The nitrogenous matter in oysters is fourteen parts, of fatty matter one and a half, of saline matter two, and of water eighty.

At the time of spawning--from May to September--they lose their good condition, and become unwholesome.

_Lobsters_ rank next in importance, and are more delicate and finer-flavored than _Crabs_.

Both are, however, very difficult of digestion, and should only be used occasionally.

The many forms of pickled and smoked fish are convenient, but always less wholesome than fresh.
MILK comes next, and has already been considered in a previous chapter.