On the Economical Uses of some species of Tesiacca. 69 



neglected, increased in price greatly beyond their value, and superior 

 often to the price of oriental ones when bought in the east.* At 

 present we are not aware that they are sought for, except as curi- 

 osities. 



Natural history. — This shell is common to most of the rivers of 

 Europe, but is chiefly found in those which are violent and rapid, 

 and in the temperate or colder climates. In Norway and Sweden 

 they abound, and they are found plentiful in the streams of West- 

 ern Siberia.f In Great Britain they are common in the English, 

 Welsh, and Scotch, and some of the Irish rivers ; in all which the 

 fisheries were formerly prosecuted. The same opinion as to the 

 formation of the pearls in these was held, as with respect to the 

 last species; and the supposition, that they were formed of dew, or 

 of eggs which had not been evacuated, was supported by scientific 

 writers as late as the seventeenth century. 



In 1761 Linnaeus informed the King and council of Sweden that 

 he had discovered an art by which muscles might be made to pro- 

 duce pearls, and he offered to disclose the method for the benefit of 

 the kingdom. This however was not done, but he disposed of the 

 secret for about five hundred ducats to a German. At the death of 

 this man it was offered for sale, sealed up to the highest bidder, but 

 w^bat became of it is not known. Linnseus once showed Beekman a 

 small box fiJled with pearls, and said, " Hos uniones confeci ariificio 

 meo, sunt tantiim quinque annornm,, et tamen tarn magni ;" and he 

 declared that he could succeed in the same manner with all kinds of 

 muscles. J They lie in the mud, generally sticking up in a horizon- 

 tal position by one end. 



Fisheries. — Lying generally in shallow water, little exertion or 

 skill is necessary in procuring them, and the business was probably 

 never sufficiently extended or valuable to cause either their cultiva- 

 tion or particular protection. The manner practised in procuring them 

 in the north of Ireland in 1660, is described in the Philosophical Trans- 

 actions, and exhibits neither art, nor much intelligence. In the warm 

 months before the harvest, while the rivers were low and clear, the 

 poor people waded into the water, and some with their toes, some 

 with wooden tongs, and others with a sharpened stick, thrust into 

 the open shell, brought them to the surface ; and although by com- 



* Macpherson, III. 419. Bruce, VII. 321. 



t Cochrane'.s Pedestrian Tour. . t Beekman, II. 5 — 11. 



