212 Scientific Proceedings (108). 



into a fixed volume of air, a portion of which is analyzed directly 

 for oxygen by absorption with alkaline pyrogallate. After applica- 

 tion of all the corrections suggested by the authors of these 

 methods, the results are not identical, — analyses by the Van 

 Slyke method yielding 4 to 10 volumes per cent, more oxygen 

 than those by the Henderson-Smith method. The divergence 

 between the results from each method may represent a variation 

 of 17 to 64 per cent. A few typical figures are cited in Table I. 



table I. 



Sample. 



Van Slyke 

 Vol. Per 

 Cent. 0 2 . 



Henderson- 

 Smith Vol. 

 Per Cent. 0 2 . 



Difference. 

 Amount. Per Cent. 





12.9 



IO.4 



2-5 



19.4 





18.5 



12.8 



5-7 



30.8 





20.1 



I4.6 



5-5 



27.4 





20.0 



15-5 



4-5 



22.6 



It is clear that there is a constant factor or factors at play, 

 inherent in the methods of analysis employed, which ought to 

 account for this discrepancy. 



The gas evacuated by the Van Slyke procedure is not all 

 oxygen but probably contains in addition to nitrogen, minute 

 amounts of carbon monoxide, hydrogen, methane and the rare 

 atmospheric gases. Bohr 1 states that blood contains 1.23 volumes 

 per cent, of nitrogen (incorrectly quoted by Van Slyke as 0.9 vol. 

 per cent.) and 0.22 volumes per cent, of the other gases — a total 

 of about 1.45 volumes per cent, of gas not oxygen. We have 

 absorbed with alkaline pyrogallate, the oxygen from the gas 

 extracted in the Van Slyke procedure and have found in all cases a 

 residue of 0.055 to 0.082 c.c. from 2 c.c. of blood — an average of 

 about 3.3 volumes per cent. This residue does not contain CO2, 

 and we have reason to believe that it is practically all nitrogen. 

 It occurs to the same extent in aerated blood as in venous. Since 

 this residue is almost constant within narrow limits, its value may 

 be subtracted from the total Van Slyke gas volume as an average 

 correction. We have applied this correction in Table II, and 

 have thereby reduced the level of the Van Slyke figures by about 

 two volumes per cent. A further refinement would be to deduct 



1 Bohr, C, in Nagel, W., "Handb. Physiol, d. Mensch.," 1909, I, 117. 



