182 



Scientific Proceedings (108). 



two thirds of the shift of base, and since other anions, chiefly 

 HC0 3 ' but also S0 4 ", shift in the same direction as CI', it seems 

 improbable that there is any considerable migration of kations in 

 and out of the cells, with the exception of hydrogen ions. This 

 is in accord with the older ideas on this subject. We are at 

 present investigating also the extent of migration of HC0 3 ' ions. 



As a general conclusion it may be stated that when the hetero- 

 geneous acid-base equilibrium is disturbed, from any cause, the 

 new equilibrium is established by the migration of acids in and 

 out of the cells, and that about two thirds of this acid is hydro- 

 chloric acid. 



Further confirmation of the mechanism of the chloride shift is 

 obtained from the fact that the shift is produced by varying the 

 tension of oxygen as well as by varying the tension of carbon 

 dioxide. The fact that the chloride shift occurs isohydrically 

 provides additional evidence as to the change in the acidity of 

 hemoglobin at varying tensions of oxygen. 



In all of our experiments we have obtained data pointing to an 

 extremely constant relationship between the various factors 

 studied — i.e., hemoglobin, oxygen, carbon dioxide, bicarbonate, 

 chlorides, and hydrogen ion concentration — for different samples 

 of ox blood. We are proceeding with the investigation in the hope 

 of reducing these relationships to precise mathematical form. 



W T e have obtained evidence to the effect that the buffer action 

 of the serum under physiological conditions as compared with 

 isolated serum is increased at least ten times by the change in 

 acidity of hemoglobin. 



It should be noted that we have studied the hydrogen ion 

 concentration on the alkaline side of the isoelectric points of hemo- 

 globin and serum proteins. At these hydrogen concentrations, 

 as has been shown by Loeb, 1 the amphoteric colloids dissociate 

 entirely, or almost entirely, as acids, so that we have disregarded, 

 for the present, the possibility of combination of chloride and 

 other anions with the colloid substances present. 



Jacques Loeb, "Emphotcric colloids. I. Chemical influence of the hydrogen 

 ion concentration," J. General Physiol., 1918, I, 39. 



