Fish becomes every year more and more popular as an article of food. It is abundant, and there are many inexpensive varieties. Moreover, it furnishes an excellent diet for those who work with their hands as well as their heads, and has the additional virtue of being easily digested by invalids.

There are three classes of fish:

1. Oily Fish, such as salmon, eels, herrings, and mackerel. The flesh of these fish is dark, because the oil is distributed throughout the flakes, and, although it is richer and more nutritious than the flesh of white fish, it is more difficult to digest.

2. White Fish, such as whiting, soles, cod, and plaice. The oil, or fat, in these fish is stored in the liver, with the result that the flesh is light, digestible, and particularly white in appearance. For invalids white fish should always be selected, never the oily kinds.

3. Shell Fish, such as oysters, crabs, lobsters, etc. These fish are popular, but, with the exception of the almost self-digesting oyster, are less wholesome than the two other classes, owing to the close texture of the flesh.

Fish must be fresh and well cooked. Stale or undercooked fish is not only unpleasant to eat, but also is positively dangerous.

Fresh-water fish must be cleaned at once, since, if left uncleaned for long, it will develop a muddy flavour, which is most disagreeable. Very speedy cooking, also, is important. Moreover, if the fish smells at all muddy, it should be washed, or even soaked.

White fish are best when fried; oily fish, when baked or grilled, since, if cooked in fat, they become even richer than before.

Since it lacks fat, and fat is essential for health, white fish should be eaten with a sauce composed of butter and milk, etc. Bread-and-butter and some starchy food, such as potatoes, should always be eaten with fish to render the meal of greater dietary value.

How to select fish When selecting fish in a shop, it is important to observe that:

1. The eyes are full and bright.

2. The gills are a clear, bright red.

3. The body is stiff.

4. The flesh is firm and elastic to the touch.

5. The smell is fresh, not unpleasant.

6. Girth is large in comparison to length. Very large fish should be avoided, since it is probable that they are old and that the fibres are stringy.

special hints for special fish Salmon: The head and tail should be small; shoulders, thick; scales, clear and silvery; and the flesh a bright, yellowish red. Cod: The head should be large; tail, small; shoulders, thick; liver, creamy white; and the skin clear and silvery, with a bronze-like sheen.

Mackerel: The markings on skin should be very bright and distinct, and the underside should be a creamy white.

Plaice: The body should be thick, the spots on skin bright orange, and the skin itself unwrinkled. The white side, moreover, should be of a pinkish, not a bluish tint.

Soles, Brill, and Turbot: The body should be thick, the skin bright and un-wrinkled, and the under-side a creamy white.

Eels are best bought alive, and should be from 1 1/2 lb. to 2 lb. in weight, and silvery in appearance.

Smelts should have a faint smell resembling that of a newly-cut cucumber.

Lobsters, Crabs, Shrimps, and Prawns. The tails, when pulled out straight and then loosened, should spring back and clip tightly against the body. Lobsters with incrustations on the shell are usually old and tough.

Oysters. The shells must be tightly closed, and preference commonly is given to the small kinds with fairly smooth shells.