Summary and Discussion 335 



never reach there the dangerous severity which threatens the 

 lives of travellers and their guides, even natives, in the other 

 regions. That is because the height of Mont Blanc (4810 meters) 

 is the maximum which one can reach in our Europe, and because 

 one remains there only a few hours at the most. Conditions in the 

 Himalayas are far different, because there one remains for a long 

 time on plateaux at an altitude of more than 4000 meters, crossing 

 almost every day passes which reach an elevation of 5000 to 5500 

 meters. 



A harmful influence whose dangerous effects many travellers 

 have mentioned is that of the wind. "There blows in this place," 

 says Acosta, whom I must constantly quote, "a little wind which 

 is not too strong or violent. But it is so penetrating that men fall 

 dead from it, almost without perceiving it" (page 25) . M. Lepileur 

 also suffered from the wind to a much less dangerous degree (page 

 103). The Schlagintweit brothers also complain of it very bitterly 

 (page 155) , and Henderson claims that it often kills travellers 

 (page 159). 



Many narratives agree in stating that the symptoms are parti- 

 cularly severe at points on the mountain where the air is renewed 

 with greater difficulty. Should this irregularity be attributed to 

 the heating of this air, expanded by the sun? Or to the tediousness 

 of walking in these monotonous passages? The observations of 

 M. Javelle and M. Forel tend to support this latter hypothesis. 

 They state, in fact, that mountain sickness disappears in dangerous 

 spots (page 289) and also as a result of attentive observation of 

 the landscape or oneself (page 292) . 



It would not be very interesting to dwell on the medications 

 used by the natives against the symptoms of mountain sickness. 

 They generally agree in forbidding alcoholic beverages; in 

 America, they praise bleeding, especially for animals. In the Andes 

 protective powers are attributed to garlic or onion placed in the 

 nostrils of the animals; in the Himalayas, acid and dried fruits are 

 used. Almost everywhere it is recommended that one should eat 

 little and often. M. Dufour declares that he dispelled an already 

 violent attack of mountain sickness merely by eating a piece of 

 bread (page 290). 



3. Theoretical Explanations. 



We may divide into two great categories the hypotheses and 

 the theories put forward to explain mountain sickness: some of 

 them, by far the most interesting, try to settle the mechanical, 

 physical, or chemical role of the diminished atmospheric pressure; 



