OP CONCHOLOGY. 139 



The result is staged to have been in the negative. However 

 conclusive the observations of M. Valenciennes may appear, 

 Prof. Bizio, in a memoir read before the Institute of Venice in 

 the year 1845, calls attention to the fact that some ten years 

 previously he demonstrated the existence of copper in the 

 branchial organs of the Ostrea eduUs, at the time when a similar 

 discovery was made with reference to the spire of the Murex. 

 He says that he then hinted at the possibility of the green color 

 observed in the branchiae being the effect of the copper which 

 enters into the composition of that organ, and that he has been 

 confirmed in that opinion by these very experiments of M. Va- 

 lenciennes, which, he says, tend to make it evident to anybody 

 who knows anything about copper, that the coloring matter is 

 neither more nor less than that metal combined with, and dis- 

 guised in the organic substance of the oysters. 



It might be somewhat tedious to the reader were we to give a 

 detailed account of the experiments made by Prof. Bizio Avith a 

 view to prove this assertion. These experiments, he tells us, 

 were begun in June, and continued till the month of September. 

 They appear to have been conducted with great care and preci- 

 sion, and we would refer those anxious to pursue the investiga- 

 tion of this curious and interesting subject at greater length than 

 we have space to do at present, to Prof. Bizio's paper, which will 

 be found in the fourth volume of the " Transactions " of the 

 above named Academy. 



Suffice it to say that ammonia, which was one of the principal 

 tests employed by M. Valenciennes in his experiments, is also 

 the agent on which Prof. Bizio most relies ; and the results re- 

 corded by M Valenciennes as having been produced by ammonia 

 on the colored portions of the oysters, were, in part, due to the 

 presence of copper. 



It is remarkable that, while M. Valenciennes particularly 

 mentions the presence of the coloring matter in the intestinal 

 canal and liver of the oyster. Prof. Bizio's remarks refer only to 

 the branchige. Whether he would imply th;it the green color, 

 wherever it shows itself in the oyster, is due to the presence of 

 copper, is a query we are not prepared to answer, but should 

 like very much to have answered for us, as, bearing in mind the 

 cases at Rochefort, we cannot but think this green oyster ques- 

 tion rather a serious one. 



Fortunately there appears to be very little call for green 

 oysters in the English markets, and the great bulk of them are, 

 we believe, shipped over to France. Perhaps it is a good thing 

 they are so sparingly appreciated in this country. 



It is singular that so little should be definitely known of the 



