In the feeding of infants with milk modifications, what amounts and what proportions of the mineral elements should be in the formula? As in many other respects in infant nutrition, empiricism has striven to imitate nature by making the salt content of milk modifications approximate that of human milk. Although no formula superior to breast milk has been devised for the average baby, it does not follow that breast milk contains the ideal composition of salts for sick babies or for normal babies at all times.
It is well known that in the present civilization, infants nourished at the breast are subject to such defects in mineral metabolism as are expressed in rickets and tetany. Premature infants are especially subject to rickets, and practically all infants develop this condition, whether breast feeding or milk modifications are employed. The concentration of salts in cow's milk is about three times that of