486 



CHEMISTRY OF THE PROTEIDS 



CHAP. 



been omitted. Hiifner's tables cannot be used for the direct estimation 

 of the oxygen capacity of blood under varying barometric pressures, 

 according to Schumburg and Zuntz and O. Cohnheim. 1 Loewy and 

 Zuntz 2 showed that the dissociation of oxyhsemoglobin varies accord- 

 ing to the amount of dilution of the haemoglobin, as had previously 

 also been observed by Hiifner and Bohr, and that laked blood behaves- 

 differently from normal opaque blood. The more concentrated a 

 haemoglobin solution the less oxygen does it absorb under equal 

 pressures, and therefore laked blood shows a different behaviour frcro 



0. pressure in 

 mm.Hg. 



/L 



56-88 



3O 4O 5O GO 7O 8O 9O TOO/? 



Percentage Saturation 



A, Loewy and Zuntz (dog's blood) ; B, Loewy (human blood) ; C, Paul Bert ; D, Hiifner's new 

 curve ; E, Hiifner's old curve. 



normal blood because the same quantity of haemoglobin is distributed 

 over, say, twice the volume. Loewy 3 states that this dilution is also 

 the reason why Hiifner's observations, which are based on laked 

 blood, differ from the older observations of Wolffberg and Strassberg 

 made in Pfliiger's laboratory on normal blood, for according to 

 Strassberg 4 haemoglobin is saturated to 60 per cent under an oxygen 

 tension of 25 mm. Hg, while Hiifner found the saturation in his older 



1 Schumburg and N. Zuntz, Pfiiigers Archiv, 63. 461 (1896) ; 0. Cohnheim, 

 Ergebnisse der Physiol. II. 1. 625 ff. (1903). 



2 A. Loewy and N. Zuntz, Arch. f. (Anat. u.) Physiol. 1904, p. 168. 



3 A. Loewy, ibid. p. 565. 



4 G. Strassberg, ibid. 4. 454, and 6. 65 ; Wolffberg, Pfluger's Arch. 4. 465 (1870), 

 and 6. 23 (1872). 



