CHAPTER XVII 



HOW EXERCISE MAY IMPROVE JACK'S HOUSE 



BUT what about forming the habit of rhythmic deep 

 breathing? Suppose we are breathing through the 

 nose and also keeping our mouths shut except when 

 talking and eating, w r hat is the next 

 step ? Our aim is to take into our 

 bodies the largest possible amount of 

 air with the least possible effort. We 

 know that the larger the chest cavity 

 is made, the greater the expansion 

 of the lungs will be, and hence the 

 larger the amount of air that will 

 rush in to fill the space. We have 

 already learned that the greatest en- 

 largement of the chest cavity is made 

 by simultaneous movements of the 

 diaphragm and the intercostal mus- 



C*\ C*Q 



Improper position; 



causes spine to curve Now in order to get the best and 



to side ; raises one hip . , 



and shoulder above most natural movement ot these 

 the other. muscles, the spine must be in an erect 



position with the shoulders well back, the chest in- 

 clined outward, and the abdomen inward. The head 



158 



