Many attempts have been made to produce meat preparations which shall be not only pleasing to the taste, but also nourishing. One of the earliest of these preparations put upon the market was Liebig's Extract of Beef. In more recent times such other preparations as Armour's Extract of Beef, Valentine's Meat Juice, and Wyeth's Meat Juice have been put upon the market. While these preparations contain practically no nourishment, the total proteid matter available for nourishment being, as a rule, about one half of one per cent, still the flavor of these extracts and juices is very pleasing, due to the creatin and related bodies among the extractives, and they may be used in broths, bouillons, and soups to give a meat flavor. Bouillon may be directly prepared from meat by cutting it into small bits or grinding it in a meat grinder, heating slowly for a moderate time, then boiling vigorously for a short time. In this preparation the flavoring materials have been extracted, but the nutrient proteins have been coagulated by the heat and do not appear in the clear bouillon, which has an agreeable appetizing flavor, but represents absolutely no nourishment. Because of its flavor it incites the flow of digestive secretions. Bouillon may be used as a valuable vehicle for cereals, vegetables, and eggs, in soups.

Meat juices, such as Murdoch's Liquid Food, Johnston's Fluid Beef, and Bovinine, contain from nine per cent to fourteen per cent of available protein, and are probably the best preparations of this character.

Meat jellies may be prepared in the home by taking any meat in which there is a large proportion of connective tissue. Put it into cold water in a pot and bring it very slowly to the boiling point, and allow it to simmer for many hours. This slow cooking of the connective tissue gelatinizes it; after it cools, the gelatin may be separated from the fat, bones, and lean meat, and remelted and cooled. This homemade meat jelly usually possesses the pleasing flavors given it by creatin, and is a pleasing addition to the diet of an invalid. However, it must not be forgotten that gelatin cannot take the place of proteins for growth and repair. It is used in the body practically the same as the carbohydrates and fat - that is, it is a fuel food and not a tissue builder. It differs from the other fuel foods in this, that the waste materials resulting from its oxidation are similar to the waste materials resulting from the oxidation of protein, and must therefore be eliminated by way of the kidneys.

Fish is an important source of protein foods, the flesh of fish being, as a rule, delicate and tender, and possessed of a flavor common to practically all fish, but very different from that of the meat of mammals and birds. In order to develop the flavors of the fish and to insure the killing of any parasites present, it should be thoroughly cooked. The usual methods of cooking fish are frying, baking, broiling, boiling. The flavors are perhaps most highly developed by the first of these methods named. The readiness with which the flesh of fish undergoes decomposition changes makes it necessary either to use this food fresh from the water or subject it to some preserving process, either refrigeration, salting, drying, smoking, or canning.

The sea foods most commonly used may be divided into two groups, crustaceans and mollusks. The crustaceans are the lobster, crab, and shrimp. These animals are greenish in color when alive, but on boiling turn bright red. The skeleton of a crustacean is external. It is the skeleton which turns red on boiling. When the exo-skeleton or crust is broken after boiling, the sweet, tender muscle can be readily removed, but while the meat of the crustacean possesses a delicate and pleasing flavor, it is not easily digestible, and for some people seems to be quite indigestible. Lobster and shrimp are largely used in salads, while a common method of serving crab meat is to grind it in a hasher, mix with condiments, and serve in the empty shells as "deviled" crab.

The mollusks usually used as foods are oysters, clams, and mussels. As stated above, it is the whole body of the animal that is eaten, including the muscular system, digestive system, gills, and connective tissue. The soft body of the mollusks is occupied very largely by stomach and liver, though as the spawning season approaches the oyster contains a considerable amount of a milky solution which contains the spawn. During the spawning season

Table IV. - Animal Foods

(May to September) oysters are not considered edible. Furthermore, they should be protected during this season from the fishermen, as the supply of oysters is becoming somewhat exhausted. While oysters may be eaten raw, and in this condition are an easily digestible food, one is in some danger of infection.