3. What changes are effected in the proper cookery of cereals? 4. What are the important points in practice? 5. What are the advantages of a good “ready to serve” breakfast cereal? 6. Ascertain the cost of a box of puffed cereal and an uncooked cereal of the same size. Weigh the contents of the two. 7. Estimate the cost of each one served to a family of six. 8. What is the cost of a 100-Calorie portion? 9. What is the advantage of serving dry toast with a cereal? CHAPTER IX EGGS, MILK, AND CHEESE Eggs are a specially interesting food because they contain all the elements necessary to the development of the young chick within the shell. The structure of the egg is familiar, with its division into the yolk and white, and it is interesting to note the details of this structure. Break a fresh egg carefully into a saucer. The shell is porous, allowing water to evaporate from the egg and air to enter. To this porosity is due the fact that other substances may enter the egg, giving it an unnatural flavor and even hastening its deterioration. Within the shell is a fine membrane which protects the white. The yolk is also divided from the white by a more delicate membrane which enables one to separate the yolk from the white of a fresh egg. A careful examination reveals at each end of the yolk a continuation of this membrane in the form of small cords which are fastened at each end of the shell, holding the yolk evenly suspended in the center of the shell. Rough handling or jolting breaks this membrane, and the yolk drops to one side. Lift the white carefully with a fork, and notice its elasticity. This cohesive property makes it possible to beat air into the white until the whole mass become porous. The yolk is creamy rather than light when beaten, and a bit of the yolk mixed with the white prevents the latter from becoming light and dry. =Composition of the egg.=——Figure 40 gives the composition of the yolk and white taken together, and of the yolk and white separated. The protein content is high, and the fat content as well, the yolk containing a higher percentage of these two foodstuffs than the white. The mineral matter is of high value, iron and phosphorus being found in ideal forms in the yolk. In using the egg as food we are availing ourselves of one of nature’s richest storehouses. A single egg of average size yields about 75 calories, of which 60 come from the yolk and 15 from the white. A _very_ large egg, weighing two and two thirds ounces, will yield 100 calories. [Illustration: FIG. 40.——Composition of eggs and cheese.]