THE PEARL OYSTER. 933 



The white are apt to degenerate to a very dingy yel- 

 low, after forty or fifty years' wearing. The Ceylonese 

 paint them with powder of pearls, and (as already men- 

 tioned respecting the mytilus margaritiferus] drill them 

 with great dexterity, so that they may be strung ready 

 for use. 



Pearls are valued according to the squares of their 

 weights. If a pearl of one carat be worth io/-, a pearl of 

 six carats will be worth thirty-six times as much, or ^"18 ; 

 for the square of 6, that is 6 multiplied by itself, is 36. 



The uninitiated are often deceived by buying, as 

 genuine productions of nature, articles which are mere fab- 

 rications, or artificial pearls. Some pretend to unite several 

 small pearls into one large one, which is impossible. From 

 the scales of some fish a silvery matter may be obtained : 

 this is dropped into a hollow bead of very thin glass, and 

 the appearance is so nearly that of the real pearl that none 

 but a practised eye can distinguish the difference. Nay, a 

 thin skin from the eye of the mackerel may be stamped 

 into a half-globular shape, which, when set, may deceive 

 the inattentive. The French are very dexterous imitators 

 of pearls, and the pastes they make of a certain powder, 

 united with isinglass, possess the weight, the lustre, and 

 nearly all the properties of real pearls. 



"The pearl-fisheries of Ceylon are under government 

 control and inspection, the coast being officially inspected 

 each season, The fishings may be let, or may be retained 

 in the interests of the government of Ceylon. Of late 

 years the Ceylon pearl-fisheries have been unproductive, 

 chiefly, it must be presumed, from over-fishing and the 

 want of definite knowledge respecting the habits of the 

 oysters, with a view to their cultivation and due preserva- 

 tion. In 1797, the first year in which the government 



