614 Experiments 



At the first stroke of the pump, nothing comes. At the second, 

 about 3 cc; at the third, a considerable quantity of gas, and at the 

 fourth, almost nothing. The blood has not frothed perceptibly. Besides, 

 this is the same result as in the preceding experiment and is explained 

 by the small quantity of gas. 



Blood A contained per 100 volumes: CO,' 35.0; O* 19.2 

 Blood B contained per 100 volumes: CO? 16.2; O- 8.1 



These experiments do not permit us to draw any conclusions 

 as to the oxygen, because evidently at the return to normal pressure, 

 the oxygen of the air contained in the pulmonary vesicles was 

 partly dissolved in the blood of the lungs, which was then pumped 

 into the left heart. Moreover, the arterial blood was very red, 

 which had already perplexed F. Hoppe very much, as we saw in 

 the historical part of this book. But the carbonic acid is another 

 matter, and we can see that it was reduced to 19.0 cc. and 16.2 cc. 

 The proportion which had disappeared was, in Experiment 

 CLXXXI, 53.7 per cent. 



Now, referring to Table X, we find at the pressure of 17 cm. 

 (Exp. CLXXIX) a much greater loss of 74 per cent. But in the first 

 place, this loss is not an average, since it is the result of only two 

 analyses made on the same animal, in the same experiment, one 

 at 18 cm., the other at 17 cm., with a 12 minute interval. Further- 

 more, to reach this enormous decompression, which I have not 

 been able to reach since, I had to keep an animal for one hour at a 

 pressure below 30 cm. 



I will again call attention in this Experiment CLXXIX to the 

 very small proportion of carbonic acid which the blood retained 

 in passing from 17 to 26 centimeters pressure (analysis D) , in spite 

 of a quarter hour interval. I thought I should not include this 

 figure, Number 17, Table X, in the average of Column 15 and in the 

 graph of Figure 32, which expresses it. 



Another interesting point, on the contrary, is the return of nor- 

 mal proportions of oxygen and almost normal proportions of CO. 

 when the animal was restored to the pressure of 76 cm. (three 

 quarters of an hour afterwards). I have had numerous examples 

 of this return of the gases, examples still more rapid. 



As for the figures of the analyses B, C, D (Numbers 20, 21, 17 

 of Table X) , I think we must consider them as minima for carbonic 

 acid, and I preferred to set down on the graph C0 2 of Figure 31 

 the results furnished by the experiments at 7 centimeters, which 

 seem to be nearer the average and to comply better with the law of 

 the graph. 



It would be easy for me now to draw practical conclusions from 



