80 Historical 



frequently, when I ascend steep slopes at these great heights. I tested 

 this again in my last trip to Buet. While we were climbing the slope 

 covered with soft snow which crowns the mountain, I absolutely had 

 to stop every fifty steps, and M. Pictet, more sensitive than I to this 

 effect of the rarity of the air, counted his steps without telling me, 

 and found that he could not take more than forty without getting his 

 breath. (P. 483-85.) 



But that was nothing compared to what he was to observe in his 

 trip to Mont Blanc. Already several attempts had been made to 

 reach the summit of this colossal mountain. De Saussure recorded 

 for us the account of these vain attempts, and it is clear that the 

 physiological symptoms experienced by those who made these at- 

 tempts had much to do with their failure: 



§1103. In 1775, four guides from Chamounix tried to reach the 

 summit by the mountain of La Cote .... Everything seemed to 

 promise them perfect success; .... but the reflection of the sun upon 

 the snow and the stagnation of the air in a great valley of snow 

 which seemed to lead them directly to the crest of the mountain 

 gave them a feeling of suffocating heat, as they said, and at the same 

 time gave them such distaste for the provisions with which they were 

 supplied, that, worn out with lack of food and weariness, they 

 retraced their steps. (Vol. II, p. 550.) 



§1104. In 1783, three other guides made the same attempt by the 

 same route. They passed the night at the top of the mountain 

 La Cote, crossed the glacier, and followed the same valley of snow. 

 They were already fairly high and were advancing courageously, 

 when one of them, the most daring and sturdy of the three, was seized 

 almost suddenly by an absolutely unconquerable desire to sleep; he 

 wanted the other two to leave him and go on without him; but they 

 could not consent to abandon him and leave him sleeping on the snow, 

 convinced that he would die of sunstroke; they gave up their attempt 

 and returned to Chamounix. For this need of sleep, produced by the 

 rarity of the air, ceased, as soon as he was in a denser atmosphere in 

 the descent .... The heat gave them all great distress; they had no 

 appetite; the wine and the food which they took with them had no 

 attraction for them. 



September 13, 1785, De Saussure himself attempted the ascent 

 with M. Bourrit and his son. He slept at the hut (1422 fathoms) : 



§1112. M. Bourrit and his son even more than he were a little 

 affected by the rarity of the air; they did not digest their dinner well, 

 and could eat no supper. As for me, since the thin air inconveniences 

 me only when I am exercising violently in it, I passed an excellent 

 night there. 



The next day, he mounted to an elevation of 1900 fathoms; the 

 snow stopped him. 



But the ascent of Mont Blanc had become a dominating idea in 



