432 ANNUAL RECORD OE SCIENCE AND INDUSTRY. 



water, which is generally much purer than the lower portions. 

 As a herbivorous fish, the orph has the advantage of not in- 

 terfering with trout or salmon in a stream ; and, indeed, as it 

 multiplies with great rapidity, would be an excellent associ- 

 ate for such species, in furnishing to them an important ar- 

 ticle of food. D. Fischer ei-Verein Circular, 1872, iv., 102. 



GREEN COLOR OF OYSTERS IN CHESAPEAKE BAY. 



A dealer in Washington not long since found a large num- 

 ber of the oysters from a certain region in Chesapeake Bay 

 with the gills of a decidedly green color, and on this account 

 they were considered unmarketable. Specimens of these were 

 sent for examination to the Army Medical Museum, where 

 they were examined microscopically by Dr. J.J.Woodward, 

 who found nothing abnormal whatever in the way of fungus 

 growth, or as indicating the presence of parasites, or any 

 form of disease. 



They were then submitted to the chemical investigation of 

 Dr. Craig, the chemist of the establishment, and, on testing 

 them by means of the spectroscope, minute traces of copper 

 were detected, but not in sufficient quantity to account for 

 the color, nor to indicate danger from this source. The green 

 color of oysters is by no means unusual in other parts of the 

 world, especially in Europe, and there it is not considered as 

 suggesting a condition of the animal injurious to the health 

 of those who eat them. Indeed, the Marennes oysters owe 

 their reputation to this particular quality. 



VIRGINIA OYSTER FISHERY IN 1871. 



The chief of the Virginia oyster police has just made his 

 report for 1871 to the state Legislature, in which it is stated 

 that only the sounds of Tangier and Pocomoke are subject 

 to dredging, and that these, exclusive of the river and creeks, 

 cover an area of 9740 acres. It is now recommended that 

 dredging in them be prohibited for a certain period. The 

 rest of the Chesapeake, exclusive of rivers and creeks, covers 

 an area of nearly 435,000 acres, averaging some six fathoms 

 in depth. On this dredging is interdicted, the oystering being 

 done only with tongs. The commodore advises that dredging 

 be allowed in the Chesapeake, except Tangier and Pocomoke 

 Sounds, especially as this operation in proper amount is bene- 



