362 CO, Capacity of Blood. III 
Experiment 5.—Control experiment. Dog, male, 9 kilos. Excessive 
artificial respiration with air containing CO,. Equilibrating air 5.5 per 
cent CO». 
Blood COs. 
Time. Condition. hind see 
Content. | Capacity. 
p.m. vol. per cent) vol. per cent mm. 
2.10 Normal. 47 49 
2.30 Chloratone, 1.8 gm. 
3.00 Ether. Operated. 
IM | ‘< stopped. 43 46 
3.40 110 
3.45 Ventilation started. 
3.50 138 
4.15 56 a2 
4.40 | Contents of rebreathing chamber 
7.9 per cent COs. 
4.45 58 53 
4.45 142 
5.10 | Contents of rebreathing chamber 
6.7 per cent COs. 
DAD 56 54 126 
5:22 Ventilation stopped. 
5.45 Respirations, 32 per min. } 118 
5.55 38 44 90 
6.15 Respirations, 37 per min. 75 
6.30 - va oe 80 
Reflexes normal, animal in good condition. Killed. 
From this experiment it appears that the movements of exces- 
sive artificial respiration so far from causing a fall of arterial 
pressure in themselves tend to cause (or at least are compatible 
with) a rise, due either to the pumping action upon the thoracic 
and abdominal blood vessels or to the effects of high CO,. The 
rather low arterial pressure after termination of the period of 
excessive ventilation may fairly be assigned to the chloratone. 
CONCLUSIONS. 
Excessive pulmonary ventilation by means of artificial respira- 
tion induces not only a lowering of the CO. content but also of the 
CO. capacity of the blood. Arterial pressure also falls and death 
