THE CHEMISTRY OF " OYSTER-FATTENING:' 79 



States Fish Commission, and -vrbich included examinations of a num- 

 ber of sj^ecimens of oysters and other shell-fish, I have improved the 

 opportunity to test this matter by some analyses of oysters before and 

 after floating. The results of the investigation are to be given in de- 

 tail in one of the publications of the Commission,* in which the prin- 

 ciples involved and some side-issues of tbe experiments will be dis- 

 cussed. I give here the main results, prefacing by brief accounts of 

 the process of " floating " oysters as actually practiced by oyster-men. 

 The following very apposite statements f are by Professor Persif or 

 Frazer, Jr., who attributes the changes mentioned to dialytic action : 



The oysters brought to our large markets on the Atlantic seaboard are gen- 

 erally first subjected to a process of " laying out," which consists in placing 

 thein for a short time in fresher water than that from which they have been 

 taken. 



Persons who are fond of this animal as an article of food, know how much 

 the "fresh " exceed the "salts" ia size and consistency. Tbe " Morris Coves" 

 of this city [Philadelphia], while very insipid, are the plumpest bivalves brought 

 to market. On the other hand, the " Absecoms " and " Brigahtines," while of 

 a better flavor (to those who prefer salt oysters), are invariably lean compared 

 • to their transplanted rivals, as also are tbe ''Cape Mays," though, for some 

 reason, not to the same extent. 



The most experienced oyster-dealers inform me that the time for allowing 

 the salt oysters taken from the sea- coast to lie out varies, but is seldom over 

 two or three days. At the end of this time the maximum plumpness is attained, 

 and beyond this the oyster becomes lean again, besides having lost in flavor. 



The subjoined statements by Lieutenant J. A. Ryder are interest- 

 ing in this connection. They are taken from a letter to Professor 

 Baird, United States Commissioner of Fish and Fisheries, on " Floats 

 for the So-called Fattening of Oysters " : J 



The simplest and most practical structures of the kind which I have seen are 

 the storage and fattening floats used by Mr. Conger, of Franklin City, Maryland, 

 and now in use by all the shippers and planters in the vicinity of Chincoteague 

 Bay. I have been informed that similar structures, or rather structures serving 

 similar purposes, are in use on the oyster-beds along the shore of Staten Island, 

 New York. 



It is probably a fact that in all these contrivances they take advantage of the 

 effect produced by fresher water upon oysters which have been taken from 

 slightly Salter water. The planters of Chincoteague call this "plumping the 

 oysters for market." It does not mean that the oysters are augmented in vol- 

 ume by the addition of substantial matter, such as occurs during the actual 

 appropriation of food, but only that the vascular spaces and vessels in the ani- 

 mals are filled with a larger relative amount of water due to endosmose. It is a 

 dealer's trick to give bis produce a better appearance in the market, and as such 

 I do not think deserves encouragement, but rather exposure, 



* A detailed account is also to appear soon in the " Zeitschrift fiir Biologic." 

 f "Note on Dialysis in Oyster-Culture," in "Proceedings of Philadelphia Academy of 

 Sciences," 1875, p. 472, 



X "Bulletin of the United States Fish Commission," 1884, p. 302, 



