The palm has been awarded to oysters at our tables as a most exquisite dish. Oysters love fresh water and spots where numerous rivers discharge themselves into the sea. Generally speaking, they increase in size with the increase of the moon, but it is at the beginning of summer, more particularly, and when the rays of the sun penetrate the shallow waters, that they are swollen with an abundance of milk.[158]

Oysters are of various colors; in Spain they are red, in Illyricum of a tawny hue, and at Circeii black, both in meat and shell. But in every country, those oysters are the most highly esteemed that are compact without being slimy from their secretions, and are remarkable more for their thickness than their breadth. They should never be taken in either muddy or sandy spots, but from a firm, hard bottom; the meat should be compressed, and not of a fleshy consistence; and the oyster should be free from fringed edges, and lying wholly in the cavity of the shell. Persons of experience in these matters add another characteristic; a fine purple thread, they say, should run round the margins of the beard, this being looked upon as a sign of superior quality, and obtaining for them their name of “calliblephara.”[159]

Oysters are all the better for travelling and being removed to new waters; thus, for example, the oysters of Brundisium, it is thought, when fed in the waters of Avernus, both retain their own native juices and acquire the flavor of those of Lake Lucrinus. Mucianus, who is really a connoisseur, says:—“The oysters of Cyzicus are larger than those of Lake Lucrinus, fresher than those of the British coasts,[160] sweeter than those of MedulÆ, more tasty than those of Ephesus, more plump than those of Lucas, less slimy than those of Coryphas, more delicate than those of Istria, and whiter than those of Circeii.” For all this, however, it is a fact well ascertained that there are no oysters fresher or more delicate than those of Circeii, last mentioned.

According to the historians of the expedition of Alexander, there were oysters found in the Indian Sea a foot in diameter:[161] among ourselves, too, the nomenclature of some spendthrift and gourmand has found for certain oysters the name of “tridacna,”[162] wishing it to be understood thereby, that they are so large as to require three bites in eating them. We will take the present opportunity of stating all the medicinal properties that are attributed to oysters. They are singularly refreshing[163] to the stomach, and tend to restore the appetite. Luxury, too, has imparted to them an additional coolness by burying them in snow, thus making a medley of the produce of the tops of mountains and the bottom of the sea. Calcined oyster-shells, mixed with honey, are good sprinkled upon burns, and are highly esteemed as a dentifrice.