CARE OF THE ORGANS OF RESPIRATION 387 



surest way to keep the organs of respiration in good health 

 is to learn good methods of breathing, and to breathe 

 good air (review 246 to 249). Our breathing should be 

 "full," and not "shallow"; that is, it should give all the 

 lung cells opportunity to carry on the exchange of gases, 

 and not only a part of them. It is the unused portions 

 of the lungs that are most liable to disease. We should 

 stand and sit erect, with shoulders thrown back, and the 

 chest expanded, at every inspiration. If we are confined 

 indoors because of our work, we should go out of doors, 

 or to an open window, every little while, and should 

 breathe deeply of fresh air. 



We should all breathe through the nostrils, and not 

 through the mouth. The nostrils remove dust and the 

 disease germs that cling to it (c/. 387), while mouth- 

 breathing permits the germ-covered dust to enter the 

 throat, windpipe, and lungs. Mouth-breathers are espe- 

 cially likely to have throat and lung diseases. Some 

 children have growths in the nasal passages (" nasal 

 polyps") or in the pharynx ("adenoids"); these close 

 the nasal openings to the lungs, and cause mouth-breath- 

 ing. All such growths should be removed by a competent 

 surgeon, for they often bring on, not only throat and lung 

 diseases, but also deafness ; and they make many a child 

 appear stupid, when he is really ill. 



Colds require the greatest care, for they lower the power of the 

 body, especially of the organs of respiration, to resist disease, and make 

 these organs fall an easy prey to pneumonia, consumption, diphtheria, 

 etc. The practice of deep breathing is a great aid in preventing colds. 



Tobacco smoke irritates the throat and lungs by clogging up their 

 delicate membranes with soot. Cigarettes, especially, are harmful 



