FISHES AND FISHING. 107 



pearly precipitate, and at one factory in France ten 

 thousand pearls were issued per week. Now the 

 Argentine or Tiber pearl fish, very like a smelt, but 

 not having its fragrant smell, supplies the material 

 for making these ornaments from their swimming 

 bladders, which are taken out and plunged into a 

 bottle of spirits of wine; when wanted, they are 

 macerated in a solution of isinglass, till all the pearly 

 particles are detached ; this is put into glass beads 

 of the size required, with a hole at each end, and 

 equally ditt'used, the holes being kept open, they are 

 then filled with hot wax, and, when cold, strung. 

 The largest bleak of which I can find any account 

 was taken at Cheshunt, 16th September, 1832; it was 

 seven and a-half inches long, as is recorded by Mr. 

 Baddeley, of Compton Street, GosweU Street. 



Leuwenhoek satisfied himself that the age of fish 

 could be discovered by the scales ; an annual fresh 

 lamina forms over the first scale, larger in every Wiiy, 

 corresponding with the growth of the fish, therefore 

 by separating these laminae, and the aid of a good 

 microscope, the age of the fish may be ascertained 

 pretty correctly, for fish do not shed their scales ; 

 those of the eel form a very beautiful subject for a 

 microscope having a high power. Monro states that 

 " the surface of the bodies of fishes, especially those 

 that live in the sea, is defended by a quantity of 



