CONSTITUENTS OF MOTHER'S MILK
Mother's milk—that wonderfully adaptable, ever-changing food, so accurately and scientifically suited to the hourly and daily needs of the growing child—is composed of five different parts, totally unlike in every particular, and each part exactly suited to the needs which it supplies. The cream of the milk, as well as the lactose or sugar, builds up the fatty tissues of the body as well as helps provide the energy for crying, nursing, kicking, etc. The proteins (the curd of the milk) are exceedingly important; they are especially devoted to building up the cells and tissues of the body of the growing child. The salts form a very small part of the baby's food, but an important one, for they are needed chiefly for the bones and the blood. The fats, sugars, proteins, and salts, taken together, form the solids of mother's milk, and are held in solution in the proportion of thirteen parts of solids to eighty-seven parts of water; which so holds these solids in solution that the baby can digest and assimilate these necessary food elements. The mother's milk increases in strength day by day and month by month as the baby grows, and is the only perfect infant food on earth.