THE DISSOCIATION CURVE OF HEMOGLOBIN 



97 



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 generaUsations. 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 or 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 haemoglobin 

 point by point, irrespective of laws, and to find out experimentally 

 what it actually was like. 



Fig. 26. Dissociation curves of haemoglobin. H according to Hiifner. 

 B according to Bohr. 



Fig. 26 represents the curves of Bohr and Hiifner respectively; it 

 shows that the actual curve differs fundamentally from Hiifner's, not 

 only in the fact that it crosses it and therefore cannot be a hyperbola 

 but that it has a double contour and consequently is not a curve of 

 the same order at all. 



At the present time it is scarcely necessary to dwell on the theory 

 which Bohr propounded to explain his curve, quite briefly it was 

 that when oxygen broke from haemoglobin, the haemoglobin itself 

 split into globin and something rather like haematin which he 

 called haemochrome. Another explanation of this curve will be 



