quantity of organic matter are exhaled, the latter dependent upon the condition of the digestive apparatus.
In order to supply oxygen to the system, from 300 to 400 cubic feet of air are drawn into the lungs in twenty-four hours. Each hour an adult inhales about 500 grains of oxygen and emits about 600 grains of carbonic acid with a much larger amount of watery vapor. Deprived of air the body perishes from asphyxiation.
It follows that not only is a continued supply of fresh air essential to life, but that constant care is necessary to insure its purity at the moment of delivery. The natural channels for the passage of air to the lungs begin at the nostrils, which are furnished with short fine hairs and with mucus secretion, mechanical preventives of the inhalation of dust and light material. If obstruction of the nasal tract occurs, it is possible for breathing to take place through the mouth, but so harmful is the latter method to general health that attention is here directed to its results.
Overfeeding a child invariably develops a cold with accompanying nasal discharge and consequent obstruction of the natural air
