The reports of various investigators working in both the clinic and the laboratory have definitely established the fact that the nose and related structures bear a significant relationship to the body as a whole. It has been determined in the laboratory that the carbon dioxide-carrying capacity of the blood is greater in a patient who breathes through his nose than in one who breathes through a tracheotomy tube.1 It was found that the passage of air through the nose stimulates the sensory endings of the fifth nerve, thereby reflexly stimulating the vagus nerve, which results in an increased expansion of the chest. If one side of the nose is blocked the same side of the chest does not expand as fully as the other side. In a person who breathes through the mouth the blood is not oxygenated as much as in one who breathes through the nose,