Donald D. Van Slyke 131 
although the error must be greater in the latter case because of 
the small volumes of gas obtained for the final reading. 
TABLE II. 
Determinations of the Oxygen Capacity of Ox Blood, Using 1 to 3 Cc. Samples. 
Per cent hemo- 
Volume of Oz I 
reduced to globin, caleu- 
Volumect | Toinpers-| Barome- | Cee, YO] Gas, solvme | GR Teo) mim. | lated x bane 
sample. tained. dissolved air. 460) ce. of cent Oz = 100 
beep piace eeeahe 
PPR sear is) Cite (+ hh, ey ita cc. ee gd aey per cent 
3.00 20 752 0.835 0.784 23.45 26.7 
2.00 20 752 0.558 0.524 23.49 —~ 126.9 
1.00 20 752 0.281 0.264 28.67 127.9 
For determination of the oxygen content of the venous blood 
as drawn from the body,.the preliminary saturation with air is 
omitted, and precautions, such as are described by Lundsgaard 
in the accompanying paper,* are observed in order to prevent 
contact of the sample with air. From the point where the blood 
sample is transferred to the cup of the apparatus for analysis 
the technique is identical with that described above. 
The calculation of the oxygen content is somewhat different 
from that of the oxygen capacity. The physically dissolved oxy- 
gen of venous blood is negligible, and thenitrogenas determined 
by Bohr is 0.9 volume per cent, reduced to 0°, 760mm.° There- 
fore the volume of gas obtained in the apparatus is at once mul- 
tiplied by the factor (0.999 — 0.0046 ¢) x panne to reduce 
it to standard conditions. In case 2 ce. of blood have been used, — 
the values of this factor in Column 3 of Table I may be used; in 
this case they give the content of the blood in chemically bound 
oxygen plus the dissolved nitrogen gas. The result in cc. of gas 
per 100 ce. of blood is diminished by 0.9 cc. in order to cor- 
rect for that amount of nitrogen gas present. 
The nature of the results obtained with the method and the 
degree of accuracy indicated by the agreement of duplicates are 
shown by Lundsgaard’s figures,* while Palmer’s show the agree- 
4 Lundsgaard, C., J. Biol. Chem., 1918, xxxiii, 133. 
5 Bohr, C., in Nagel, W., Handb. Physiol. Menschen, 1909, i, 117. 
