The work performed in suckling, is not inconsiderable: the pressure of suction ;mounts in the first week to about It) to 20 cm. water, and in older infants to TO cm. or more. The infant thus performs a rather con siderable amount of work in taking its food, NVIlich work fatigues it at the proper time and proteets it agairst excessive feeding. At the same time it stimulates I he secretion of the gastric juice (Pfaundle•), either by an increased secretion of saliva, or, more probably. through special reflexes.
During the first days of life the infant should stickle both breasts at each meal, but toward the end of the first week strong babies should receive only one breast. The breast is then emptied completely and the infant receives the benefit of the last milk, which is richer in fat. Emptying the breast is very favorable also for the production of milk. In cases of weak infants and insufficient milk supply, the production of milk can frequently he increased to meet the demand by putting a strong infant to the breast. If an infant receives only one breast at a meal it has to perform more work in suckling, and strong infants can In this without injury. But weak, easily fatigued, and premature infants should always receive both breasts if the milk production is not very abundant.
Before nursing, the mother should express some of the milk, be cause the first milk is not sterile, on account of the entrance of bacteria into the milk-duets. It is important to cleanse the nipple with boiled water before and after nursing. It is neither necessary nor desirable to use antiseptic fluids. The mouth of the infant should not be washed before or after nursing, since, according to the investigation of Epstein, this may easily lead to injuries of the mucous membrane, with their But the exterior parts of the mouth, and particularly the corners, must be kept clean.
The secretion of the mammary gland in the first days post partum, the colostrum, differs very much in its composition from the Milk of other periods. Its physiological significance is pointed out in the chap ter on the milk, and here only the essential difference from the milk proper, which lies in the high content of albumin, \yin he emphasized. According to (the elder), the milk during the first week is as follows: Against this introduction of food there, is the excretion in the urine, feces, and insensible perspiration. (In regard to the latter, see Table 8,