334 Historical 



by walking, running, any expenditure of energy. We have had 

 many examples of this: one of the best guides of the Oberland 

 (page 94), whom a rather strenuous effort twice makes blind; the 

 traveller Weddell, till then immune to the soroche, who is stricken 

 after a rapid excursion (page 48) ; de la Touanne, falling on the 

 ground almost unconscious, because he wished to go faster sud- 

 denly (page 36) ; d'Orbigny, who, thinking himself acclimated, 

 was compelled to stop every time he waltzed (page 38) ; Hedringer 

 falling on the snow, because he wished to run to the summit of 

 Mont Blanc (page 96) ; an inhabitant of the Alpine mountains, who, 

 trying to outstrip his companions, rolls over "as if some one had 

 shot him" (page 116). Travellers say that it is to the eagerness of 

 the horses, which spring forward under the spur, that their fre- 

 quent deaths are due, whereas the mules, patient and obstinate, 

 survive because they refuse to quicken their pace. It is walking 

 uphill which especially fatigues and exhausts. 



This fatal effect of muscular activity is felt at all altitudes. But 

 in regions of moderate elevation rest is sufficient to dissipate its 

 effects and restore complete calmness. And that is perhaps the 

 most peculiar characteristic -of mountain sickness. To the uneasi- 

 ness of the traveller, to his extreme fatigue, to his grievous dis- 

 tress, there succeeds an unexpected comfort, as soon as he stops, 

 sits down, or particularly lies down: his heart regains its rhyfhm, 

 respiration becomes regular, a feeling of energy returns, all as if 

 by enchantment; so that after a few minutes, astonished both by 

 these unknown discomforts and this sudden cure, the inexpe- 

 rienced traveller confidently resumes his climbing. But soon he is 

 again attacked and conquered. 



On loftier mountains, rest, even rest in a horizontal position, 

 even if it dissipates the most violent symptoms, does not, however, 

 restore calmness. Palpitations, suffocations, trouble or prevent 

 sleep. Sometimes a strange symptom appears; during the night, 

 at dawn especially, sudden respiratory distress awakens the sleeper 

 with a start (see pages 39, 54, 55, 132, 149, 155, 158, 160) . A few deep 

 inspirations restore calmness; probably it is a consequence of this 

 forgetting to breathe of which de Saussure had spoken (page 83) ; 

 imminent asphyxia awakens the sleeper suddenly. 



Such is the series of symptoms which, in different degrees, at 

 different altitudes, attack mountain climbers and aeronauts. It 

 seems that there is no great difference, except in intensity, be- 

 tween the symptoms observed in the different mountainous 

 regions. Although the symptoms which we have described appear 

 sooner in our Alps than in the Andes and the Himalayas, they 



