=The wet nurse= is always a tribulation, which must be endured until the child can be put on artificial food. She should have a Wassermann test before entering upon her duties. Syphilis, tuberculosis, and gonorrhœa must be guarded against. She must be kept like the family cow, in a placid frame of mind, fed on nutritious food that is not too rich, and exercised enough to keep the blood circulating. Light housework and duties that take her out of doors part of the time are advisable. Her moral character can only be assured through those who have known her. If she brings her own child with her, she will need watching to provide for an equable distribution of the milk. The first few days is never a criterion of a wet nurse’s effectiveness. Change of food and surroundings may interfere with her usefulness. =Gas= may complicate the puerperium after Cæsarean section, and even after normal labor. A rectal tube of soft rubber may be passed as high as possible into the bowel and left for some time, or enemas of S. S., turpentine, asafœtida, or milk and molasses may be given. By mouth calomel or mag. cit. is valuable. =Headache= in the puerperium should be watched carefully, and the cause discovered. Pain in the head may be a habit with the patient, or it may be a symptom of some complication either present or developing, such as toxæmia, eclampsia, or acute yellow atrophy of the liver. In general, it is due to milder conditions like exhaustion, too many visitors, excitement, nerves, or insomnia. =After-pains.=—Sometimes patients are greatly annoyed by after-pains. The pain may be due to a clot retained in the uterus or possibly a stimulation of the uterus when the child goes to breast. Gentle massage of uterus, or ergot, quinine, or codeine may be required to bring about the expulsion of the clot or to control the pain. A reasonable degree of after-pain is of favorable significance. (See p. 154.) CHAPTER XVII INFECTION Puerperal fever is a wound infection. The conditions of the pelvic organs during labor and post partum, are well adapted to receive and develop microorganisms, for the healthy antimicrobic power of the vaginal secretion is absent or diminished. A long and exhausting labor, possibly accompanied by hæmorrhage, or terminated by an operation, has diminished the immunity and broken the resistance of the tissues to a dangerous degree. The mucous membrane of vulva and vagina are torn and bruised, the vitality lowered, and the surface covered with bloody lochia, which is an excellent nutritive medium for microbic development. The uterus is a vast, open wound, filled with fibrin, blood clot, and decomposing tissue, while the whole pelvis is maintained at exactly the proper temperature for germ propagation.