HISTORY OF THE OYSTER. 27 



sold in the London market, are not fit for food. I 

 have seen the effects of eating out of season mussels, 

 which cause great derangement in the system ; but I 

 have not seen any one made ill by oysters, although 

 the same effects might be expected, and occurred at 

 Havre. The ' Green Oyster/ formerly in such high 

 repute, is now gone out of fashion, and those with 

 white beards are esteemed the most. The green colour 

 at Burnham, Mr. Sweeting informs me, is imparted by 

 a species of weed, growing on the beds ; this is pro- 

 bably not unwholesome : but there is another green 

 oyster, found on some portions of the Welsh coast, 

 which I should most decidedly think was ; it is said 

 to be coloured with copper from the mines. 



