342 LIFE OF HORACE BENEDICT DE SAUSSURE 



in itself produce the form of exhaustion known as mountain- 

 sickness, but that this is the result of altitude coupled with the 

 muscular exertion of walking uphill, and that its sjinptoms cease 

 in repose or during a descent. Rest, he insists, even for a few 

 minutes, removes every trace of discomfort. 



The whole question has of late years been most carefully and 

 lengthily discussed by eminent physiologists and mountaineers, 

 and de Saussure's limited observations have been largely super- 

 seded. Experience has shown that the susceptibility to the effect 

 of rarefied air varies in individuals as much as the susceptibility to 

 sea-sickness does. It also varies at different periods in the same 

 individual on the same mountain e.g. Mont Blanc ; while the 

 relatively small proportion of the climbers of that mountain 

 seriously affected in recent years may suggest that coarse food and 

 rough lodging, and perhaps also strained nerves, had something 

 to do with the frequent sufferings of mountaineers, guides as 

 well as tourists, in the days before the Grands Mulets boasted a 

 ' hotel ' and the refuge near the Bosses served as a coffee -stall. 

 A further observation I have not yet seen recorded may perhaps 

 be added. Inconvenience is far more commonly experienced on 

 snow-slopes than on rocks. It would seem that the monotonous 

 exertion of tramping uphill in snow causes a greater muscular 

 strain than the more varied gymnastics of a rock climb. That any 

 prolonged stay at high altitudes or any sudden transference to 

 them sensibly affects the human frame is beyond question. But 

 so far as Alpine heights are concerned, de Saussure's statement is 

 sustainable. It is possible to spend several hours on the top of 

 Mont Blanc or Monte Rosa without experiencing any of the 

 symptoms of mountain-sickness, experto crede. I have slept not 

 uncomfortably 5000 feet higher. 



In the early summer of 1784 de Saussure started on a family 

 tour through the Swiss lowlands with his wife, sister, daughter, 

 his sister-in-law Madame Tronchin, and his friend Trembley. 

 From Lucerne he made an excursion to Engelberg and the Joch 

 Pass, with which he combined an ascent of the Ochsenstock 

 (9883 feet). The party drove on to Zurich, St. Gall, Constance, 

 and Basle ; it must have been on this occasion that he took 

 measurements of depths in the Lake of Constance. At Zurich he 

 called on ' Monsieur Gesner, the poet.' This was Solomon Gesner, 



