Y. Henderson and H. W. Haggard 339 
closely fitting mask and as the CO, increased oxygen was added 
in equal amount. 
EXPERIMENTAL. 
Two control experiments were performed. They demonstrate 
that under the conditions all the functions remain nearly con- 
stant. Even in the slight variations observed the CO, content 
of the blood shows a tendency to follow the alveolar CO, within 
5 minutes. With a distinct lag of 15 to 30 minutes the CO, 
capacity follows the CO: content. : 
Experiment 1.—Control. Dog, male, 12 kilos. Nodrug. Animal quiet 
and comfortable, and breathing normally throughout. Air used for equi- 
librating blood contained 5.4 per cent COs. 
Blood COz. 
Time. Conditions. Alveolar COsz. ee 
Content. Capacity. 
p.m. per cent vol. per cent vol. per cent 6b: 
4.15 Normal. 5.4 46 47 39.8 
4.45 a 5.5 48 47 39.8 
5.15 a 5.2 4. 45 39.8 
5.45 ut 5.4 00 47 39.7 
6.15 ib 5.2 50 SOG er 107 1639-8 
6.45 af 5.3 48 46 39.8 
7.15 cs 5.4 49 50 39.6 
Experiment 2.—Control. Dog, male, 9 kilos. Conditions as in Ex- 
periment 1. Equilibrating air 5.5 per cent COs. 
Blood CO2. 
Time. Condition. Alveolar CO2.| ——_____ Shade i 
Content. Capacity. 
per cent vol. per cent vol. per cent oe 
10.15 a.m. Normal. 5.3) 47 49 39.7 
10/45 = -* “ 5.2 47 48 39.7 
$1215" * se 5.4 50 48 
14h a" sf 5.1 48 48 39.7 
PGs a 5.5 ol 50 
12.45 “ ot 5.5 51 49 39.8 
1.45 p.m. « 5.4 51 52 
oe a s 5.4 50 50 39.7 
THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL. XXXIII, NO. 2 
