Too frequent feeding is a common un derlying cause of infantile indigestion, and the giving of too large a quantity of food in the bottle is another factor. In hot weather fermentation of the food, added to the depression of the infant's vitality resulting from the heat, gives rise to summer diarrhcea. Infants under two years are the greatest sufferers, but preventive treatment, if properly carried out, would do much to mitigate this veri table scourge. Cleanliness of the city streets and watchfulness of perishable food-products are important sanitary measures. If the dairy could be properly supervised and the milk delivered to the city consumer within twelve hours after milking, there would be very little sum mer diarrhoea. Another way that the city can help in this work is by provid ing parks and planting many shade-trees in the streets. H. D. Chapin (Med. Ilecord, July 1, '99).
For the exciting cause, therefore, of the severe diarrhceas of infancy we must seek further; such a cause, it is now al most universally conceded, exists in the growth in the intestinal tract of toxin producing bacteria. Such bacteria, prob ably, in the majority of cases are intro duced with the food. During the colder seasons of the year these bacteria, while present more or less everywhere, remain quiescent, but, with the onset of warmer weather they multiply in any suitable medium with a rapidity almost in credible. No article of infant-diet ap pears to be so readily contaminated as cows' milk; not only is it liable to be in fected from many sources, but at the same time it affords an excellent culture medium for almost all forms of bacteria. Hence to it, more than to any other article of diet, are disastrous effects at tributed. Moreover, it was formerly sup posed that the acidity of the gastric juice, in the infant as in the adult, stood guard with a certain amount of germicidal power at the portal of the intestinal tract, where, even under normal condi tions, there appears to be little hindrance to bacterial growth. Traube and Esche rich, however, have shown that in young infants the stomach has but slight power of either digestion or absorption, and is rather a receptacle into which the milk is received for coagulation, and from which it quickly passes into the small in testine, where it meets the proteolytic ferment of the pancreas, relatively well developed even at an early age. Owing to this there is practically no hindrance to the development of bacteria in the alimentary tract of the infant, save the rapidity and completeness with which the digestive process is performed. Indi gestion, therefore, by permitting fer mental changes, furnishes the conditions under which any pathogenic bacteria, either just introduced by means of con taminated food or present in the canal but previously hindered in development, may flourish and evolve their poisonous toxins.
As additional predisposing causes, we may add that all conditions which lower the vitality of the infant tend to impair digestion, and, to this extent, favor the development of diarrhcea. Defective hy gienic conditions, previous acute disease, and malnutrition in all its forms, espe cially rachitis, syphilis, and tuberculosis, appear to act in this way. Summer-heat directly prostrating the nervous system, overexcitement, and occasionally the nerve-irritation accompanying dentition, have all an influence more or less dis turbing on digestion, and may, therefore, be regarded as predisposing causes of diarrhoea.
In a report of 54 cases of children, ranging from two and one-half months to four years, with digestive diseases, the gastric juice was examined 119 times, both qualitatively and quanti tatively. Of the children, 6 had dys pepsia, 11 acute gastro-enteritis, 6 acute enteritis, 5 acute colitis, and 26 chronic gastrointestinal disorders. Absorption occurs more rapidly under than over four years of age. Absorption is most affected in acute gastro-enteritis, next in dyspepsia. The stomach is least af fected in acute dyspepsia and enteritis: most affected in acute gastro-enteritis and chronic diseases. T. von Hecker (Jahrbuch f. Kinderh., Nov., 1902).
General Pathology. — The normal aces of a healthy infant fed at the breast should be of a smooth and homogeneous nature, of semisolid consistence, of a dull-lemon color, and of a not unpleasant odor. They should have an acid reaction, due to the presence of fatty acids and of a small amount of lactic acid. Fat, chiefly in the form of neutral fats, fatty acids, and soaps, is almost always present, sometimes in considerable amount. Sugar is never present. Protcids, in breast-fed children, are present in small amount; but, in infants fed on cows' milk, casein is met with in considerable quantity, rendering such motions firmer in consistence, paler in color, larger in amount, and with a distinctly more un pleasant odor. In breast-fed infants, under normal conditions, the bile elements for the most part remain un altered, but, as the diet becomes changed, the biliary pigments become decomposed, and, with the mixed diet of the second and third years of life, the faeces resemble those of the adult, excepting that they are less firm and more or less acid in re action. Mucus is present to a consider able extent; also epithelial cells, chiefly of the columnar variety.