viii INTRODUCTION, 



extracts in support of the foregoing statements. Those who desire 

 to pursue the matter in detail may usefully turn to the very com- 

 prehensive summary in La Pression Barometrique, by M. Paul 

 Bert/ Avhere 156 pages are devoted to experiences in high places, 

 25 more to aeronauts, and 120 more to theories. Evidence of a 

 nature similar to that which is quoted by M. Bert continues to 

 accumulate, and is often, apparently, of a contradictory character. 

 For example, since returning from the journey which is described 

 in the following pages, three writers upon Mexico ^ have mentioned 

 that breathing is affected in that city by the ' rarefied atmosphere,' 

 although the altitude in question is less than 8000 feet above the 

 sea ; while on the other hand, quite recently (in speaking of the 

 Southern Andes up to heights 13,800 feet above the sea). Dr. 

 A. Plagemann says, " with regard to the effects of rarefied air on 

 the body at high elevations, neither he nor his companions suffered 

 at all. ^'^ Still more divergent is the statement by Mr. W. W. 

 Graham that he reached nearly the height of 24,000 feet in the 

 Himalayas, and that ^^ neither in this nor in any other ascent did 

 he feel any inconvenience in breathing other than the ordinary 

 panting inseparable from any great muscular exertion.^'* 



This unique experience has met with little credence in India. 



* G. Masson, Paris, 1878. This work has received the highest honours in 

 France. The experiments made by M. Bert upon himself at low pressures, although 

 extremely interesting, left off sooner than could have been desired. In the first of 

 the two experiments which I quote in the Appendix to this volume, he submitted 

 himself to an artificial diminution of pressure somewhat greater than that which is 

 experienced at the summit of Chimborazo, and in the second one to about the press- 

 ure which would be enjoyed on the top of Mount Everest. But this was done for 

 only a brief space of time. The first experiment extended over only sixty-six minutes 

 and the second one over eighty-nine minutes ; and, as soon as any ill effects com- 

 menced to manifest themselves, M. Bert refreshed himself with oxygen. The 

 experiments shewed that oxygen may exercise a beneficial influence. 



2 See A Trip to Mexico, by H. C. R. Becher, Toronto, 1880, p. 73 ; Mexico To- 

 Day, by T. U. Brocklehurst, London, 1883, p. 28 ; and Winter in the Slant of the 

 Sun, in Good Words, 1887, p. 245, by the Bishop of Rochester. 



3 Proceedings of the Royal Geographical Society, April 1887, p. 249. 



* Proc. Boyal Geog. Soc, August 1884, p. 434. 



