932 OYSTERS, AND ALL ABOUT THEM. 



but when they begin to putrefy they fly open, and, of 

 course, the pearls are taken out without injury, They are 

 then placed in troughs made of the trunks of trees, hol- 

 lowed, and sea-water is thrown over them. The pearls 

 are now readily shaken out and washed, by men who stand 

 on one side of each of the troughs. The largest are care- 

 fully picked up, and washed repeatedly with clean water ; 

 the next in size and quality are merely taken from the 

 trough, and spread out on white napkins to dry in the sun ; 

 and it is not till this is done that any attention is paid to 

 the smallest pearls, which are generally left to the care of 

 the women, who pick them up and dry them. The shells, 

 after being cleaned, are split into layers for the sake of the 

 nacre of which they are composed. This nacre is com- 

 mercially known in three forms the " silver-lipped ' ; of 

 India, China, and Peru ; the " bastard- white/' and the 

 " bastard -black " nacre. 



The first mentioned is the most valuable ; it is im- 

 ported in cases weighing from 25olbs. to 28olbs. each. 



The second kind of nacre is imported in casks of 

 about 25olbs. weight ; this latter variety is coloured yel- 

 lowish or greenish, or may exhibit reddish or bluish tints. 

 The nacres are used chiefly for the purpose of inlaying 

 wood and marqueterie work. Pearls should be of a clear 

 white, and highly glistening ; this lustre is called their 

 water. So we say in Europe ; but in the East those tinged 

 with a little yellow are preferred, especially as they are 

 reported never to change their colour. 



The Cingalese prefer those which are rose-coloured, 

 and the Indians and some other orientals the yellow pearls. 

 Besides pearls of these three colours, others are found 

 of a delicate blue tint, while some have a golden and others 

 a silvery hue. 



