particularly robust constitution, linger on, weak, ailing, and rickety, until an attack of bowel complaint, or other intercurrent disease, carries them off. The very fact that the secretion of saliva in the young child does not become established until the third month after birth, seems to indicate that before that age farinaceous articles of diet are unsuited to the infant, as saliva is one of the most potent agents in the digestion of starchy foods. Besides, for perfect nutrition four classes of foods are required,―viz., albuminates, fatty substances, carbo-hydrates, and salts. These are found in the most digestible form and the most perfect proportions for the young child in the casein, butter, sugar, and salts of the human milk. The casein supplies the waste of the nitrogenous tissues, as the muscles, and probably the brain and nerves, and by its oxidation, when it has formed part of these tissues, contributes also to animal heat. The butter is essential to the formation of muscular and nervous tissues, and also aids by its oxidation in the production of heat. The sugar is probably entirely heatgiving. The salts form necessary constituents of all tissues.

In nutrition, it is important that tissue change should be rapid, and in young children, where development, as well as growth, is so brisk, this is of especial importance. It is effected by the oxidation of old material, which is then removed, to be replaced by new matter. For rapid change therefore, it is indispensable that no needless impediment should exist to the free oxidation of the tissues. Now, starches, and sugars into which the starches are converted by digestion, have a greater affinity for oxygen than albuminates ; they, therefore, tend to appropriate the oxygen which is required for the removal of waste matters, and so prevent the proper changes from taking place. For this reason alone, and without any reference to their indigestible properties, they form a very unsuitable diet for a young

WOMAN'S MILK AND COW'S MILK COMPARED. 19

Even those children who are fed entirely upon cow's milk are not free from danger. By referring to the table* we see

SPECIFIC
GRAVITY.

WATER. SOLIDS. SUGAR. CASEIN. BUTTER. SALTS.

Woman's milk 1032 67 889-08 110.92 43 64 39.24 26.66 1.38

Cow's milk 1033 38 864 06 135.94 38.03 55 15 36 12 6.64

that the specific gravity of cow's milk is higher than that of woman's milk, and that it contains a larger quantity of solid matters, owing principally to an increase in the amount of casein. On the other hand, the proportion of sugar is less. than that found in human milk. In adapting it, therefore, as a substitute for the natural food of the child, it will be necessary to remedy these differences by dilution with water, and by the addition of a small quantity of sugar of milk. But this is not enough. There is another distinction between the two fluids which it is extremely important to take into consideration. On the addition of rennet, the casein of human milk coagulates into light, loose clots, formed by the aggregation of little flocculi, while that of cow's milk congeals into heavy, compact lumps. The same thing takes place in the stomach of the child, as is shown by producing vomiting in an infant directly after a meal by friction over the belly: the light, loose clots formed from human milk are then readily distinguishable from the dense masses of casein produced by coagulation of the milk of the cow. The difference in the digestibility of these two products is very evident. While the one is readily assimilated without any undue demand upon the digestive powers, the other tasks these powers to the utmost, and, unless a very moderate

* Vernois and Becquerel, loc. cit.

quantity has been taken, will undergo fermentation, and give rise to much flatulence, colic, and perhaps diarrhoea in its progress along the alimentary canal.

Children are, no doubt, frequently found to thrive upon this diet, their digestive power being equal to the demands made upon it. Others, however, and by far the larger proportion, are not equal to this daily call upon their powers. They cannot assimilate this mass of curd. Consequently, unless rejected by vomiting, it passes through them undigested; their wants are not supplied, and they starve for lack of nourishment, although swallowing every day a quantity of milk which would be ample support to a much stronger and healthier infant. Such children are exceedingly restless and irritable. They cry day and night; at one time from abdominal pains excited by the presence in the bowels of this undigested mass; at others, from the hunger which the passage of this meal has failed to appease. The nurses say, very truly, that the "child is ravenous," and that "the milk does not satisfy him ;" but the baked flour, the infant's biscuits, and the tops and bottoms by which they propose to themselves to attain that end, are by no means calculated to do so. Instead of mitigating his distress, they aggravate it; and every additional meal, although it may quiet him for the time, yet,'by the discomfort which it is certain to produce, forms a subject for future complaints. It is, however, often very difficult to persuade mothers and nurses of the importance of what has been stated. They see that the child is wasting under the diet they have first adopted, and therefore will not but infer that something more solid must be required. It is necessary to impress upon them very strongly that a child may actually starve on the fullest diet, and that the presence of large quantities of farinaceous or caseous matters in the alimentary canal is not necessarily followed by any additional supply of nourishment to the tissues. In all cases where the food of an infant is said by nurses to be insuffi

cient, the stools should be carefully examined, and if, as is so frequently the case, they are found to consist of pale, round, hardish lumps, exhibiting in their interior the cheesy appearance so characteristic of a mass of curd, we may safely conclude that it is not that too little is being given, but too much; and by taking the necessary precautions, we may succeed in providing the child with a diet he is capable of digesting.

Besides the weakness produced by the withholding of nourishment, there is an additional cause of debility in the constant attacks of vomiting and diarrhoea to which this indigestible diet invariably leads. Each of these attacks reduces him more and more, and by weakening his digestive power renders him less than ever able to obtain any nourishment from the food with which he is supplied.

Symptoms. The symptoms of simple wasting from insufficient nourishment may be divided into two classes, according to the nature and quantity of the food taken :— Food suitable, but insufficient.

Food unsuitable.

In the first of these classes there are no very striking symptoms. The infant gradually loses his plumpness; his fat slowly disappears; and the muscles get very flaccid and soft. He does not seem to grow. His face becomes pale, and his lips pale and thin. He is peevish as a consequence of his hunger; takes the breast ravenously at the first, and then, if the secretion of milk is scanty, desists at intervals to cry passionately as if in vexation at his inability to obtain the means of satisfying his wants. His skin is moist, and he perspires readily and copiously. The fontanelle is level or slightly depressed. At night he is exceedingly irritable and sleepless. In the day-time he will often lie quietly enough, holding both thumbs in his mouth, and sucking at them until the skin at the sides of the nail becomes raw and abraded. If the milk is poor but abundant, the child is usually very quiet and drowsy, passing

almost all his time asleep. He may even sleep while at the breast,―a sure sign that the milk is thin and serous. The bowels are usually confined, and the motions rather solid, although otherwise natural. No symptoms are found to indicate disease of any particular part of the body.

In this class of cases nutrition is defective on account of the inferior quality and insufficient quantity of the mother's milk, and nothing is added to compensate for these defects. The remedy is, of course, to supply the deficiency. When the required nourishment is given, the wasting stops at once, the peevishness ceases, and the child, rapidly regaining flesh, becomes strong and healthy.

In the second class of cases, where the food is bad in quality, we find the symptoms of defective nutrition combined with other symptoms produced by the irritation of the digestive organs to which the presence of indigestible food necessarily gives rise. The child is dull and languid, his flesh becomes flabby, and he begins to waste. The skin is moist, at the first, although afterwards it is apt to become dry, except about the head; and the fontanelle is, or soon becomes, depressed. The face and body generally are pale, and the complexion sometimes turns yellowish, assuming a half-jaundiced tint, which remains several hours, or even days, and then disappears. The tongue is clean, pink, and moist, and remains so as long as there are no symptoms of acute digestive disturbance. The bowels are irregular and capricious; constipation alternating with occasional attacks of diarrhoea. The common condition is constipation; a stool occurring every second day, consisting of hard, whitish lumps, covered with a stringy mucus, and formed almost entirely of undigested food. Its evacuation is often attended with much straining, and may be preceded by some pain in the belly. The cause of this sluggishness of the bowels is the presence of mucus secreted in unusual quantities on account of the irritation to which the membrane lining the alimentary canal is exposed. This mucus, being coagulated