132 Determination of Oxygen in Blood 
ment of the gasometric with the colorimetric determination of 
hemoglobin® by the most accurate use of the colorimetric tech- 
nique. It consequently appears unnecessary to reproduce in 
this paper further data to illustrate the results obtained with the 
method. 
SUMMARY. 
The apparatus previously described for determination of car- 
bon dioxide in blood is used with a similar technique for deter- 
mination of oxygen. The oxygen is set free from combination 
with hemoglobin within the apparatus by addition of ferricyanide, 
is extracted in a Toricellian vacuum, and measured at atmospheric 
pressure, a few minutes sufficing for an accurate determination. 
6 Palmer, W. W., J. Biol. Chem., 1918, xxxiii, 119. 
