242 Historical 



by Meyer-Ahrens and many others besides; since this part of his 

 work contains no personal observation, I shall not speak of it. But 

 from the part devoted to symptomatology, I extract a very good 

 summary of the symptoms from which mountain travellers have 

 suffered in different degrees: 



The principal symptoms or at least those which occur oftenest in 

 man are: discomfort, distaste for food, especially distaste for wine 

 (however, the contrary has sometimes been noted), intense thirst 

 (especially for water, which quenches the thirst best), nausea, vomit- 

 ing; accelerated and panting respiration; dyspnea, acceleration of the 

 pulse, throbbing of the large arteries and the temples; violent palpi- 

 tations, oppression, anxiety, asphyxia; vertigo, headache, tendency to 

 syncope; unconquerable desire for sleep, though the sleep does not 

 refresh but is disturbed by anguish; finally, astonishing and very 

 strange muscular fatigue. These symptoms do not always appear all 

 together .... Others are observed, although less frequently, such as 

 pulmonary, renal, and intestinal hemorrhages (in animals also); 

 vomiting of blood; oozing of blood from the mucous membrane of the 

 lips and the skin (due merely to the desiccation of these mem- 

 branes), blunting of sensory perceptions and the intelligence, impa- 

 tience, irritability, .... finally, buzzing in the ears. (Pages 100-101.) 



But the chapter most interesting to us is that on etiology. I 

 quote here the principal passages: 



All that we have just said about the etiology of mountain sickness 

 shows: 1) that it appears at varying altitudes; 2) that meteor- 

 ological conditions, temporary or general personal characteristics, and 

 the speed of walking vary the altitude at which one is attacked and 

 the severity and number of the symptoms. 



When one sees the appearance of mountain sickness correspond 

 to varying altitudes, he asks himself what circumstances depending 

 upon the altitude are capable of causing the phenomena which con- 

 stitute it. In my opinion, the principal role belongs to the decrease of 

 the absolute quantity of oxygen in the rarefied air, the rapidity of 

 evaporation, and the intense action of light, direct or reflected from 

 the snow, whereas the direct action of the decrease of pressure should 

 be placed in the second rank. I find the immediate causes of mountain 

 sickness in the changes made in the composition and the formation 

 of the blood by the decrease in oxygen and the exaggerated evapora- 

 tion, changes to which are added others due to the action of light 

 on the cerebral functions, an action which affects the preparation of 

 the blood liquid. 



These suppositions permit us to include — if we also take into 

 account individual constitutions — all the phenomena of mountain sick- 

 ness, without needing to appeal to the -direct action of the decrease 

 in the weight of the air. This explains the acceleration of the respira- 

 tory movements and the circulation, the congestions, the hemorrhages, 

 the functional disturbances of the brain and the extraordinary fatigue 

 of which almost all travellers complain. "We see too why mountain 



