The uses of some of these substances are not thoroughly understood, but if deprived of them, the nutrition of the body suffers. Lime (calcium) is necessary for the bones and teeth and to preserve the coagulability of the blood. Sodium chlorid (common salt) aids the formation of hydrochloric acid and the activity of the pancreatic juice. The salts of iron are necessary for the blood. Other salts are also needed to carry on the chemical reactions in the digestive system. Cereals, all vegetables, fruits, and nuts furnish both calcium salts and sodium, potassium, and magnesium, which are the salts in the blood and lymph. Minerals are also abundant in dried legumes (beans and peas). Fruits and nuts contain the least amount of these salts, and meats, vegetables, and cereals follow in the order named, cereals, that is the whole of the grain—not the white flour—containing the most. Any diet, therefore, which recommends the use of fruits and nuts to the exclusion of other foods, depletes the system of some of the body-building elements. The system may seem to thrive for a time on such food because, perhaps, of the rest given to overworked organs, but eventually the body lack will manifest itself; anemia may appear or malnutrition become evident. Milk furnishes salts in proper proportion for building the bones and teeth of the baby; because of the lime which it contains it is a good food for the growing child. After the child is one year old, eggs may be added to the diet. During the first year the albumin and fats in the egg are not well digested. It is especially essential that children be furnished milk and eggs that they may be assured of the proper proportion and quantity of calcium salts for growth. Sodium chlorid (common salt) has been for ages recognized as an important element in food, so important that in Eastern countries it is the symbol of hospitality and friendship. When taken in moderate quantities, salt increases the activity of the gastric secretion and aids the appetite. When taken in excess, as many who have formed the salt-eating habit do, it is an irritant to the mucous membrane of the stomach and intestines and may interfere with nutrition, causing dyspepsia, gastroenteritis or diarrhea from the continued irritation. The habit indulged by some of nibbling at salted nuts of various kinds, at and between meals, may for a short time satisfy the needs of the body for more salt than is usually taken with the food, but such a habit persisted in will cause acidity of the stomach from overstimulation of the hydrochloric acid producing glands; it will also decrease the fluidity of the blood by causing the water to be drawn from the blood for the use of the tissues. Irritative action is also exerted on the kidney, as any excess of salt is excreted by this organ. For this reason salt is often prohibited for those suffering from any inflammation of the kidney, in Bright’s disease, etc.