r. 



Percentage saturation 

 with oxygen 



10 20 30 40 50 QO 70 80 90 100 



Oxygen pressure 



Fig. 137. Upper left hand, percentage saturation of hemoglobin with oxygen at 37" C. cor- 

 responding to oxygen pressures of 0, 10, 20, 40 and 100 mm. of oxygen, respectively. 



Upper right hand, the same spaced with the oxygen pressure as the abscissae. 



Lower figure, dissociation curve representing the equilibrium between oxygen, oxyhemoglobin 

 (red) and reduced hemoglobin (purple). (From Joseph Barcroft.) 



