It is the same way with the restriction of alcohol. In countries n-here the taking of weak alcoholic drinks, especially in the form of light beer, is customary, we should not uselessly stop a custom which has a favorable influence upon the appetite and temper of the nurse. The frightful pictures painted by the total abstainers with a view to teaching a fear of alcohol, are not to be dreaded. On the contrary, I would rather mention the good effects of moderate beer-drinking. Abuse of spirits, of which we have from earliest times disapproved, can cause in the child disturbance of development, and injurY to health, and is strictly to be forbidden. A number of such cases have been collected by Madan.
Also \ve must riot allow the wet-nurse to have certain drugs, which we know from experience and from experimental research can be ex creted in the milk, and which are bad for the infant. Nevertheless the number of these preparations is inuch smaller than was formerly supposed. We recognize as certainly excreted in breast-milk only salicylic acid, codeine, and mercury (Thiernich), while we can, as a result of animal experiments, exclude the excretion of opium, morphine, atropine, and large (loses of alcohol.
Finally there remain to be mentioned those diseases of the nurse, such as active tuberculosis, severe uncompensated cardiac disease, advanced nephritis, and certain nervous disorders, which can result in such deterioration of the milk that disturbances of nutrition are to be feared. Such diseases can also cause injuries on the one hand through the danger of infection, on the other through the influence on the consciousness and intelligence of the nurse.
It should suffice to compel us to regard breast-milk as the only thoroughly suitable food, if we simply reflect that the breast-glands of the mother grow to maturity and prepare their fluid nourishment. while the fcetus is developing in utero, and under the influence of the internal secretion of the growing placenta and ovaries. This was first shown experimentally by IIalban. Such teleologic conclusions find their confirmation in the observation of children who are normally born and are nourished rationally in the natural way, in the expe rience of farmers with suckling animals of various breeds. and in studies of the comparative nutrition of such animals. ezerny and Keller in their clear explanations were the first briefly to demonstrate the protection against disturbances of nutrition, and the very marked relative inununity attainable in sucklings through the great superiority of breast-feeding.
Everything that we know, both of the physiology of digestion in newborn infants and sucklings, and of the structure of the alimentary canal, and of the functionating power to be predicted froin this structure, serves to strengthen us in this opinion.
The construction of the cavity of the mouth, with it$ poorly de veloped salivary glands, and the slight power of its digestive ferments, as well as the functional preponderance of the muscles of its floor over those of mastication proper, and the absence of teeth; demonstrates the necessity of an exclusively fluid nutriment. The full develop ment of the sucking and swallowing reflexes at birth allow the rapid taking in and passing along of such nutriment. The anatomical ar rangement of the stomach, its small capacity, its weakly developed musculature, its elastic tissue, which in the first months of life is scarcely noticeable, and is arranged only about the greater vessels iFischl); the slig,ht differentiation of the two varieties of gland cells, on the cor rectness of which I must insist, on the ground of former and recently repeated researches, in spite of observations to the contrary ; the shortness of the crypts and the relatively deep extension of their epi thelial layer into the necks of the glands; and finally the quantita tively slight production of a secretion of weak digestive power,—all these facts assign to this organ the role of a food reservoir, rather than that of a place of digestion of any considerable importance. Its func tion of digestion develops fully at a relatively late period, toward the end of the second year. In the suckling, intestinal digestion represents most of the assimilative function. The stomach performs but little digestive work, and therefore requires a fluid nutriment. which it can deliver over to the intestine without thorough preliminary preparation. We know, from the fundamental researches of Pawlow and his pupils, how close is the connection between the digestive power of the stoniach, and of the different divisions of the intestine. We know that a normal course of gastric digestion is a necessary condition for proper intes tinal digestion, and that the acidity of the chyme stimulates the great digestive glands of the abdomen to the secretion of their specific enzymes. We understand fully that any interruption in the regularity of the succe.ssive steps of this complicated process results in disturb ances which manifest themselves throughout the metabolism. The relative length of the bowel in comparison with that of the whole body, the weakness of its musculature, its hardly noticeable supporting elas tic tissue, its richness in lympliatic.s and blood vessels, its nerve fibres, for the most part without sheaths, allow it to play the part of a very sensitive organ of absorption, 6tich an organ can accomplish the chemical breaking tip of food only when the food is presented in the form most easy of assimilation, and can utilize it to an extent winch corresponds to the needs of the growing organism.