488 



CHEMISTRY OF THE PROTEIDS 



CHAl'. 



Vilh. Maar, who used A. Neumann's method, 1 and the specific oxygen 

 capacity was then calculated from the amount found. The coagulation 

 of blood and bacterial action were prevented by the addition of 

 1 : 1000 potassium oxalate or 2 : 1000 sodium fluoride. 



Arterial blood taken from the arteria maxillaris externa of the 

 horse while it was feeding showed 



Milligrammes of iron in 100 grammes of blood . 31 '75 



Specific weight of blood ..... 1*054 



Specific oxygen capacity ..... 394*000 



Venous blood from the vena maxillaris showed a specific oxygen 



capacity of 387. 



The following Figure represents the differences in the amounts of 

 oxygen which are bound by normal blood, B ; a corresponding hsemo- 

 globin solution and blood plasma, P. 



100 



90 



so 



70 

 60 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 



Curves representing the oxygen capacity of B, normal blood or hsemochrome ; of H, haemoglobin, 

 and of P, plasma. (Combined from Bohr's Article in Nagel's Physiology.) 



The C0 2 Capacity of Blood 



That haemoglobin combines with carbon dioxide has been known 

 for a long time ; but Bohr 2 was the first to point out that C0 2 if under 

 a certain pressure will diminish the oxygen capacity, while the reverse 

 does not hold good. His preliminary observations were, however, 

 inconstant as regards quantitative data, and therefore the whole 

 question was reinvestigated with fresh blood, containing what Bohr 

 calls the genuine blood-colouring matter or haemochrome. 3 He arrived 



1 A. Neumann, Zeitschr. f. physioL Ghem. 87. 115 (1902). 



2 Chr. Bohr, Skand. Arch. f. PhysioL 3. 47 (1892). 



3 Chr. Bohr, Zentralbl. /. PhysioL 17. 682 (1903-1904). 



