Relation of temperature to dissociation 



29 



As soon as we have grasped this a whole world of facts is 

 before us. 



Firstly then we must have a different hyperbola for every different 

 temperature. The one we have obtained is not a general expression 

 of the relationship of oxygen to haemoglobin, it is merely the relation- 

 ship at the particular temperature at which we chanced to do our 

 experiments, namely 38 C. Therefore the law of mass action has 

 become doubly exacting. Not only must the dissociation curve be 

 a certain shape, but it must be that shape at all temperatures, and 

 moreover the curves at all temperatures must be related according 



FIG. 14. 



to a certain law. Have we the means by which to test the truth 

 of the chemical conception in the light of these exacting require- 

 ments? Of the quantities in the above formula we have already 

 a value of KI corresponding to the temperature T 1} viz. 38 C. One 

 could determine the value of K 2 for some other temperature T. 2 , and 

 then if only q were known one would have all the data for testing 

 whether K. 2 as calculated was the same as that which was obtained by 

 experiment. But the truth is that we do not know q, or rather we 

 did not when the problem first attracted the attention of Hill (2) ; 

 it was therefore impossible to attack it in just this way. But though 

 it was impossible to make this test, it was possible to do something 



