Death in Closed Vessels 533 



cipal ones are due to the calmness or the agitation of the animal 

 enclosed, which uses up more or less quickly the quantity of air 

 left at its disposal. 



We now have to compare graphs A and C, that is, the capacity of 

 the vessels with the exhaustion of oxygen. Here again the curves 

 have little agreement. We even find strongly opposed results, as 

 in that of Experiment 19, in which maximum exhaustion corre- 

 sponds to a small vessel, and that of Experiment 24, where in a 

 very large vessel there was little exhaustion compared to Experi- 

 ments 14 and 16, which give opposite results. But if we take an 

 average, we see that numbers less than 3.5 (graph A) correspond 

 to an average of 1.8 liters, while those that are greater correspond 

 to 1.6 liters. There is then some advantage in vessels of large 

 capacity, another conclusion agreeing with those of Claude Bernard. 

 But the differences are very slight, and when we examine these 

 numerous results, we can understand the apparent contradictions 

 of investigators. 



Therefore, whatever point of view we take, we find that the re- 

 sults of the experiments under diminished pressure agree with all 

 that we know about asphyxia in closed vessels. We are then 

 more and more led to see in the rarefaction of the air only a physical 

 process which leads to the same end as the impoverishment of 

 oxygen, a chemical process. The following data also corroborate 

 this view. 



We know that at very low temperatures and under normal 

 pressure animals exhaust much less the oxygen of the air in 

 which they are confined than they do at an average temperature. 

 Is the same thing true for death in closed vessels at low pressure 7 

 The following experiments give the answer to this question. 



Experiments XLI to XLIII, simultaneous. December 12. Pressure 

 77 cm. The temperature of the laboratory is +6°. After the sparrows 

 had been placed under the bell-jars, the latter were packed in snow, 

 and the temperature dropped to about + 2°. 



XLI. Bell-jar of 2.25 liters. 



Entered at 2:40. Pressure brought to 54 cm., and the cold lowers 

 it to 52 cm. The bird is found dead at 4 o'clock. 

 Lethal air: O 8.3; CO,' 11.4. 



CO. 



CO. + 0* - 19.7; = 0.90. 



O. 



XLII. Bell- jar of 3.2 liters. 



Entered at 2:50. Pressure brought to 44 cm. by vacuum and cold. 

 At 4 o'clock is breathing with great difficulty; at 4: 15, dead. Lived 1 



