114 



HEMOGLOBIN 



and against it has been directed the whole artillery of the Rockefeller 

 Institute by Dr Van Slyke(i8), (19), (20). 



There seems to be general agreement on one point, namely, that 

 the key of the situation lies in the fact of oxyhaemoglobin being 

 a stronger acid than reduced haemoglobin. This has been shown to 

 be the case by Parsons (2i), who made actual hydrogen-ion measure- 

 ments of oxygenated and reduced blood under similar conditions and 

 found that the fact of oxygenating the blood (or alternatively treating 

 it with carbon monoxide) increased the hydrogen-ion concentration 

 by about 8 per cent. Imagine then a solution containing reduced 

 haemoglobin, CO2 and Na ; some of the Na will be united with the COg 

 and some with the haemoglobin. Some such crude scheme as the 

 following may be pictured: 



COi 



/n As Sodium 



Solufion Arcarifonate 



//aemo^/obm 



^/4s Sodium. 

 I . /laemo^lohznafe //h-acid 



As 



\ As Sodium 6rcar6ona/k ' ' Sodtum ! 



Haemo^lo6tn (Oxy) 



7,- ^;_^Av ^" ►- '^^ Sodium ^ Y A5 Sodium As /ret , 



' As Sodium 



ir 



As Sodrum oxy^aemo 

 />rearji>o/Ta/e -£iohina/e 



Sodea?n 



Fio. 37. 



The CO2 is present in two forms, partly in solution and partly united 

 with the sodium. The reduced haemoglobin similarly is present partly 

 as the free acid and partly as the sodium salt ; thus a certain quantity 

 of sodium is united with the COg and a certain quantity with the 

 reduced haemoglobin. These facts are indicated^in the upper scheme. 

 Suppose now that the reduced haemoglobin becomes oxidised, the 

 sodium will, so to speak, be pulled in the direction of the haemoglobin, 

 and therefore less sodium will rniite with the COg , a greater quantity 

 of CO2 will go into solution and, if the solution had previously been 



