=The Cure of Chronic Bronchitis by Deep-breathing Exercises.=—The upper part of the body must be nude and the exercises taken before a mirror, so that the woman can watch the movements of the chest and abdomen, see that all the hollows of the chest are filled out during forced inspiration, and that the muscles of the abdomen are properly retracted. For the average woman this last will be the most difficult; in beginning these exercises she will find that it will require all her concentrated energy and will power to cause a retraction of these disused muscles. Patients with chronic bronchitis do not have the ability to perform forced respiration properly. The respirations are too superficial, and the respiratory movements are not properly performed. As respiration is ordinarily performed, the partial expansion of the upper part of the chest is accompanied by a contraction of the abdominal muscles, whereby the diaphragm is forced upward, with the result that the lower part of the lungs remains very slightly expanded, whereby the circulation as well as the removal of mucus is imperfectly performed. This lack of forced respiration is a frequent cause of acute bronchitis running into a chronic form. In chronic bronchitis it is especially in the lower part of the lungs that stagnation of the secretions takes place, and they can only be dislodged from the mucous membrane by forced abdominal expiration and the ascent of the diaphragm. This causes a cough which expels the mucus, and forcible abdominal expiration and cough are the only means of drainage of the lower and deep-seated parts of the lungs. Further, in forced respiration the muscle tissue of the bronchial tubes contracts, which certainly does not take place in ordinary respiration, but, on the contrary, this tissue atrophies. Other beneficial results from forced respiration are increased oxygenation, improved nutrition, changes of a mechanical nature, ventilation, and disinfection of the lungs, massage of the lungs and pleura, and drainage. No other method of treatment is so successful in the cure of chronic bronchitis not dependent on disease of the nose and throat. In from two to six weeks of treatment, in which there is a profuse discharge of mucus, it will be found that the bronchial tubes have cleared up, provided that the patient is supplied with an abundant supply of fresh air day and night. Methodically practised, deep breathing is not only the surest cure, but also the safest stimulating expectorant. =Relation of Colds and Influenza to Pneumonia and Tuberculosis and their Prevention.=—We have already seen that bacilli are not only the cause of acute infections, but also of chronic bronchitis, and that this was especially true of the bacillus of influenza and the pneumococcus of pneumonia.