plishing this end, all of them depending upon the fact that a temperature equalling that of boiling water, or even less, if applied sufficiently long, will prevent souring. The milk mixture may be boiled in a vessel immediately before using, or it may be placed in bottles and these. surrounded by boiling water or steamed in a farina kettle. The objections to actually boiling the milk are that it gives it an unpleasant taste, produces a tough scum on it, and affects its chemical character in such a way that it becomes less digestible and more constipating than before. The other methods are crude and not very satisfactory. It is far better, therefore, to procure at once the apparatus known as a sterilizer, since its initial cost is small and it will save a world of trouble in the end. It should be almost as much of a necessity in the household as are the baby's clothes.

The great principle of all sterilizing is, first, the killing of germs present in the milk, and, second, the preventing of other germs from entering into it later. If both these ends are fully met, the milk will keep sweet for months or even years. Such perfect preparation is, however, seldom attained and is not necessary. Various forms of sterilizers have been devised, but one of the best is that known as Arnold's. This apparatus is provided with eight bottles each holding a little over seven ounces, and marked on the glass with a graduated scale of ounces, by means of which the amount of nourishment poured into them can readily be measured (Fig. 34).

The method, then, in detail for preparing the baby's food is as follows: As soon as the milk and cream come in the morning, the mixture for the entire day should be prepared according to the formula on page 130. As large a quantity should be made as the table on page 122 or the experience with the individual child shows will be required

The bottles, previously thor

for the twenty-four hours. oughly cleaned with a bristle brush and dried, should each be filled with as much of the mixture as is required for each

feeding. They must next have their mouths carefully dried and stopped with plugs of ordinary raw cotton. They are then placed in the rack in the sterilizing cham

ber and the lid and hood are applied. The pan of the sterilizer is now filled two-thirds full with water, and the whole is placed on the hot stove for an hour. About twenty minutes of this time will be occupied in heating the milk up to the proper temperature, and the remainder in keeping it at that point and thus sterilizing it. Raw cotton is used as a plug because experience shows that the most minute germs cannot pass through it. It is necessary, however, that it shall not come into contact with the milk.

When it is desired to carry the bottles about to any extent after sterilizing, it is better to use a rubber cork instead of the cotton. In this case the bottles, with the corks very loosely in place, are put in the sterilizer for about twenty minutes until the liquid and the air contained is thoroughly heated. The corks are then pushed firmly into place and the sterilizing is continued. The bottles thus corked may lie afterward in any position.

Sterilized milk prepared in this way should keep perfectly sweet without being placed on ice. As an additional safeguard, however, it is better to keep the bottles in a cool place, although this is not needed if the process has been properly carried out. We must never forget that the cotton plug must not be removed, even for a moment, from the time it is first put in place until the time for feeding the baby comes.

Food prepared as described above will keep perfectly well for twenty-four hours at least, but in the hottest weather it is an additional safeguard to re-heat in the evening the bottles which are to be used during the night and early morning.

When milk is to be prepared for use while travelling, a more thorough sterilization is necessary in order to avoid the possibility of any germs being left

alive. To accomplish this the bottles should be subjected to sterilization upon one day, again upon the second, and then again upon the third. It is more convenient in such cases to use large bottles to carry the mixture, and to pour out of these the amount needed, since carrying so many small ones may be impracticable. We must remember, however, that as soon as the large bottle has once been uncorked germs will enter it, and the milk is liable to spoil rapidly unless kept on ice and soon used.

The disadvantage of using lime-water in preparing the milk mixture becomes evident in sterilizing. Not only does the lime combine in some way with the sugar and produce a brownish color, but it is largely precipitated by boiling, and the lime-water is thus destroyed. We can, of course, obviate this by adding the lime-water to each bottle just before feeding the baby, but it becomes rather a complicated matter to calculate just what quantity of it is required with the gradually increasing amounts of nourishment which the baby demands. The use of sodasolution instead of lime-water allows us to complete the mixture at the outset.

As already stated, it seems certain that the boiling of milk, or even the sterilizing of it in the manner described, lessens its digestibility to some extent. Any disadvantage of this kind is, however, usually more than made up by the advantage accruing from the killing of the germs. Still, if the milk is found to disagree, we must use some other method of procedure to avoid the chemical changes. A modification of sterilizing, called Pasteurizing, has been proposed for the purpose. This process, named after the celebrated French scientist, Pasteur, consists in subjecting the milk to a temperature of about 167° Fahrenheit for half an hour, instead of to that of about 212° which sterilizing employs, and in then

removing it to the refrigerator just as soon as the bottles will stand the cold. It is claimed that this process destroys the germs sufficiently for practical purposes, and does not alter the digestibility of the milk.

Apparatuses for Pasteurizing have been devised, in which the milk is heated to the proper temperature by immersing it, in bottles, in a definite amount of boiling water which has just been removed from the fire. As the water cools the milk becomes warm, until it reaches at last 167° F.

Pasteurizing is not a very safe process, for, although it does not make the milk less digestible, it does not with certainty kill the germs. A better plan, where sterilized milk does not agree, is to use a modified Pasteurizing with the sterilizer. The bottles are filled and the apparatus is made ready as usual, but the hood is left off and the lid set ajar, and the heating is continued for only forty-five minutes over a brisk fire. In this way the temperature of the milk is raised only to about 185° or 190° F., instead of to 212°, as with ordinary sterilizing. This process does not materially alter the digestibility of the milk, but does ensure its keeping sweet in bottles for twenty-four hours, even though not put on ice.

A few words must be said about the articles required for feeding the baby with the artificially-prepared food, and the method of doing this. It is usually unnecessary to have any special nursing-bottle, for the ordinary sterilizing-bottle answers for nursing as well. When the time for giving nourishment comes the sterilizing-bottle containing the prepared milk should have the cotton plug. removed and be fitted with a rubber nipple and then be set in a cup of hot water until its contents are at a temperature not exceeding 95° to 100°. When, however, the baby wakes, hungry and impatient, at the time of its