1024 Summary and Conclusions 



ill and die if the experiment lasts long enough, or if the amount of 

 free oxygen is large enough, exactly as do the vibrios of the butyric 

 fermentation 7 in the presence of atmospheric air. The red cor- 

 puscle alone seems an exception, for it appears quite essentially 

 aerobic; but I am inclined to think that that is only an illusion, for 

 this corpuscle itself, when its constituent stroma, its globuline, 

 contains free oxygen after the saturation of its oxygen-loving pig- 

 ment (hematocrystalline) , dies like the other anatomical elements 

 (p. 842). So, in the regular state of things, as we have seen, the 

 hemoglobin is never saturated with oxygen. We must note, fur- 

 thermore, that the aerobic micro-organisms, like the bacteria, also 

 die under the influence of compressed oxygen; we can then form 

 the hypothesis that they have in them, like the red corpuscle, some 

 material eager for oxygen whose oxygenated combination feeds 

 their own constituent substance. In this hypothesis, all living 

 beings and all their parts taken separately would be anaerobic. 

 At any rate, the parallelism is perfectly established between the red 

 corpuscles and the bacteria on one hand and the anatomical ele- 

 ments and the vibrios on the other. But however different they 

 appear to be, divided here two by two, they are all alike in the 

 death which strikes them rapidly in the presence of a sufficient 

 amount of dissolved oxygen. 



Before leaving this subject, let us call attention once more to 

 this new application of the general rule, that when a poison strikes 

 the whole organism, it is the nervous system which reacts first. 

 The dog in compressed air first has convulsions; and these, disturb- 

 ing the mechanisms whose harmony is necessary for the main- 

 tenance of life, kill him before the other anatomical elements are 

 fatally attacked; but for the latter it is only a question of time. His 

 blood is still capable of recalling to life another bloodless dog; 

 but if it is agitated for some hours under oxygen pressure, it will 

 kill the healthy animal into which it is injected, far from being 

 able to save the dying bloodless dog. In the same way, the tail of 

 a rat which has been killed by oxygen can be grafted perfectly; 

 but a longer exposure to compressed oxygen will kill its elements 

 and the graft will be absorbed without suppuration. 



2. Low Pressures. 



Under this title, as I did in Subchapter II of Chapter IV, I in- 

 clude pressures between one and five atmospheres of air, in which 

 the oxygen tension varies between that of air (20.9) and the 100 

 of pure oxygen. With these tensions, as I have just remarked, 



