1006 Summary and Conclusions 



acclimated to the high barometric pressure of our country, but on 

 vigorous condors caught in their usual habitat: conditions difficult 

 to realize. I should also have to know the oxygen content of their 

 blood, and especially, as you can easily ascertain, since I have 

 indicated it above, its oxygen capacity. The amount of blood they 

 contain would also be interesting information. Nothing would be 

 more interesting, after all, than to try to establish their respiratory 

 and nutritional equation by air analyses, by weighing food, and by 

 calorimetric measurements. 



Perhaps, after all this had been observed, it would be possible 

 to account for the strange resistance which they present to the 

 effect of rarefied air, even while they are performing the consider- 

 able work of ascent by flight. 



In finishing this chapter, I shall recall the fact that plants, for 

 the same reason as animals, are affected by the lessened tension of 

 the oxygen which they respire in lofty regions. This element ha.i 

 till now been neglected by botanists, rightly preoccupied with the 

 study of the geographical distribution on the mountains, of the in- 

 fluence of temperature, of the intensity of the solar rays, and of 

 the hygrometric conditions. Usually they do not speak of it, or 

 they deny its importance. For example, M. Radau, 31 mentioning 

 the fact that certain mountain plants cannot live in our country 

 with temperatures like those of their native land, says expressly: 

 "Atmospheric pressure has probably nothing to do with data of this 

 sort." But my experiments show that vegetation, and germination 

 perhaps even more, are markedly delayed in rarefied air. 



They also bring to light a certain inequality of resistance among 

 different vegetable types, the cruciferae seeming less susceptible 

 than the grasses. Finally, and this is an interesting coincidence, 

 we have seen that the phenomena of vegetable life stop precisely 

 at the pressure of 7 cm. of mercury, which is fatal to all animals. 

 It is then at this low oxygen tension (2.5) that organic oxidations 

 in all living beings become so sluggish that they can no longer 

 maintain vital equilibrium. 



5. Medical Applications. 



I make haste to declare that I only suggest this point, which is 

 outside the scope of my studies. Dr. Jourdanet first had the idea 

 of using artificially rarefied air in the treatment of different dis- 

 eases, notably anemia and consumption (tuberculosis of the lungs) . 

 I refer the reader to his books for the study of the results obtained. 

 Both before and after him, residence at lofty heights has been and 



