Y. Henderson and H. W. Haggard ay al 
CONCLUSIONS. 
In reports from Cannon on his observations upon shock in 
wounded soldiers, emphasis has been placed upon the lowering 
of the alkaline reserve of the blood, upon the fact that under 
anesthesia and operation a further lowering occurs, and that 
intravenous injection of alkaline solution has strikingly beneficial 
effects. 
Our experiments show that apart from overventilation of the 
lungs trauma does not cause a lowering of the CO, capacity (alka- 
line reserve) of the blood, even when by general traumatization 
and cooling of the abdominal viscera and consequent stagna- 
tion of the blood in the injured parts, failure of the circulation and 
death are induced. | 
If, on the other hand, no measures are taken to prevent exces- 
sive pulmonary ventilation, the overbreathing induced even by 
localized manipulation of the stomach, while the rest of the viscera 
are protected, causes lowering of the CO. content and CO, capacity 
of the blood, and also of arterial pressure. If the lowering of the 
CO, capacity is pushed beyond the apparently critical level, be- 
tween 33 and 36 volumes per cent, the disturbance of the vital 
equilibrium results fatally. 
The same duration and degree of localized manipulation admin- 
istered while the subject is inhaling 6 or 7 per cent of CO: does 
not cause any marked lowering of the CO, capacity, arterial 
pressure, or general vitality. 
Below the critical level for the CO, capacity, treatment by the 
administration of 7 to 10 per cent CO, in the air breathed does 
not cause restoration of CO, capacity or arterial pressure. 
These results are in general harmony with the conception of 
acapnia as a factor in shock; long advocated in papers from this 
laboratory. | 
Further investigations are under way on the therapeutic and 
prophylactic sides.° | 
The expenses of the investigations reported in this series of 
papers have been defrayed by the Loomis Medical Research 
Fund. 
6Papers dealing with the effects upon the circulation of excess and 
deficiency of CO, will be published shortly in the Journal of Pharma- 
cology and Experimental Therapeutics. 
