Some common forms. Some sources. Albumen Eggs Casein Milk Myosin, fibrin, and elastin Meat Gluten Wheat Tuberin Potato Legumin Peas and beans Excelsin Brazil nuts Zein Corn _Milk_ contains a small amount of protein. In a glass of about 12 tablespoons of milk there is less than 1 tablespoon of protein. _Egg_ contains nearly as much protein as lean meat. =Value of Fruit and Vegetables.=—Vegetables contain protein, starch, sugar, cellulose, mineral matter, water, and undetermined substances. Fruits contain (chiefly) sugar, cellulose, mineral matter, and water. _Water_ removes wastes, lubricates tissues, aids in forming secretions, helps to equalize the temperature. _Acids_ help to maintain the alkalinity of the blood—stimulate the appetite. _Mineral salts_— Build bone. Help to make blood alkaline. Aid in digestion. Aid in excretion. Build red blood-cells. Build nerve tissue. Build cells. _Cellulose_ exercises muscular lining of digestive tract. _Note._—Good authority makes the statement that the housekeeper is wise who pays as much for milk, vegetables, and fruit as for meat, eggs, and fish. =Use of Eggs.=—Eggs serve as a meat substitute. Eggs require the addition of carbohydrates and some fruit or vegetables to form a well-planned meal. =Digestibility of Eggs.=—Raw eggs are more easily digested when beaten. They are often prescribed when a nutritious, highly concentrated diet is desired, and in cases of tuberculosis, some forms of anemia, and various wasting diseases. _Effect of Heat._—Egg albumen begins to coagulate at 134° F. and becomes jelly-like at 160° F. =Preservation of Eggs.=—1. _Water-glass (Sodium Silicate)._—Nine quarts of boiled water (cooled) to 1 quart of water-glass. Eggs will keep in this solution three and a half months. _Note._—A good grade of water-glass should be of the consistency of molasses. If heavier than this the water-glass should be diluted to the right consistency, as the eggs should sink. Eggs may be added to the solution from day to day as gathered. Do not wash. If the nests are clean the eggs will not need washing. Keep in a stone jar in a cool place just above the freezing-point. Do not use the solution the second year. The water-glass may be obtained in the dry or liquid form, and dissolved in either hard or soft water. 2. _Lime Solution._—Piece of lime size of lemon. Pour 1 gallon of boiling water over it. Let stand until cold. Add 1½ cups of salt. 3. _Paper Wrapping._—Wrap perfectly fresh eggs in paper and keep in cool place. This is not as effective as Methods 1 and 2, but keeps eggs for a short time. THE PREPARATION OF FOODS FOR THE SICK. TO PEPTONIZE MILK.