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Page:Popular Science Monthly Volume 32.djvu/89

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79
THE CHEMISTRY OF "OYSTER-FATTENING."

States Fish Commission, and which included examinations of a number of specimens 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 detail in one of the publications of the Commission,[1] in which the principles involved and some side-issues of the experiments will be discussed. 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[2] are by Professor Persifor Frazer, Jr., who attributes the changes mentioned to dialytic action:

The oysters brought to our large markets on the Atlantic seaboard are generally first subjected to a process of "laying out," which consists in placing them 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" in size and consistency. The "Morris Coves" of this city [Philadelphia], while very insipid, are the plumpest bivalves brought to market. On the other hand, the "Absecoms" and "Brigantines," while of a better flavor (to those who prefer salt oysters), are invariably lean compared to their transplanted rivals, as also are the "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 interesting 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":[3]

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 volume 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 animals are filled with a larger relative amount of water due to endosmose. It is a dealer's trick to give his produce a better appearance in the market, and as such I do not think deserves encouragement, but rather exposure.

  1. A detailed account is also to appear soon in the "Zeitschrift für Biologie."
  2. "Note on Dialysis in Oyster-Culture," in "Proceedings of Philadelphia Academy of Sciences," 1875, p. 472.
  3. "Bulletin of the United States Fish Commission," 1884, p. 302.