398 CO, Capacity of Blood. III 
In Experiment 2 the artificial respiration was made as vigorous 
as possible. The instant the lungs were filled or emptied the 
lever was reversed and the alternate phase of respiration induced. 
From the protocol it appears that within 22 minutes the CO: 
content of the blood was reduced from 52 to 22, the CO» capacity 
from 50 to 388, and the arterial pressure from 130 mm. down to 50. 
When the ventilation was stopped it was necessary to administer 
artificial respiration by hand by squeezing the chest occasionally 
in order to prevent death from prolonged apnea. Even so, all 
of the functions measured continued to fall, the CO. capacity to 
28 and arterial pressure to 25, and the animal died 55 minutes 
after the artificial respiration was stopped. In all of these. ex- 
periments a careful autopsy was conducted, air embolism and 
pulmonary hemorrhages being particularly looked for. The find- 
ings in this respect were negative. In this animal the only ab- 
normality found was a mass of roundworms in the right heart. 
Experiment 2.—Dog, male, 8 kilos. Passive overventilation. Equili- 
brating air 5.6 per cent CQ». 
Blood: COs. 
Time. Condition. i Reis, 
Content. | Capacity. 
vee Ee: ay 
10.15 a.m. Normal. 53 ol 
10.30. “ Chloratone, 2 gm. 
P1255 7° Operated. 52 50 130 
11.48 “ Ventilation started. 
TOO Doe 110 
11.55 “ 50 
12:05nen Ventilation stopped. | \ 
12.06 “ i 92 38 : 
12,20 Reflexes hyperactive. , 25 
12.30. 4% 20 28 25 
12/35 9a Reflexes practically absent. 
Respirations 36 per min. 
1.00 p.m. Dead. 
In Experiment 3 the artificial respiration was carried on much 
less vigorously than in the preceding case, but was still mark- 
edly in excess of normal breathing. In the course of an hour and 
