4 oz. weekly during the succeeding three months, it should when it is six months old weigh about 15 lb., and be ingesting about 35 or 36 oz. of milk daily. Having approximately determined the quantity of milk the breast-fed infant ingests in twenty-four hours, we may now attempt to solve the very vexed question as to how much milk at a feed the infant is capable of making use of, for on this hangs the very important question as to how many feeds the infant should have in the twenty-four hours. We are all fairly well agreed that in the interest of the mother, and for that matter of the child, too, nursing should be suspended entirely if possible between the hours of 10-11 p.m. and 5-6 a.m.

I would here, however, observe that mothers' milk, which at first is extremely rich in proteins and mineral substances, so rich in proteins that it coagulates on boiling, becomes as lactation progresses poorer and poorer in proteins and correlatively also in mineral ingredients, so poor that when the child is nine months old the protein. content of the milk is one-third less than it was in the early days of the infant. This well-known fact hardly supports the pronouncement made by experimental embryologists that, during the period of most rapid growth, growth is effected by the absorption of water more than the assimilation of foodstuffs. In choosing a wet nurse, however, for any infant, it is very evident that the child of the foster-mother should be as near as possible of the age of its foster-brother or sister.

Nature, it must be remembered, too, does not usually provide a supply of food for the infant until it is at least about thirty-six hours old, and in this connection it is worthy of note that among AmericanIndian tribes, people still living in a more or less primitive state, the mothers seldom put their infants to the breast earlier than thirty-six hours after birth, and in the case of some tribes-the Lipans, for example the mother is even forbidden to attempt giving suck to the infant until it is two days old. Fortified with such knowledge, mothers in this country should not too easily be discouraged nor too readily be induced to abandon the idea of nursing merely because the flow of milk does not appear to be established as early as they may have been led to believe it would.

After due deliberation and consideration, I have on anatomicophysiological grounds no hesitation in asserting that, leaving out of count the first two days after birth, the infant during the first six weeks should receive from 13 oz. to 2 oz. of milk at each feed, and should be fed during the day every two hours, and for this period

only, once during the night if necessary, that when six weeks old and until the end of the third month it should have 2 oz. of milk at each feed, and should be fed every two and a half hours, and that thereafter until it is weaned, at or about the ninth month, the feeds should gradually be increased to 5 oz., and the infant should be fed every three hours.1 As I have already stated, the protein content of mother's milk diminishes to a marked extent between the sixth and ninth months of lactation. If this fact be of any physiological importance, and this we can hardly doubt, then it is clear that the relative increase in the water content of the milk at or about this time must be of some very decided advantage to the child at this stage of its development and growth. Just what its true value and significance may be, and whether we should be justified in attempting to imitate this procedure of Nature when cow's milk is fed as a substitute for mother's milk, are still matters for investigation and settlement. For the time being, however, we may assume that Nature does not intend the quantity of the feeds to be materially increased between the sixth and ninth months, otherwise she would not have diminished the protein content of mother's milk.

The Duration of Suckling.

Just how long the infant should be suckled is another very debatable question, because we have no unimpeachable physiological data to guide us in the matter, and neither the customs of primitive peoples nor biblical history aid us in arriving at any definite conclusions thereon. Amongst primitive peoples we find that many mothers suckle for two, three, and even four years, whilst, according to II. Maccabees vii, 27, the Jewish child was in olden times invariably suckled for three years. That the child whenever possible should not be weaned before it is nine months old I have no misgivings, but whether nursing should, in the interest of the mother, or for that matter of the child, be prolonged much beyond that period I have the gravest doubt.

Artificial or hand feeding of the infant is occasionally, as everyone will readily recognize, unavoidable; but there is now, unfortunately, not only an increasing disinclination, but what is much more serious and disconcerting, a growing inability on the part of mothers to breast-feed their infants, consequently artificial feeding is, and has to

If a colt is running with its mother in the pasture it will nurse at least every two hours until it is about three months old.

be, much more frequently resorted to than was the case in bygone years. This disposition to the failure of such an important physiological function has begun to attract attention in other countries as well as our own. It can, unfortunately, only be viewed as an indication of degeneracy, and as yet no feasible explanation of its cause has been offered.

Mothers should clearly understand that science has not found, and probably never will be able to produce a foodstuff for the infant capable of being considered in all respects a perfect substitute for mother's milk. This being so, if the State is really and truly intent upon doing its utmost to preserve and adequately sustain infant life, then, because so much of it is sacrificed and imperilled through parental lack of knowledge of the biochemical requirements of the infant, it is the bounden duty of our Government to determine what is in the truest sense of the word the best substitute for mother's milk, and to settle definitely the many details connected with hand feeding, and not to shelve their responsibility by leaving such important matters to be dealt with according to individual whims and fancies.

Substitute Milks.

That the ideal substitute for mother's milk is the milk of some other animal there cannot be the least shadow of a doubt. In support of this contention we have but to adduce, not only the analytical facts to which we have already referred concerning the more important milks, but the still further very noteworthy fact that in the so-called whey or serum of milk there exist two proteins, lactalbumin and lactoglobulin, which in chemical constitution are almost identical with the two proteins, serum albumin and serum globulin, present in blood. It must be remembered, too, that there are in milk certain ferments which in the natural state aid and promote digestion. Moreover, from our knowledge of the relative digestibility of animal and vegetable foodstuffs it will readily be acknowledged that the co-efficient of digestibility of any combination of foodstuffs devised by man cannot possibly compare with the unusually high coefficient of digestibility of milk.

The milk selected, however, for the artificial feeding of the infant, whilst in chemical composition it should be as near as possible that of human milk, should be at the same time easily procurable. (See Table IV.) In this country the milk of the cow is that which fulfils these demands, but even it is not free from intrinsic and extraneous

TABLE IV.-INDICATING CONSTITUENTS IN ONE HUNDRED PARTS OF MILK.

drawbacks. A glance at Tables I and II will enable us readily to appreciate some of the disadvantages, for it will be observed that, whilst the amount of casein in cow's milk is double that in human milk, the mineral ingredients, on the other hand, are three times. greater. Now mineral substances play, as I have long maintained, an all-important part in the building up and energizing powers of the body, and it is on this account that the relative proportions of these inorganic elements in human and cow's milk (see Tables II and VI) are so markedly at variance, and this obtains, too, in the case of the milk of other animals, for in all cases Nature has determined and fixed these according to the requirements of the young of the different species. Although, however, the amounts of the mineral substances in human and cow's milk are so different, they nevertheless are in both cases the self-same mineral substances, and this is likewise true of all milks (see again Table II). Concerning the organic foodstuffsthe proteins, fat and sugar-in human and cow's milk these all resemble each other very closely, but as to the caseinogen-the chief protein-it will be observed from Table V that the sulphur content of human caseinogen is nearly double that of cow caseinogen.

TABLE V.-GIVING RESULTS OF ANALYSIS OF CASEINOGEN.

This, in my opinion, is a matter of very great importance, for I am convinced that our immunity or susceptibility to disease depends greatly upon the sulphur content of our bodies, and that it is largely on this account that the resisting powers in the artificially fed infant are so inferior to those in the infant that is nursed, for in no known way is it possible to so increase the sulphur content of any artificial food as to make it in this respect equal to human milk. The physical behaviour of the two caseinogens is, moreover, very different, for the clot or curd which forms in the stomach when human milk is fed is flocculent and easy of digestion, whilst that which results from cow's

milk is lumpy and more difficult of digestion. By diluting cow's milk, however, with water and adding milk sugar, we can so alter the physical characters of the clot or curd as to make this more like that of human milk, and render the caseinogen at the same time more easy of digestion.

The Homogenization of Milk.

Let me add a few words about the homogenization of milk. By this process, it is alleged, the various particles in the milk, more especially the fat and the casein, are reduced as nearly as possible to a uniform size. Homogenization is effected by means of a machine with a system of three pumps. These pumps force the milk through a small aperture against a hard surface, under a pressure of from 1,000 to 5,000 lb. to the square inch. It is stated that the curd formed from homogenized milk is tender and flocculent, and on this account homogenization is supposed to improve milk for infant feeding. As, however, cow's milk must be diluted and have added milk sugar, and as by this treatment we so modify the natural curd and render it more like the curd of human milk, homogenization is not a commendable practice. It means undue handling and tampering with the milk, and, in the interest of the infant, the less we handle and tamper with the milk which is to be fed to it the better altogether.

The Pasteurization of Milk.

Until quite recently fresh cow's milk was always abundantly available for the artificial feeding of infants, and for many years in framing our conclusions as to how this should be reduced and modified so as to make it as fit a substitute as possible for human milk, we have been guided more or less entirely by our intimate knowledge of the chemistry of cow's milk in the raw state. Milk, however, because of its composition and unique properties and qualities, is a most fertile medium for the development and growth of micro-organisms, and quite recently, partly with the object of killing these micro-organisms-especially those of a disease-producing character-and partly with the object of making milk keep sweet for a longer time than it naturally would there has sprung up the practice of "pasteurization," and so general has this practice unfortunately now become that it is to all intents and purposes impossible to obtain or procure in our towns and cities raw milk for the feeding of infants. This in my opinion is a most serious matter, and one calling for immediate Governmental attention and rectification, otherwise irreparable harm and danger may accrue to the