BLOOD, RESPIRATION, CIRCULATION AND DISTURBANCES 309 



Since BONDER'S time it has been assumed, therefore, that a disso- 

 ciation occurs much as in the case of calcium carbonate which is 

 dissociated into CaO and CO 2 at high temperatures; the degree of 

 dissociation is dependent upon the C0 2 pressure. CHR. BOHR es- 

 pecially followed up this idea and on the basis of rather complicated 

 premises reached an approximate agreement between theoretical 

 and experimental values. H. W. FISCHER and E. BRIEGER think 

 that iron exists in hemoglobin " protected " by the organic complex. 

 In alkaline solution it occurs as a ferrate, i.e., a superoxid (analogous 

 to manganate), but in a solution made acid by CO 2 it is unstable and 

 parts with oxygen. Another explanation offered by the assumption 

 of Wo. OSTWALD * 3 is that the taking up and release of or C0 2 

 by hemoglobin and blood is an adsorption. He compares the process 

 to the absorption of gases by charcoal, spongy platinum, etc. In 

 both cases there exists a reversible balance, in both cases one gas 

 may be replaced by the other (O by CO 2 and vice versa). The curves 

 obtained in the adsorption of O or C0 2 by hemoglobin or blood in 

 the presence of increasing gas pressures correspond to the recog- 

 nized adsorption curves. On comparing the differences between 

 theory and experiment in the case of BOHR'S dissociation formula, 

 on the one hand, and Wo. OSTWALD'S adsorption formula, on the. 

 other, it is evident that for the latter they are much smaller. 



Hitherto we have spoken of the adsorption of O and C0 2 by 

 hemoglobin, blood corpuscles and blood as identical, but in reality the 

 phenomena in the blood are very complicated. 



The absorption and the release of oxygen by hemoglobin may be 

 considered a relatively simple phenomenon. But even in the case of 

 blood corpuscles and blood, observation and calculation do not agree 

 so well. Wo. OSTWALD says (loc. cit., p. 296), "These variations are 

 characterized by the fact that in the case of low oxygen pressures 

 (somewhat below 25 mm. Hg) the observed oxygen absorption is con- 

 siderably less than would be expected in accordance with the adsorp- 

 tion formula. " In my opinion this variation is sufficiently explained if 

 we consider the lipoids of blood corpuscles; O is more soluble in them 

 than in water and there is no objection to the assumption that the 

 distribution in the lipoids with changing gas pressure follows Henry's 

 law. Under these circumstances the curve of oxygen absorption in 

 the blood must waver between that of the adsorption curve and the 

 straight line of distribution in accordance with Henry's law. By 

 observation of the curve elaborated by Wo. OSTWALD (in accordance 

 with A. LOEWY), I find this view substantiated (loc. cit., p. 297). 



The absorption and release of CO 2 by the blood and blood corpus- 

 cles is further complicated by the blood salts. By their presence the 



