Effect of alkali 



45 



which Hiifner himself appears to have been oblivious, but which were, 

 at the time of which we were speaking, only too evident in our own 

 experiments. It seems certain that Hiifner's solutions of haemo- 

 globin, which he regarded as identical, must have differed from one 

 another in their affinities for oxygen as much, if not more, than 

 our own. 



To get the maximum amount of haemoglobin into solution w r e 

 found it advisable to add a little ammonium carbonate ; but we were 

 always assailed with the same result, namely, that no two solutions 

 gave identical dissociation curves. 



% 1 00 



80 



60 



40 



20 







7 



20 40 60 80 100mm. 



FIG. 23. Comparison of points on haemoglobin solution prepared by Bohr's method, 

 with Bohr's dissociation curve. Oxygen pressure horizontal. Percentage saturation 

 vertical. 



One afternoon Camis, Hill and myself, over the laboratory tea, 

 fell to discussing a subject which had frequently been discussed 

 before, namely Bohr's haemochrome theory. We had long since given 

 up any attempt to harmonise our curves with those of others, but 

 the question in our mind was whether with different constants the 

 most recent curve which we had obtained could be made to agree 

 with the general mathematical expression of the theory. Camis read 

 out the positions of the points. 



Tension of oxygen 12-5 15 -5 31 45 72 



Percentage saturation... 29 40 66 77 - 5 90-5 



