Fish is richer in flesh-forming elements than game, poultry, lamb or veal, but it contains less fat and gelatin. It is easily digested, and makes strong muscular flesh, but does not greatly increase the quantity of fat in the body. The red blooded and oily kinds, such as salmon, sturgeon, eels and herring, are much more nutritious than the white blooded varieties, such as cod, haddock, and flounders. The salting of rich, oily fish like herring, mackerel, salmon, and sturgeon, does not deprive it of its nutritive elements to the extent that is noticeable with cod; salt cod fish is almost entirely devoid of nutriment, while the first named oily varieties are valuable adjuncts to a vegetable diet.

Although fish contains more water and less solid nutriment than meat, it is generally useful from its abundance and cheapness; and certain kinds which are called red-blooded, are nearly as nourishing as meat: oily fish satisfies hunger as completely as meat; herring, especially, makes the people who eat it largely strong and sinewy. Sea fish are more nourishing than fresh water varieties.

Sea fish, and those which live in both salt and fresh water, such as salmon, shad, and smelts, are the finest flavored; the muddy taste of some fresh water species can be overcome by soaking them in cold water and salt for two hours or more before cooking; all kinds are best just before spawning, the flesh becoming poor and watery after that period. Fresh fish have firm flesh, rigid fins, bright, clear eyes, and ruddy gills.

Oysters, clams, scallops, and mussels, should be eaten very fresh, as they soon lose their flavor after being removed from the shell.

Lobsters and crabs should be chosen by their brightness of color, lively movement, and great weight in proportion to their size; you ought always to buy them alive, and put them head first into a large pot of boiling water, containing a handful of salt; they will cook in about twenty minutes.