One method of testing the freshness of eggs is to drop them into a strong, salt brine made by adding two ounces of salt to a pint of water. A fresh egg will at once sink to the bottom. If the egg is three days old the surface of the shell will be even with the surface of the water and an egg two weeks old will float mostly above the surface. The opinion is prevalent that a hard-boiled egg is difficult of digestion, but this depends entirely on the mastication. If it is masticated so that it is a pulp before being swallowed, a hard-boiled egg is readily digested. A soft-boiled egg should not be boiled longer than three or four minutes, or better, should be put into warm water, be allowed to come to a boil, then set off the fire and the egg be allowed to remain in the water for ten minutes. This method cooks the egg through more evenly. Another method of cooking the yolk evenly with the white is to put the egg in cold water, let the water come to a boil, and again immerse the egg in cold water. The immersing in cold water after boiling makes hard-boiled eggs peel readily. _CARBO-NITROGENOUS FOODS_ Under this class come cereals, legumes, nuts, milk, and milk products. In these foods the nitrogenous and carbonaceous elements are more evenly proportioned than in either the carbonaceous or nitrogenous groups. The different food elements in this group are so evenly divided that one could live for a considerable length of time on any one food. Some animals build flesh from nuts alone, while the herbivorous animals live on cereals and plants. * * * * * [Sidenote: Cereals] Under cereals, used by man for food, come wheat, oats, rye, barley, rice, and corn. As will be noted by Table V, cereals contain a large proportion of starch and are therefore used largely for heat and energy. Rice contains the largest proportion and next to rice, wheat flour. TABLE V CEREALS