Earlier in this inquiry we have traced the interdependence, the unity of man’s three natures—the physical, the mental, and the spiritual,—and the value of correct breathing to the whole man is in perfect keeping with that interdependence. In the process of digestion, upon which physical health so largely depends, we create poisons within ourselves and accumulate waste matter. The organism must be momently purified of these wastes, or putrefaction quickly follows. Autotoxins form, as the doctors say. The function of breathing, when properly controlled, affords the quickest and best method of cleansing the blood of these impurities. If we have not this proper control, the poisons are not eliminated and the supply of blood to the brain is vitiated. Just as the body cannot perform its functions well if we are compelled to live upon tainted food, so the brain cannot do its work well if the blood—its food—is impure. Breathing which expands the diaphragm so purifies the blood as it passes through the lungs, that it becomes an important factor in maintaining health and poise in body and mind, which in their turn react upon the spirit. This sort of breathing is more common among men than among women, due in part to natural physical differences and in part to dress. Man breathes largely from the abdomen, while woman breathes chiefly from the chest, expanding only the upper portion of the lungs. This is partly a natural and partly an artificial necessity, due to the pressure of the corset upon the diaphragm. Both men and women would find their physical health improved and their outlook on life broadened and brightened by proper control of the function of breathing. If we are sleepless, nervous, too alert, as well as if we are heavy, dull, and inactive, we will find it worth our while to try conscious breath control. It takes but a comparatively short time to re-educate the automatic centers into correct breathing and the result is always good. It no less behooves the man who is trying to live largely on the rational plane, than the man who is living wholly on the physical plane, to make his efforts both easier and more effective by such simple attention to natural laws. The next time you are worried, depressed, or sleepless, change the air of the room and try deep and correct breathing for a few minutes. You will be surprised at the complete change wrought in you, if you are not suffering from some serious organic breakdown which needs skilled attention. And even that condition may be helped by proper breathing. But we are not to forget that, like calisthenic and gymnastic exercises, the training of the breathing is really little more than a device for correcting the results of wrong living and only a substitute for right living. The man or the woman who does plenty of healthful, normal work, who often pants and gets “out of breath,” naturally expands the lungs and has as little use for breathing exercises as for tight clothing.