. 



% Bory de St. -Vincent, Voyage dans les lies des Mers d'Afrique, 

 1804 t. i. p. 107, pi. vi. 



