cally no actual work; while if she were actively employed and
doing a certain amount of physical labor, her rations would have to
approximate those of a man doing heavy muscular work (about 3,500 to
4,000 calories per day).[66]

~Breast Milk versus Cow's Milk.~--Consensus of opinion shows that
breast-fed infants require less energy than the ones who must be
nourished artificially. This is probably due largely to the fact that
the constituents of human milk are in a more available form than those
in cow's milk, the former requiring a lesser expenditure of energy on
the part of the organism to become available than the latter. Very
active babies, ones who kick and throw themselves about or cry
violently, have a greater energy requirement than the more placid baby
who sleeps more and is more quiet in movement and who cries less when
awake. Breast-fed babies are generally more quiet than their less
fortunate artificially fed brothers. It has been demonstrated that the
artificially fed baby has a much harder fight for existence than the
baby who receives his natural food; hence the necessity of using every
available means to make the food digestible, and to lessen the danger
arising from the additional work put upon the entire apparatus. Cow's
milk contains practically the same chemical elements as are found in
human milk, but these elements are combined in a slightly different
manner, and are not so easily handled by the immature organs. The
proteins of milk consist of casein, which is insoluble, and albumen,
which is soluble. According to Van Slyke the proportion of insoluble
to soluble protein in cow's milk is 3.6:1, while in human milk the
proportion is only 1:1. The ash constituents in cow's milk are in
excess of the needs of the infant organism, but since a great part of
these salts is in an inorganic form they are not retained to the same
extent as those contained in human milk, which are in an organic form.

~Rules and Regulations.~--It is not possible to lay down hard and fast
laws to cover the subject of infant feeding. The food must be adapted
to the individual needs of the baby in question. The nurse must see
that the milk is obtained from a responsible dealer, certified milk
being of course the safest. The bottles of milk should be wiped off
carefully and placed directly on the ice as soon as they are received.
The milk generally used in infant feeding has a fat content of 4%.
That having a higher percentage of