RESPIRATION 267 



Metabolism (by Douglas Bag method) = 330 cc. of CO 2 and 379 

 cc. of oxygen (at o and 760 mm.) per minute. 



As the venous CO 2 pressure was 6.O mm. above the arterial, 

 the blood (calculating from Figure 26) had gained 4.2 per cent 

 by volume of CO 2 . Hence the circulation rate calculated from CO 2 



was - = 7.9 liters per minute. As the venous oxygen pressure 



was 44.5 mm. and this corresponds, calculating from Figure 28, 

 to 73 per cent saturation of the haemoglobin, the blood had lost 

 about 22 per cent of its combined oxygen. Adding the correspond- 

 ing small amount of dissolved oxygen this corresponds to a loss 

 of about 4.3 volumes per cent of oxygen. Hence the circulation 



rate, calculating from the oxygen, was - = 8.8 liters per 



43 

 minute. 



No. 2. 27/2/1$. Bar. 752 mm. 



Mixture used contained 6.26 per cent of CO 2 and 5.26 per cent of 



oxygen. 

 First alveolar sample 2" after last deep inspiration, CO 2 = 6.26 



per cent and O 2 = 6.25 per cent. 

 Second alveolar sample 5" after first sample, CO 2 = 6.30, O 2 = 



6.09 per cent. 

 Therefore venous CO 2 pressure = 6.30 per cent = 44.4 mm. ; and 



oxygen pressure 6.09 per cent = 42.9 mm. 



Normal alveolar CO 2 pressure (mean) = 5.55 per cent = 39.1 mm. 

 Metabolism 332 cc. of CO 2 and 374 cc. of oxygen absorbed (at o 



and 760 mm.) per minute. 



As the venous CO 2 pressure was 5.3 mm. above the arterial, the 

 blood (calculating from Figure 26) had gained 3.7 volumes per 

 cent of CO 2 . Hence the circulation rate calculated from CO 2 was 



- = 9.0 liters per minute. As the venous oxygen pressure was 

 o / 



42.9 mm., and this corresponds (Figure 28) to 70 per cent satura- 

 tion of the haemoglobin, the blood had lost about 25 per cent of 

 combined oxygen or about 4.9 volumes per cent of oxygen. Hence 



the circulation rate, calculating from the oxygen, was = g.o 



47 

 liters per minute. 



If we take these two experiments together, the circulation rate 

 determined from the CO 2 was 8.45 liters per minute, and from 



