This section is from the book "Economical Cookery", by Marion Harris Neil. Also available from Amazon: Economical Cookery (1918).
"'Tis very fresh and sweet, sir, The fish was taken but this night."
Fish may be divided into three classes - white, oily, and shell fish. The first two, "white" and "oily", may be served in the place of meat for breakfast or luncheon, and in a dinner of several courses follow the soup.
"White" fish is not so nourishing as the "oily", as in the former class nearly all the oil is contained in the liver, but fish belonging to this class are more easily digested, and therefore more suitable for invalids. Oily fish, as salmon, mackerel, etc., are very nourishing but not suitable for people with weak digestions. All fish must be perfectly fresh, as the flesh decomposes very rapidly, giving rise to danger of poisoning and even death. When choosing fish see that the eyes are bright and prominent, the gills red, the flesh firm, and the smell good. If the fish is decomposing, the bones on being removed leave a red mark, and the flesh on the underside, if strongly pressed between the thumb and finger, will easily crush, leaving only the skin in the fingers. Bloodshot eyes show the fish is either stale or out of condition. Fish may be boiled, baked, steamed, stewed, fried, grilled, or planked. Almost the same rules apply to the cooking of fish as to that of meat, namely: To keep in the juices, to develop the flavor, and to make the dish pleasing to the eye and appetite.
Fish is most useful in the dietary of the convalescent, or those leading sedentary lives, who suffer from indigestion.