438 BLEAK CYPR1NE. Class IV. 



They are very common in many of our rivers, 

 and keep together in large shoals. These fish 

 seem at certain seasons to be in great agonies ; 

 they tumble about near the surface of the wa- 

 ter, and are incapable of swimming far from 

 the place, but in about two hours recover, and 

 disappear. Fish thus affected the Thames fish- 

 ermen call mad bleaks. They seem to be trou- 

 bled with a species of Gor^dius or hair-worm, 

 of the same kind with those which Aristotle* 

 says that the Ballerus and Tillo are infested with, 

 which torment them so, that they rise to the 

 surface of the water and then die. 

 Artificial Artificial pearls are made with the scales of 



Pearls. • 



this fish, and we think of the dace. They are 

 beat into a fine powder, then diluted with water, 

 and introduced into a thin glass bubble, which is 

 afterwards filled with wax. The French were 

 the inventors of this art. Dr. Lister -\ tells us, 

 that when he was at Paris, a certain artist 

 used in one winter thirty hampers full of fish 

 in this manufacture. 

 Descrip- The bleak seldom exceeds five or six inches 

 in length: their body is slender, greatly com- 

 pressed sideways, not unlike that of the sprat. 



* Hist. an. lib. VIII. c. 20. f Journey to Paris, 142. 



