146 THE BORDERLAND OF SCIENCE. 



could swallow it down in gulps, I could take twenty- 

 five or twenty-six paces without stopping.' 



It must not be overlooked, however, that some of the 

 effects thus experienced appear to be due to the 

 presence of impure air. For experiments made by De 

 Saussure showed that air near the surface of snow 

 contains less oxygen than the surrounding air; and 

 Boussingault points out respecting ' certain hollows and 

 enclosed valleys of the higher part of Mont Blanc in 

 the Corridor, for instance that people generally feel 

 so unwell when traversing it that the guides long 

 thought this part of the mountain impregnated with 

 some mephitic exhalation. Thus even now, whenever 

 the weather permits, people ascend by the Bosses ridge, 

 where a purer air prevents the physiological disturbances 

 from being so intense.' 



There are, indeed, parts of the earth where, at an 

 elevation nearly as great as that at which De Saussure 

 experienced such unpleasant effects, the inhabitants of 

 considerable cities enjoy health and strength. As 

 Boussingault well remarks, 'When one has seen the 

 activity which goes on in towns like Bogota, Micui- 

 parnpa, Potosi, &c., which have a height of from 8,500 

 feet to 1 3,000 feet ; when one has witnessed the strength 

 and agility of the torreadors in a bull fight at Quito 

 (9,541 feet) ; when one has seen young and delicate 

 women dance for the whole night long in localities 

 almost as lofty as Mont Blanc ; when one remembers 

 that a celebrated combat, that of Pichincha, took 

 place at a height as great as that of Monte Rosa 



