802 



CHANGE OF COMPOSITION OF ALVEOLAR AIR, 



are shown plotted as ordinates against periods of holding the 

 • c 



r 



breath or of breathing into and out of a bag as abscissa?. 



Text-fig.2. — Variation of logarithms of differences between existing and 

 final alveolar tensions of carbon dioxide and of oxygen (ordinates), 

 with period of holding the breath (A, B), and with period of re- 

 breathing expired air (C, D). Times (abscissae) in seconds. In each 

 curve, the logarithms are plotted to the same scale, but the zero 

 ordinates are adjusted to bring the curves together. 



