186 



Chapter XII 



Haldane and Lorrain Smith exposed haemoglobin to mixtures 

 containing varying known concentrations of oxygen and carbon 

 monoxide, and determined the relative amounts of CO and 2 haemo- 

 globin. In practice the process is somewhat simplified by the fact that 

 if as much as '1 / CO and that is more than would be desirable for 

 the experiment be mixed with air, there is but a negligible diminution 

 in the partial pressure of oxygen. We may conveniently make up 

 mixtures of CO in air assuming that the oxygen is 21 / in each 



100 

 90 

 80 

 70 

 60 

 50 

 40 

 30 



10 



7 



05 



-15 



20 



25 



30 



35 



40 



45 



50 



. 97. Curve of Haldane and Lorrain Smith indicating the partition of haemoglobin 

 between oxygen and CO. Ordinate = percentage of the total haemoglobin present as 

 CO haemoglobin, the remainder being oxyhaemoglobin. Abscissa = percentage of CO 



in air. 



case shake them with haemoglobin solution, and when equilibrium 

 is established analyse the air for CO and the blood for the relative 

 amounts of the two pigments. Plotting such a result, Haldane and 

 Lorrain Smith obtained the above curve, which relates the relative 

 quantities of COHb and 2 Hb to the relative pressures of CO and 

 oxygen gas. 



We have now at our disposal, in theory at all events, the data 

 for carrying out one of Haldane and Lorrain Smith's experiments 

 (we quote their own figures). 



