The dissociation curve of haemoglobin 



21 



You can have any number of rectangular hyperbolae all of which 

 pass through the point A and approximate to OX, such as are 

 shown in Fig. 10: these all satisfy the condition stated above 



n, 100 



The difference between them lies in the value of K. Now Hiifner 

 assumed the correctness of the equation and set out to find the value 

 of K. This can be done from one point. He used a number of 

 samples of haemoglobin prepared in different ways, determined a 

 point for each, found the value of K, averaged these values and 

 produced a curve. But a nemesis awaited Hiifner. His speculations 



80 



70 



60 



30 



20 



10H 



10 20 30 40 50 60 70 80 90 100 



FIG. 11. Dissociation curves of haemoglobin. H according to Hiifuer. 



B according to Bohr. 



fell in the hands of a physiologist of a diametrically opposite school. 

 Bohr (2) had inherited a tradition from the great laboratory of Ludwig 

 which, though it may carry its holders to excessive lengths, at least 

 forms a useful corrective to unjustifiable generalisations. Bohr's 

 motto was that every experiment had a value, nothing which was 

 obtained as the result of a test in the laboratory was set aside on 

 the ground of its inherent unlikelihood, of its failure to fit general 

 principles. Bohr therefore determined to map out the curve relating 

 the pressure of oxygen to the relative quantities of oxy- and reduced 



