Theories and Experiments 221 



a poisoned wind; generally, the emanations of certain plants are 

 supposed to give these toxic qualities to the air. 



Fraser 31 is the first to give us this curious information; we 

 must admit that he makes haste to reject this explanation, and for 

 an excellent reason: 



I did not suspect that the altitude could affect the strength and 

 the lungs so severely, and yet it was the only cause, no matter how 

 difficult the ascent; for in that respect we had had days before that 

 were at least as bad; and although we were told that the air was 

 poisoned by the odor of flowers, and although there were indeed a 

 profusion of them during the first part of our journey, most of them 

 had no odor, and we could not perceive any in the air. More than 

 that, we were particularly distressed when we reached the lofty gorge 

 of Bamsooroo, where there was no vegetation, and consequently no 

 perfume of flowers. (P. 449.) 



Dr. Govan, 3 - who accompanied Captain Al. Gerard on his first 

 journey in 1817, reports the same tradition, without giving it any 

 more credence. But much astonished by the lack of proportion 

 already noted by travellers between the altitude and the intensity 

 of the symptoms, he has the peculiar idea of having electricity play 

 an active part in these phenomena: 



On the highest peaks of the mountains of Choor there first appear 

 the juniper-tree, the alpine rhododendron, and the tall aconite, the 

 toxic effects of which, when it is used internally, are well known, and 

 seem to have given rise to the belief common among the natives that 

 it poisons the surrounding air; I can find no basis for this opinion, 

 except that in the lofty places in which this beautiful plant grows, 

 travellers often, but not always, experience disagreeable symptoms, 

 usually attributed to the expansion of the air. 



If the symptoms considered by eminent naturalists as resulting 

 from this expansion should really be ascribed to it, why are they not 

 proportional to the elevation and the rarefaction, and why do these 

 symptoms not invariably appear when the elevation and rarefaction 

 reach a certain degree? 



On two occasions I passed the night at elevations more than 

 14,000 feet above the line of perpetual snow; I crossed the Rol-Pass 

 (much above 15,000 feet), accompanied by 40 native soldiers, without 

 anyone of us experiencing these painful symptoms. Now, in the same 

 places, and even at lower elevations, they have been observed in other 

 ascents and predicted in advance by the natives. 



All of this seems to indicate that these symptoms result from less 

 general atmospheric circumstances, such as the electric force, which, 

 in the case of such lofty conductors, must be in a state of constant 

 fluctuation. (P. 282.) 



Captain Al. Gerard, 13 in the account of his journey of 1818, also 

 mentions poisonous plants: 



