The Book of Household Management by Mrs. Beeton

218. THE GENERAL USE OF FISH, as an article of human food among

civilized nations, we have thus sufficiently shown, and will conclude this portion of our subject with the following hints, which ought to be remembered by all those who are fond of occasionally varying their dietary with a piscine dish:-- I. Fish shortly before they spawn are, in general, best in condition. When the spawning is just over, they are out of season, and unfit for human food. II. When fish is out of season, it has a transparent, bluish tinge, however much it may be boiled; when it is in season, its muscles are firm, and boil white and curdy. III. As food for invalids, white fish, such as the ling, cod, haddock, coal-fish, and whiting, are the best; flat fish, as soles, skate, turbot, and flounders, are also good. IV. Salmon, mackerel, herrings, and trout soon spoil or decompose after they are killed; therefore, to be in perfection, they should be prepared for the table on the day they are caught. With flat fish, this is not of such consequence, as they will keep longer. The turbot, for example, is improved by being kept a day or two. GENERAL DIRECTIONS FOR DRESSING FISH.