The purpose is not to give such recipes as are found in ordinary cookbooks, but simply to suggest foods useful for invalids, for semi-invalids, or for chronic, abnormal conditions of digestive organs.

Water. Pure and carbonated; mineral waters containing iron, sulphur, lithium, etc.

Hot drinks should be served at a temperature of from 122 to 140 degrees F. When water is used as a hot drink it should be freshly drawn, brought to a boil, and used at once. This sterilizes and develops a better flavor.

Cold water should be thoroughly cooled, but not iced, unless ice water is sipped very slowly and held in the mouth until the chill is off. Water is best cooled by placing the receptacle on ice rather than by putting ice in the water.

Fruit Juices. Under fruit juices are: grape juice, apple juice, currant juice, pineapple juice, orangeade, and lemonade.

They are especially grateful to fever patients and are often used to stimulate the appetite. They are particularly valuable for the acids which they contain, which aid the action of the kidneys and the peristaltic action of the digestive tract; they also increase the alkalinity of the blood.

Apples contain malic acid, lemons citric acid, and grapes tartaric acid. The ferment in the ripe pineapple juice aids in the digestion of proteins.[16]

Lemonade. Wash and wipe a lemon. Cut a slice from the middle into two pieces to be used in the garnish before serving; then squeeze the juice of the rest of the lemon into a bowl, keeping back the seeds. Add sugar and boiling water; cover and put on ice to cool; strain and pour into a glass.

Fruit Lemonade. To change and vary the flavor, fresh fruit of all kinds may be added to strong lemonade, using boiling water as directed above.

Egg Lemonade. Beat an egg thoroughly, add 2 tablespoonfuls of sugar, 2 tablespoonfuls of lemon juice, and gradually pour in one cup of cold water. Stir until smooth and well mixed. Serve thoroughly cold. This drink is very easily digested, the lemon having partly digested the egg; 2 tablespoonfuls of sherry or port may be added.