READJUSTMENTS OF REGULATION 33 
o-T | 
too. 
\ 
\ 
ie 
LTA 
\K\ 
en 
BSN 
ff 
10 20 30 . 40 50 60 70 80 90 100 110 120 
measure of CO, im mun. deg. 
Fic. 2. Lower curve—absorption of COz by blood in pres- 
ence of air and COz. Upper curve—absorption of COz 
by blood in presence of hydrogen and COz. The line 
A-B represents the absorption of CO2 within the body. 
therefore represented by the thick line starting at 40 
mm. which is the pressure of CO, in arterial blood. 
This line rises steeply, so that far more CO, can be 
taken up by the blood with a given rise of CO, pres- 
sure than would be the case if oxyhaemoglobin and 
reduced haemoglobin had the same effect on the ab- 
sorption of CO,. It follows also that when the venous 
blood reaches the lungs and suddenly becomes oxy- 
genated, the pressure of CO, in the blood suddenly 
rises. In this way much more CO, is given off than 
would otherwise be the case considering the existing 
