322 PHENOMENA OF THE OCEAN. 
more feet ; and often immense flat-roofed ifi 
those of Luxor on the bank of the Nile, supported 
transparent columns of cerulean hue, float by tl’® 
gpectator. These icebergs are the creation of ‘ 
of^'rt;'^ 
acquire annually additional height by falls ot 
rain which latter often freezes instantly, and . > 
repairs the loss occasioned by the influence o> 
heat. 
LUMINOUS POINTS IN THE SEA- jj^i ^ 
Among the phenomena which have long oJd* 
sagacity of philosophers, that of the luniidd'^ 
ance of the surface of the sea, during ^jii 
of the night, is highly curious. A variety of 
tvere made by a French naturalist at Cayenne, 
seasons, to ascertain its tme cause ; and to him 
that these luminous points were produced by ,i 
friction alone, as he could not, with the help ° Pj 
glasses, perceive any insects floating in tlie "^<0 _ 
would seem, from the experiments and 
many learned men, that this phenomenon is 
various causes, both jointly and separately. ^ 
proved by one set of experiments, that the 
animal substances produces light and scintillatioO 
A little white fish jdaced in sea- water rendered ' ^ li^ j 
in the space of twenty-eight hours. On aoo ^j,pl'll^' 
it is certain tliat there is in the sea a prodigiom ^ 
shining insects or animalcules, which conU'be ^ 
phenomenon. A French astronomer, M. jl 
returned from Terra Australis in 1 774, brougln^,[,e))yr 
several kinds of worms which shine in water, 
set in motion ; and M. Rigaud affirms, tliat 
surface of the sea, from Brest to the Antilles, d 
immense quantity of little, lound, shining 
a quarter of a line in diameter. Other learned * 
acknowledge the existence of these luroinomp, p j 
cannot, however, be persuaded to consider *** 
cause of all that light and scintillation which 
surface of the ocean. They imagine that some s'* 
phosphoric nature, arising from putrefactm”' ,^ii 
admitted as one of the causes of this phenp** ^ 
other naturalists it has been ascribed to the oJy j]i f 
substances with which the sea is impregnated' 
