240 EFFECTS OF RAREFIED AIR. 



ascending ever so gentle a rise, and a weight about the legs, 

 as if gravity were exercising an undue amount of influence 

 on them. On the upper ranges of the Himalayas, the natives 

 attribute the more unpleasant sensations to the exhalations 

 from certain poisonous plants ^ growing at great heights per- 

 meating the air ; and my shikarees, when telling me about 

 shooting localities close under the snowy range, would de- 

 scribe some of them as being bad for hhik (poison), whilst 

 others which were as high, or higher, they said, were free 

 from it. Although this idea is generally ridiculed by Euro- 

 peans, it is so universally entertained throughout the Hima- 

 layas by the hill-men, as to make one almost think there 

 must be some foundation for it. I certainly have seen the 

 deadly aconite flourishing luxuriantly on the higher ranges, 

 where the tall spike-like heads of its intense blue blossom 

 have a very striking and beautiful effect, shooting up, as 

 they often do, from some moist green spot, thickly be- 

 sprinkled with buttercups, amidst grey rocks and snow-beds. 

 At great heights I have always felt the effects of rarefied 

 air more on table-lands, or where the surroundings were 

 comparatively level or undulating, than at similar elevations 

 where they were very steep, either upward or downward — 

 and I believe my experience in this respect is not singular. 

 Moreover, it is remarkable that at Leh, which is under 

 12,000 feet, but situated on an extensive open plateau, 

 even the Tartars themselves are said to complain of short- 

 ness in breathing and headache. Erom this it would secui 

 either that height is not the sole cause of, at any rate, the 

 latter sensation, or the rarity of the air must vary consider- 

 ably at equal altitudes, under different conditions. These 

 ideas, which have been suggested to me not only by my 

 own experiences, but also by those of other Himalayan 

 travellers with whom I have talked on the subject, may 

 perhaps be considered rather wild, so let us now, turn 



1 A CaKfornian shrub, commonly called " poison-oak," is said by the natives 1 

 to have a noxious effect on those who inhale the air in its close vicinity. 



