The Indian is an absolute believer in the virtue of the outdoor life, not as an occasional thing, but as his regular, set, uniform habit. He _lives_ out of doors; not only does his body remain in the open, but his mind, his soul, are ever also there. Except in the very cold weather his house is free to every breeze that blows. He laughs at “drafts.” “Catching cold” is a something of which he knows absolutely nothing. When he learns of white people shutting themselves up in houses into which the fresh, pure, free air of the plains and deserts, often laden with the healthful odors of the pines, firs, balsams of the forest, cannot come, he shakes his head at the folly, and feels as one would if he saw a man slamming his door in the face of his best friend. Virtually he sleeps out of doors, eats out of doors, works out of doors. When the women make their baskets and pottery, it is always out of doors, and their best beadwork is always done in the open. The men make their bows and arrows, dress their buckskin, make their moccasins and buckskin clothes, and perform nearly all their ceremonials out of doors. Our greatest scientific fighters against tuberculosis are emulating the Indian in the fact that even in the winter of the East they advocate that their patients sleep out of doors. Pure air, and abundance of it, is their cry. “Taking cold” comes, not from breathing “night air,” but generally from inflammation of the mucous membranes caused by impure air,--the air of a heated room from which all the pure air has been exhausted by being breathed again and again into the lungs of its deluded occupants, each exhalation sending with it a fresh amount of poison to vitiate the little good that remains. Men often go to gymnasiums in the city to get exercise. The air is vitiated by the presence of others, and as respiration is increased by the exercise, impure air is taken into the lungs, and the prime object of the exercise is defeated. For it is not so much to develop muscles as it is to stimulate the general action of the whole body that gymnastics should be indulged in. Vigorous exercise demands deep breathing; if the air breathed is pure, the blood thereby becomes more oxygenated or vivified. As this vitalized blood circulates, it carries its life-giving new strength and energy to every part of the body, so that the whole man feels the increased vigor. But let the air be impure, death instead of life is given to the blood. Hence, where possible, all vigorous exercise should be taken out of doors in the pure air and sunlight, and if this is not possible, every door, window, and avenue through which outside air can be brought inside should be placed wide open, and _kept open_ during the whole time of the exercises. If spectators come, and on their account windows and doors are closed, a positive injury is being done to the exercisers. Far better turn out the spectators than shut out God’s pure air.