THE DISSOCIATION CURVE OF HEMOGLOBIN 113 



the manner of CO, but that its action is indirect by producing 

 a change in the hydrogen-ion concentration of the fluid, the further 

 question must be asked: In virtue of what mechanism does an 

 increase of the hydrogen-ion concentration of the haemoglobin solution 

 weaken the bond between haemoglobin and oxygen, and alternatively, 



lOOr 



Fig. 36. Dissociation curves of CO-hsemoglobin. Curves drawn from formula 



^' 1 + Kx» 



The curve is based on the coincidence of point A with the corresponding point 

 on Fig. 35. 



Ordinate = percentage saturation with CO. 



Abscissa = CO pressure in mm. Points indicated are the determinations of Haldane 

 and Douglas. 



by what process does a reduction in hydrogen-ion concentration 

 strengthen the bond between oxygen and haemoglobin? 



This enquiry has been pursued by A. V. Hill(i3), (14), (15) and his 

 colleagues, and also by L. J. Henderson (16), (17) on the theoretical side, 



