We had discussed the qualities and sterilisation of cows' milk, and the value of observation and weighing in the regulation of an infant's diet, and I was demonstrating to you that the balance was indispensable as a guide in mixed feeding. I now wish to cite a few more cases which emphasise this important point.
A woman named Lud_____ was delivered in the Maternité on March 15, 1896. She was in feeble health, and during a previous lactation I had had considerable anxiety on her account. She was very eager to suckle, and, although she had not much milk, I allowed her to do so. The infant weighed 3050 grams at birth. As on March 28 he was only 2950 grams, I added 200 grams of sterilised milk to his daily ration (Fig. 92). On April 11 he reached 3420 grams, but, owing to the strain on the mother, I increased his cows' milk to 250 grams. His curve soon regained the normal. On May 31 his allowance was raised to 375 grams. On July 25 I learned from the mother that during the last few days her milk supply had greatly diminished. The hungry child had cried incessantly, and she, not wishing to inconvenience me by coming on any but the day set apart for the Consultation, had given the child some milk, previously boiled, in addition to what I had prescribed. I raised the 375 grams to 600, and the curve continued to rise steadily until November 21, when the infant was found to have lost 160 grams within a fortnight. As, in the absence of all pathological phenomena, this loss could arise only from underfeeding, his allowance was increased to 700 grams, and, on this not proving quite sufficient, to 800 grams, from November 28. By January 30, 1897, the mother's milk had practically disappeared. The infant weighed 10,200 grams, and was getting 1000 grams of milk per day. This amount had to be increased on February 27 to 1200 grams, but on the whole his curve is excellent, and, indeed, quite above the average.
A woman named Men____, after the usual ten days' stay, left the hospital on October 22, 1897, when her infant weighed 4700 grams; as on her first appearance at the Consultation on November 27 he was only 5320 grams, the average gain per day had not exceeded 19 grams. She told me that, not having enough milk for the child, she had been giving him cows' milk in addition to the breast-feeds. I prescribed 100 grams of sterilised milk, and the infant increased steadily (Fig. 93). On January 8 the menses reappeared, and the child lost weight slightly. I gave 150 grams per day, and on the 12th raised this amount to 200. Again I had to augment the supply; on February 1 I made it 375 grams, but this did not long remain sufficient. On February 26, 450 grams were required; on November 5, 600; and on March 8, 700. On April 9, 1898, the mother's supply having finally ceased, the nursling was given a daily allowance of 800 grams, which, on April 16, was raised to 900. A little farinaceous food was added on June 10. On September 2 he weighed 8950 grams; as on the 9th and 16th he had lost 60 and 170 grams respectively, I increased his sterilised milk to 1000 grams. Immediately he began to gain, and on November 4, although barely thirteen months old, scaled 10,120 grams. A subsequent lactation in this woman followed the same course.
Every Wednesday a woman brings her little grandson, Su_____, to the Consultation. He was born here on September 10, 1898. Breast-fed by his mother, he weighed 4500 grams on September 30, having gained 600 grams since birth. The mother, being unmarried and poor, had to work to live. The grandmother brought the child to me on October 7, and begged a little sterilised milk. I refused, for I make it a rule to insist, whenever possible, on breast-feeding, and, moreover, I object to children being brought to the Consultation by any but their mothers. "But," pleaded the grandmother, "we must live, so my daughter must work. Her employer allows her to leave the factory only at meal-times. She suckles her child then. What would you have us do? We are too poor to give the little one a nurse." "If I give you cows' milk," I said, "how long will your daughter be able to suckle? Her milk will soon disappear, and the child will be exposed to all the risks of artificial feeding." "I assure you," replied the old woman, "that my daughter will give the child every drop of milk she can produce. If you do not grant me the milk we shall have to buy it, and not only will this be a great burden to us, but, further, any milk we can obtain will probably be inferior to that which you distribute. Give me the milk, sir, and you will see how well the little one will be cared for." Needless to say, gentlemen, I gave way. On October 7 I gave 200 grams of sterilised milk per day; on the 28th, 250; on November 18, 300; on November 25, 350; on December 9, 400; on February 3, 450; and on April 28, the mother's supply having altogether ceased, 675 grams. On May 12 the infant weighed 7210 grams. We had ended, as I had feared, with artificial feeding, but the infant had reached seven months, and was of more than average weight for his age (Fig. 94).
Mothers who live in the whirl of modern society life, eager though they may be to suckle their children, are often incapable of nursing, because they produce but little milk. A wet-nurse was formerly their only resource, but, nowadays, sterilised milk may be used to make good their deficiency. I could cite to you many cases in which I have used it to supplement the scanty supply of such mothers. They are very grateful for its help, since it not only spares them the worry of a wet-nurse -- in itself a no uncertain blessing -- but also the mortification of having their children suckled by a stranger.
There are other ladies again who, in spite of their desire to nurse, feel that they have obligations beyond their domestic circle which they are in duty bound to fulfil. They replace their breast-feeds, during that portion of the day when they go to pay their social tax, by one or more bottles of sterilised milk. Such mothers are often excellent nurses; their children thrive, and, when the time comes for weaning, this mode of feeding is found greatly to simplify the process.
Mixed feeding is an inestimable boon to mothers of twins, for they can rarely provide enough to satisfy the needs of both. Let me give you two out of my many cases.
A frail and miserable-looking woman, named G____, was delivered of twins, a boy and a girl, on January 27, 1893. The boy weighed 3800 and the girl 3420 grams, when they left hospital (Fig. 95). The mother was then receiving 300 grams of sterilised milk with which to complete their feeding. This amount had to be increased from time to time -- on February 10 to 400 grams, March 10 to 600, and March 31 to 1200. The mother's milk having ceased on June 30, the feeding became entirely artificial. Although they lived in a small, squalid, overcrowded room, the infants continued to thrive. Their progress was arrested for a time by an attack of bronchitis at the end of December, but on March 9 the boy weighed 9940 and the girl 9040 grams.
A son and a daughter were born to a woman named L_____, on December 10, 1892. When they left hospital on December 22, the girl weighed 3080 and the boy 2900 grams (Fig. 96). They were brought to the Consultation on December 30, weighing 3380 and 3090 grams respectively. As they lived far from the hospital, I gave the mother a steriliser, so that she might prepare the children's milk at home. The mother lavished great care on them, and they throve. But on July 1, 1893, having some business to do, she entrusted them for the day to a friendly neighbour; on the next day both had diarrhoea, and in less than twenty-four hours the girl lost 600 and the boy 370 grams. Happily they recovered, and on January 5, 1894, weighed 9800 and 9300 grams respectively.
I shall not repeat what I have already told you relative to the rearing of the children of the wet-nurses at the Maternité. Here, at the Clinique Tarnier and in many similar institutions, the same plan is successfully followed. 
In our statute books there is an excellent measure for the protection of infant life, known as "Roussel's Law." Among many admirable clauses there is one which prohibits mothers from suckling any but their own infant till it shall have completed the age of seven months. There are many more mothers than good nurses, and it seems to me that by this clause an undesirable restriction is placed upon breast-feeding. In one case which came under my notice a wet-nurse was threatened with legal proceedings for suckling a nursling when her own child was not seven months old. The nursling was then returned to its parents, and they, despairing of finding a wet-nurse whose milk was not what they called "too old," fed it on the bottle, and it died of diarrhoea.
I think that a mother who has suckled her child for several months might, if authorised by her medical attendant, introduce in gradually increasing quantities sterilised milk into its diet. She could thus divert, without prejudice to her offspring, a portion of her milk to another nursling, and the two, carefully supervised, would steadily thrive. Perhaps, after a few months, even a third might be added. The first nursling, like the wet-nurse's own child, could be put on mixed feeding, and the new-comer given the breast exclusively.
A good wet-nurse, under medical supervision, might thus steer several children through the dangers of early infancy and launch them in safety upon mixed and artificial feeding. By this means the scarcity of good wet-nurses could be counterbalanced, and full advantage taken of the few at our disposal.
Artificial feeding, the rearing of a child exclusively on animal milk, is sometimes, unfortunately, a necessity from birth, for some infants have congenital abnormalities which prevent suckling; others persistently refuse to take the breast; and others again seem to be unable to digest human milk. It may be that the mother cannot suckle; in some, the nipples are represented only by depressions on the summits of the mammary glands; in others, ill-health contra-indicates nursing; while others, attacked by acute infectious diseases, are forced to wean. The choice then lies between a wet-nurse and artificial feeding. The results obtained from careful artificial feeding are excellent, and many practitioners prefer it to confiding the child to a stranger, or introducing an element of potential disturbance into a peaceful household.
In July 1892 a country doctor, one of my old pupils, called me to see his wife, who, he thought, was about to develop puerperal fever. On my arrival I was happily able to reassure him, for the alarming rise of temperature was due to a simple mastitis. The mother, however, had absolutely no milk, so attempts were made to procure a wet-nurse, and I advised, in the meantime, the use of sterilised milk. The country was scoured in a vain search for a wet-nurse, till the parents, reconciling themselves to the inevitable, settled down to rear the child on animal milk. At birth the child weighed 3000 grams. On November 23, at the age of five months, she was 8250 grams (Fig. 97), and the proud father wrote to me that she was without exception the strongest and healthiest child he had ever seen, and he felt absolute security in her mode of feeding.
When one or both parents are syphilitic and the mother has no milk, artificial feeding must be adopted. You have no option. You must not expose a wet-nurse to the risk of suckling in such a case. Let me cite to you two typical instances.
After several pregnancies productive of dead fetuses Dr. X_____ and his wife were suspected of syphilis and treated accordingly. A living daughter was born to them in September 1892. She weighed 3550 grams, and during the first fortnight gained on an average 26 grams per day. An ulcerative eruption appeared on the child in the third week, but it was not a typical syphilide. The mother had practically no milk, but, in spite of the father's entreaties, I refused to take the responsibility of recommending a wet-nurse; the child was therefore fed on sterilised milk. She made very satisfactory progress, and her curve was above the average. On December 14, 1892, she weighed 5250 grams, and on July 6, 1893, had reached 8780 (Fig. 98).
M___ C____ had syphilis, and his wife aborted several times. He was given mercury. His wife conceived; she was put on anti-syphilitic treatment, and on July 5, 1893, gave birth to a full-term, living, and healthy son weighing 3150 grams. As the mother's supply soon became insufficient for his needs, sterilised milk was prescribed. On August 16 he weighed 4480 grams; on November 15, 7560, and on January 15, when the mother's milk finally disappeared, 9200 grams. He never presented any specific lesion, and his curve was excellent (Fig. 99).
I have had many similar cases, and Professor Fournier, the eminent authority on this subject, has published some interesting observations, in which he also emphasizes the inestimable advantage of artificial feeding for these tainted infants.
Should cows' milk be given undiluted? It is generally supposed to be harmful to infants, owing to the excess of casein it contains compared with the human product. To counteract this defect great quantities of water are usually added to the milk. The dilution varies with age: at first, three parts of water are added to one of milk, then two; then equal parts of each are used, then two of milk and one of water, and so on to the fifth or sixth month, when undiluted milk is reached. But casein is not the sole constituent of milk. It contains also butter, sugar, and salts, all of which materially contribute to its value as a food. Diluted cows' milk is generally deficient in these substances, and therefore forms but a poor substitute for a mothers' milk. To obtain sufficient nourishment on this attenuated diet infants are obliged to absorb great quantities of fluid, which causes them to pass a large amount of urine. They are almost always crying from hunger, whereas infants on undiluted milk wait contentedly for their next meal.
An infant, one of twins, was first fed on undiluted sterilised milk; from the second day the increase was on an average 21.6 grams per day (Fig. 100). Then one-third of its bulk of water was added to the milk; during the next five days he gained only 6 grams per day. Once more he was given pure milk, and he increased normally again. The diet of the other twin was varied in the same way with a similar result.
Another infant, who was born on August 22, 1893, weighing 2485 grams, and who was being artificially fed, was brought to me on December 8, 1893, because his rate of growth was very slow. As his weight was 4300 grams, he had increased by only 18 grams per day. He was receiving diluted milk, but on placing him upon pure milk, his daily average increase rose to 30 grams. On February 18 he weighed 6480 grams. The second part of his curve compared with the first affords a striking demonstration of the relative values of pure and of diluted cows' milk as foods for infants (Fig. 101).
One day an engineer entered my consulting room. "I am bringing to you," said he, "my child one month old. He is in the next room with my wife, but I want to tell you beforehand that I have had syphilis, and that my wife, without her knowledge, was treated for that complaint during her pregnancy. Our child was born at full term, but he has had to be fed on cows' milk, as my wife could not suckle and I did not wish to bring in a wet-nurse. He weighed 3000 grams at birth and has not gained since. I am afraid that he also is infected, and I have come to see if you can do anything for him."
I examined the child; he was wizened, wrinkled, and puny, but he showed no trace of specific disease.
"How much milk do you give him?" I asked.
"Half a litre per day."
"Half a litre of undiluted milk?"
"No! he is but newly born. I give him two parts of water and one of milk."
"Come, sir, you are an engineer and accustomed to calculate. Let us reckon this up. The child gets 500 grams of liquid per day. Now, if you are using good milk, each litre will contain 870 parts of water and 130 of solids, consisting roughly of 40 parts of butter, 50 of sugar, and 40 of casein and salts.
"Now, if you add two parts of water to one of milk, a litre of the mixture will contain one-third of the normal amount of solids; 130 / 3 = 43.3 grams.
"Your infant takes only half a litre of this mixture, so it gets half of 43.3 grams, i.e. 21.65 grams of nutritive matter per day. The child is suffering from starvation."
Thenceforth the infant received 500 grams of pure sterilised milk. At the end of one week he had gained 200 grams, and he continued to thrive to his parents' entire satisfaction.
Obviously, when an animal takes animal milk of poor quality it has to absorb large quantities. Some specimens of asses' milk sold in Paris contain very little nourishment. On November 7, 1899, I attended at the birth of a child, Jean X____, who weighed 3120 grams. As he had a hare lip he could not suck, and was fed artificially. I began by giving him asses' milk. Although he took 450, 500, 600, 650, and then 735 grams per day, his curve did not rise as well as I desired (Fig. 102). Twice I analysed this milk; the first time I found 9 and the second 11 grams of butter per litre. From November 20 I substituted 50 grams of cows' milk at one feed each day. On the tracing the asses' milk is represented in blue, the cows' milk in red. Observe how the blue column descends from day to day while the red one rises. By November 28, cows' milk alone was being given, and the curve continued to rise steadily, although only 450 grams were being ingested instead of 735. The bulk of the infant's diet had thus been reduced by 285 grams, and yet he was not underfed, as the cows' milk contained 40 grams of butter per litre, whereas the asses' milk had only 9 to 11 grams.
It is alleged that the casein of cows' milk forms large clots in the stomach and gives rise to digestive troubles. This is obviated if the milk be heated in a steriliser at a temperature of about 100° C. "According to my experiments in vitro," says Chavane,  "the clot of milk thus sterilised offers no resistance or sense of elasticity to the finger, on pressure; it yields like a thick fluid, such as cream, and on microscopical examination, although the fat globules are not appreciably altered, the particles of casein are found to be smaller and more homogenous. It differs from the fine clot of human milk; it is distinct from that obtained from asses' milk, but it is quite comparable with the latter as regards the size of the casein particles. Obviously this sterilisation below boiling-point, heating to 100° C., modifies the casein so as to affect the state of subdivision of the clot, and also the molecular structure of the particles." This, probably, explains why milk thus sterilised is more easy to digest than either fresh or boiled milk.
Sterilisation is greatly simplified by the use of undiluted milk. It is a complicated process when dilution has first to be performed according to the infant's age. When the same milk is dispensed to infants of all ages the mother's duties are made easy, and the work of Consultations and crèches is greatly facilitated.
When I first advocated the feeding of infants on undiluted milk, critics asserted that infants could neither support nor digest it, and that it was responsible for quite a catalogue of evils -- digestive troubles, rickets, eczema, urticaria, &c. I have never seen any bad results from its use, and infants, thriving on it, may be seen daily at the Consultation. The milk I distribute contains 37.35 grams of butter, on an average, per litre, and I have obtained excellent results from it. In 1894 I stated my position on this matter as follows: "I carefully refrain from asserting that during the first months of life milk ought invariably to be prescribed unmixed with water. Just as infants may not be able to support their mother's milk if it is too rich, so they may not tolerate some specimens of cows' milk overcharged with butter or casein. Cows' milk is not of constant composition: it varies with the breed of the animal, the feeding, and other factors. Again, infants may or may not be healthy, and in the latter case their digestive tube has need of judicious treatment. Thus, each infant must be dieted according to the existing conditions, and it may be of service to add a variable quantity of ordinary water, barley water, lime water, or other diluent to its milk. My custom is to prescribe pure milk, and any departure from this is determined upon only after careful observation."
As regards artificial feeding from birth, my experience is yet too limited to warrant any dogmatic statement of the most advisable method during the first few weeks of life. As I always endeavor to insist on breast-feeding, my cases are not numerous enough to base any definite opinion upon. Probably, in those infants who do not tolerate pure milk at the beginning some form of digested milk, such as that which I used for the weaklings, might be found of service.
I warned you against overfeeding breast-fed babies. The same precautions must be taken when they are fed on sterilised milk, in order to avoid digestive troubles.
An infant I was treating at the Charité was taking 700 grams of milk and increasing in weight at a remarkable rate. On the twenty-fifth day vomiting began without diarrhoea. I reduced his allowance to 500 grams per day (Fig. 103), and on the twenty-seventh day the vomiting ceased, and the infant commenced normally to increase.
But treatment is not always so rapidly successful. Merle records a case of a child called Roger X____, who was born on January 26, 1894, with a weight of 4000 grams. He was exclusively breast-fed till February 18, when he weighed 4650 grams. The mother's milk then disappeared, and the infant began to lose weight. He was given undiluted sterilised milk, but, as he seemed to support it with difficulty, barley water was added. On April 1 he weighed 7100 grams. He drank greedily; his daily allowance was almost 2000 grams per day, and the inevitable happened; he was seized with colic, diarrhoea, and vomiting, and in five days his weight diminished by 700 grams. The quantity of milk was at once reduced to 1250 grams, and towards April 20, he began slowly to improve. The vomiting ceased, his weight augmented slightly, but, as his mother remarked, "he seemed to be dying of hunger." On April 24 he was given 4000 grams of milk and barley water. On May 25 this amount of pure milk was given. The child continued to grow on the same bizarre scale, so that on July 2, when he was aged five months, he weighed 11,800 grams (Fig. 104).
Parents, midwives, and nurses frequently give enormous amounts of fluid to infants. In one of my cases a nurse gave an infant a few days old 800 grams of undiluted sterilised milk. She seemed astounded when I pointed out that 800 grams per day, for an infant weighing 3 kilograms, was equivalent to 16 litres for the average adult of 60 kilograms (800 X 20 = 16,000 grams). Although an infant, having to grow as well as to live, requires relatively more than an average adult, this was nevertheless a preposterous amount.
It is more than probably that the evil effects attributed to rearing young babies on undiluted milk are in reality due to overfeeding. Many medical men are now partisans of undiluted milk. Variot  states that sterilised milk is well supported by the newly born, and that since its introduction dilution is no longer necessary. During the first six weeks, however, he usually adds one-third of its volume of water and a little sugar. Comby,  in 1894, wrote: "Dilution is rarely required, and the sterilised milk of commerce is perfectly tolerated by even the youngest of infants." Lazard  says: "Infants, who are after all the best test of the quality of milk, support sterilised milk admirably. I recommend it undiluted. Experience has taught its great value, for not only is it easily tolerated by healthy infants, but it is also the best remedy in certain cases of diarrhoea, and has saved merasmic cases veritably from the jaws of death." Drapier, , who has obtained such marvellous results at his crèche at Rethel, uses only undiluted sterilised milk. Ruffié  writes: "On the subject of artificial feeding I am without bias, but the results I have obtained convince me that the use of undiluted sterilised milk, as advocated by Professor Budin, is best. I always recommend it to mothers, for not only has it the merit of simplicity, but it also does away with dilutions and manipulations which tend to compromise the purity of the milk."
Bonifas  says: "When I was made Medical Inspector of Nurslings in 1893, I was quite ignorant as to whether infants ought to receive milk diluted with much or little water. The authorities I consulted were at variance; as some wished to dilute it by at least half, and others to give it pure, I resolved to test the matter for myself. After two years of minute investigation, I am firmly convinced that undiluted milk should be given during the first months, and even weeks, of an infant's life. This is not an opinion, it is a logical conclusion from a mass of facts."
Gillet,  an authority on infant hygiene, discusses the question as follows: "Formerly, practitioners had no definite rules to guide them in artificial feeding, for prominent writers disagreed. Now it is otherwise: undiluted sterilised milk has solved the difficulties. I invariably prescribe it, and I have never seen any ill effects from its use. For a few days after birth some infants do not tolerate it well, and for them it may be slightly diluted for a short time. However fixed the question may seem in theory, there is no immutable law in practice, and the most suitable diet for any particular child can be ascertained only by experiment; but undiluted milk will be found to answer in most cases. The method of dilution has for its object the approximation of the composition of cows' milk to that of human milk. This is only one of the desiderata in artificial feeding, and one to which we, nowadays, attach much less importance than heretofore."
At our next meeting we shall study how much undiluted sterilised milk an infant ought to receive.
 Millet, L'Obstetrique, 1897, p. 51; Charpentier, La Revue Philanthropique, Nov. 1898, p. 5.
 Du Lait Sterilisé, Paris, 1893.
 Variot, Journal de Clinique et de Thérapeutique Infantiles, Feb. 13, 1893.
 Comby, La Médicine Moderne, March 14, 1894.
 Lazard, Journal de Clinique et de Thérapeutique Infantiles,1895, p. 886.
 Drapier, Rapport sur le fonctionnement de la Crèche Hippolyte Noiret pendant l'année 1895. Union Medicale du Nord-Est, 1896.
 Ruffié, La Gouttette ou la Diarrhée verte des Nourrissons et son Traitement par la Lait Sterilisé, Paris, 1899.
 Bonifas, Le Progrès Medical, Feb. 24, 1900, pp. 113-116.
 Gillet, Formulaire d'Hygiène Infantile Individuelle, Paris, 1898, p. 113.
Fig. 92. Curve of an infant reared on mixed feeding.
Fig. 93. Mother had not enough milk. Child reared on mixed feeding.
Fig. 94. Curve of an infant at first breast-fed by its mother, who had plenty of milk. As she had to go out to work, mixed feeding was practised.
Fig. 95. Twins (blue, boy; red, girl) reared on mixed feeding, as the mother had not enough milk adequately to nourish both.
Fig. 96. Twins. Mixed feeding (blue, boy; red, girl).
Fig. 97. Artificial feeding. Mother had no milk, and a wet-nurse could not be obtained.
Fig. 98. Congenital syphilis. Mother had no milk. Artificial feeding.
Fig. 99. Syphilis in the parents. Mother had not enough milk. Artificial feeding.
Fig. 100. Effect on an infant's weight of feeding with diluted milk.
Fig. 101. Artificial feeding, first with diluted (blue) and then with undiluted milk (red). The blue part of the curve persistently falls away from the normal line which the red part rapidly approaches.
Fig. 102. Hare-lip. Artificial feeding. Of asses' milk 750 grams were required per day, of cows' milk 450. The curve steadily rose.
Fig. 103. Digestive troubles arising from an excessive allowance of milk.
Fig. 104. Digestive troubles due to over-feeding.