Y. Henderson and H. W. Haggard ool 
Experiment 6.—Dog, male, 9 kilos. Profound etherization and de- 
pressed respiration. Equilibrating air 5.5 per cent CO». 
Blood COsz. 
Time. Condition. Respirations per min. |————- 
Con- | Capac- 
tent. ity. 
‘vol. l. 
de pica Neen 
3.30 | Normal. 16 52 50 
3.45| Ether started, pushed rapidly. 
4.15 11 60 54 
4.30; Shallow respirations. Blood dark. 16 57 06 
4.45 a a S - 22 57 55 
a 3 a “ CPA tel tical Fe 60 | 61 
5.20| Breathing stopped. Dog dead. 
Experiment 7.—Dog, male, 7 kilos. Similar to Experiment 6. Equili- 
brating air 5.6 per cent CO». 
Blood COs. 
Time. Condition. Respirations per min. 
Con- | Capac- 
tent. 1ty. 
VER an Hoe 
6.10 | Normal. 21 47 47 
6.30| Ether started. Administered 
rapidly. 
7.00 | Respirations very shallow. 72, blood dark. | 64 63 
7.05 | Ether lightened. 
7.30 | Shallow respirations. ose ss 59 60 
7.45 “i 4 | | 40s an as 60 
7.50 | Dog in critical condition. Ether stopped. 
7.52 | Three or four more breaths, then breathing stopped, heart beating. 
7.56 | Heart stopped. Dog dead. 
Even Experiments.6 and 7, decisive as they appear in contrast 
to those preceding them, e.g., Nos. 2, 3, 4, and 5, might leave 
open the possibility that the excitement of light ether causes 
a depression of the CO, capacity in some way (e.g., excessive 
adrenal secretion) other than by the blowing off of CO:. Accord-, 
ingly we performed Experiments 8 and 9 in which light etheriza- 
tion was maintained for several hours but loss of COs was pre- 
vented by the fact that the air which the animal breathed was 
enriched by the addition of CO, in the amounts shown in the 
protocols. It will be seen that in both cases the CO: capacity 
