Y. Henderson and H. W. Haggard 308 
CONCLUSIONS. 
The disturbance of the CO, capacity of the blood by ether ap- 
pears from these experiments to be wholly dependent on disturb- 
ance of respiration. If the anesthesia is managed so that respi- 
ration is but little increased, the lowering of the CO: capacity 
of the blood is slight. Ether hyperpnea however causes a very 
great reduction. Down to the critical level between 33 and 36 
volumes per cent the process is spontaneously reversible and the 
animal recovers. Below this level it appears to be irreversible, 
and death ensues. 
At present such effects even above the critical level are gener- 
ally interpreted as ‘‘acidosis.”” Our results show them to be of a 
very different origin. It is possible however that below the 
critical level a true acidosis of an asphyxial character sets in. 
Etherization so profound as to depress respiration causes a 
rise of the CO, capacity. 
Light etherization such as is otherwise most effective in low- 
ering the CO, capacity, and most harmful to the subject, loses 
this influence when administered with sufficient CO. to main- 
tain the alveolar CO, at a normal level. | 
From these facts it is clear that under ether the CO, capacity 
of the blood (alkaline reserve) follows and is controlled by the 
CO, content, and that the CO, content is in turn dependent upon 
the alveolar COs, which is determined by the breathing. 
These results afford, we believe, final proof of the essential 
correctness of the views on this topic (acapnia under anesthesia’) 
which have been advocated now for 10 years past in papers from 
this laboratory. 
We desire to acknowledge our debt to Van Slyke and his col- 
laborators‘ for bringing forward the conception of the “alkaline 
reserve,” or as we prefer to call it the CO, capacity of the blood. 
This conception has enabled us to produce proof on a topic 
which after controversy and general rejection was evidently 
passing into oblivion. 
’ Bryant, J., and Henderson, Y., J. Am. Med. Assn., 1915, Ixv, 1 (dis- 
cussion of clinical aspects of problem and references to previous work). 
4-Van Slyke, D. D., Stillman, E., and Cullen, G. E., J. Biol. Chem., 
1917, xxx, 401. 
