Prescription blanks are furnished the physician, who fills out the percentages of fat, milk-sugar, proteids, and alkalinity, to suit the age, weight, and general condition of the child.  He orders also the amount to be given at each feeding, and the number of feedings to be given in the twenty-four hours.  Each bottle contains just the amount to be given at one feeding.  All that the mother needs to do is to place the bottle in a receptacle containing warm water, until the milk has attained a temperature of 99° F., remove the cotton stopper, and put on the nipple, when it is ready for use.

The Nursing Bottle.—­ This should be of clear glass, with a rounded bottom, and of such a shape as is easy to clean; so that no particles will cling around a corner which cannot be reached.  The graduated bottle is the most convenient, as it enables the quantities of each of the materials used in the preparation of the feeding to be mixed in the bottle, doing away with the trouble of measuring before putting into the bottle.

Rubber Nipples.—­ Two nipples should be kept for alternate use, and no nipple should be used longer than two weeks.  A soft rubber of conical shape is best, with an opening at the top which is not too large, so that the milk will not flow through, as it is desirable that the child should obtain the milk by suction.  So soon as the feeding is over, the nipple should be removed from the bottle, and brushed on both sides with a stiff brush.  It should then be put in cold water, where it is kept until it is again wanted.

The baby should be fed slowly, from ten to twenty minutes being taken for each feeding.  Sucking from an empty bottle or with a nipple in the mouth should never be permitted, as in this way the baby draws air into its stomach, which will result in colic.  Each flask should contain only enough for one feeding.

In lieu of the regular sterilizing apparatus, milk may be similarly prepared by placing the milk in an ordinary glass fruit-jar with a screw lid.  This is placed in a colander over a pot of boiling water; the milk should be allowed to boil in the open jar for two minutes; the jar-lid is then screwed on, and it should steam for twenty minutes longer.

The capacity of the infant stomach at birth is about one ounce, which is the average quantity of food that should be taken at one meal.  The average rate of increase in the amount of food is one and a half drams a week for the first six months; subsequently somewhat less.  The intervals of feeding should be two hours at birth, and increased to three hours at the end of the third month.  The food should be given at a temperature of 99° F. and fed directly from the sterilizing bottle.

Fresh Air.—­ In warm weather the baby is taken out-of-doors in from three to four weeks after birth; in cold weather not before two to three months.  In the latter case it is prepared for the change by being first dressed as for the street, with wrap and cap; the windows of the room are then opened, and the infant is carried about here.  In the winter months when the baby is first taken out, it is better to carry it in the arms, as it will be kept warmer in this way, and if it does become chilled it will be more quickly noticed.