360 CO, Capacity of Blood. III - 
Experiment 4 affords evidence that excessive ventilation may 
have profound effects, including circulatory failure, which may 
continue even when the CO, capacity returns to normal,—unless 
perhaps this ‘animal was unusually susceptible to chloratone. 
Death was evidently due to circulatory failure. 
Experiment 4.—Dog, male, 9 kilos. Overventilation. Similar to Experi- 
ment 3. Equilibrating air 5.5 per cent CQ). 
Blood CO:. 
Time. Condition. et | A ptorinl 
Content. | Capacity. Pipes 
vol. vol. 
per cent | per cent ret: 
9.00 a.m. Normal. 47 00 : 
O02. Chloratone, 1.8 gm. 
O20 ax oo) 48 100 
10-504: Ventilation started. 
10.50 “ 29 42 70 
11.200 4 21 37 70 
11.50% 34 | 40 60 
12.20 fa Reflexes hyperactive. 
12,204 33 36 60 
1.45 p.m. Ventilation stopped. 
Tes ae 30 38 60 
OLD as ae 43 a4 58 
2ia0— Oxygen lack. Blood dark. 
Occasional gasps. 
Syl5\ ** Reflexes sluggish. 43 44 50 
S40“ Irregular blood pressure. 50-90 
4.00 “ Great O2 deficiency. 60 54 30 
2A 0,1 Dog dead. 
Autopsy.—Nothing abnormal found. 
From the two preceding experiments it is clear that excessive 
artificial respiration results in a marked decrease in the CO, 
content and CO: capacity of the blood and also in the arterial 
pressure. In the light of the experiments reported in the two 
preceding papers of this series it is altogether likely that these 
results are chiefly due to the excessive ventilation. A possible 
objection may however be made that the violent movements of 
excessive artificial respiration are in part responsible for the effects, 
