THE RESPIRATION 8 1 



by children of all races, by both men and women of wild 

 tribes, and by men of civilized countries. It is undoubtedly 

 the natural way, as well as the easiest and most effective 

 way (Exps. 16, 17, 18). 



Breathing with the upper chest is exhausting because of the stiffness 

 of the upper part of the bony cage (see Fig. 75) ; for it is inclosed by 

 true ribs fixed to the breastbone by short cartilages. The ribs in the 

 waist (Fig. 75) are either floating in front or fixed by long cartilages to 

 the ribs above. In pure abdominal breathing the diaphragm must con- 

 tract more than in full breathing in order to descend, because its edges 

 have been drawn together and fixed by binding the ribs at the waist. 

 In full breathing the floating and false ribs at the waist (five pairs in 

 all) float in and out as nature provided. As they move out, this 

 broadens and deepens the chest, and aids the flattening of the dia- 

 phragm by moving its edges farther apart. Those persons, perhaps 

 one in a thousand, who voluntarily deform the body with tight clothing 

 are beneath contempt. But so uniform is the pressure of tight clothes 

 and shoes that the wearer soon becomes unconscious of them, and so 

 powerful are the effects that not one person in a thousand escapes 

 deformity and injury. Children's clothing should be supported by the 

 shoulders, and adults' clothing by both shoulders and hips, but by 

 the waist, never. 



Cellular Respiration. — The chemical activities within the cells and 

 their need of oxygen, not the amount of oxygen in the lungs or blood, 

 determine how much oxygen the cells absorb from the blood. Oxygen 

 cannot be forced even into the blood beyond the required amount. 

 Deep breathing movements, however, help the flow of the blood and 

 lymph. Carried to excess, they tire the will and exhaust the nerves. 



Changes in Blood while in the Lungs. — The coloring 

 matter (or hemoglobin) of the corpuscles absorbs oxygen 

 (and becomes oxy-hemoglobin). Carbon dioxid is given off 

 from the plasma. The blood becomes a brighter red. 



Changes in Air in the Lungs. — The air entering the 

 lungs consists of about one fifth oxygen and four fifths 

 nitrogen. This nitrogen is of no use to the body, and is 

 exhaled unchanged. A part of the oxygen inspired is taken 

 up by the blood, and carbon dioxid is sent out in its place. 



