RESPIRATION 



41 



The air cannot be entirely forced from the lungs. 

 Even after the most forced expiration some air will still 

 remain in them (Fig. 27). If this air is not frequently 

 and thoroughly changed it will make an excellent 

 medium for the growth of disease germs. Most disease 

 bacteria do not thrive well in the presence of oxygen, but 

 thrive admirably in its absence. People therefore who 

 practice collar bone breathing exclusively are apt to 

 leave the lower part of the lungs unused (Fig. 28). 



ABC 



Fig. 28 — Types of breathing. A, corsetted figure, clavicular or collar bone breath- 

 ing ; B, male figure, abdominal breathing. Pressure of clothing and faulty 

 position impedes expansion of the chest. C, figure properly posed and free 

 from constriction. (After Coleman.) 



They succumb much more easily to tuberculosis than 

 those who breathe deeply. 



Diaphragmatic breathing may be cultivated by sim- 

 ple exercise. Place the hands beside the lower ribs on 

 each side of the body and force the ribs out against the 

 hands. This will enlarge the chest cavity and air will 

 enter. It is not necessary to suck in the air. The lungs 

 are passive. They need not be considered, for they have 



