Many lives all winter in the cold zone in a heated box where the killing cold makes adequate ventilation impracticable. The inside air is soon badly polluted with the fumes of cookery, may be with tobacco smoke, and the filthy emanations of body and breath.

If man were no tougher than the fish, he would die in the polluted air of his home as the fish dies in the polluted water of its tub. He gets “used to it” because of the marvelous powers of adjustment of his body. But the body does not make man immune of his polluted Environment, and he dies by inches.

An adult poisons nearly a barrel full of air at each exhalation. That foul air he breathes over and over again all winter in his home. The results are colds, coughs, sore throat, pneumonia, etc., etc.