102 



PHYSIOLOGY. 



IN 10,000 VOLUMES. 



i Represented by Largo Square.) 



PER CENT. 



AMOUNT OF CARBON 



DIOXID. 



IN 



INSPIRED AIR. EXPIRED AIR. 



4 400 



(Small Square.) (Medium Square). 



.04 4 



COMMON FRACTION ^~ 



r 



25 



20 100 



Fig. 45. Amount of Carbon Dioxid in Inspired and Expired Air. 



The Composition of Inspired and Expired Air. - 



Oxygen. Nitrogen. Carbon Dioxid. 

 Inspired air ... 21 79 .04 



Expired air ... 16 79 4.00 



While the amount of nitrogen remains about the same, 

 some oxygen has disappeared, and its place is taken by 

 carbon dioxid, while the amount of carbon dioxid has in- 

 creased a hundred-fold. 



