26o STUDIES OF NATURE. 



a part of the year, into the flreets of that City, 

 without having the face covered with a veil, on 

 account of the fand with which the air is loaded. 



When IJhrand-Ides arrived on the frontiers of 

 China, at the extremity of the outlet of the moun- 

 tains in the neighbourhood of Xaixigar, that is, 

 at that part of the creft of the Afiatic Continent, 

 which is the mod elevated, from which the rivers 

 begin their courfes, fome to the North, others to 

 the South, he obferved a regular period of thefe 

 emanations. *' Every day," fays he*, " at noon 

 *' regularly, there blows a ftrong guft of wind, 

 *' for two hours together, which, joined to the 

 *' fultry heat of the Sun by day, parches the ground 

 *' to fuch a degree, that it raifes a dufl almofl in- 

 " fupportable. I had obferved this change in the 

 ** air fome time before. About five miles above 

 *' Xaixigar, I had perceived the Heavens cloudy, 

 *' over the whole extent of the mountains -, and 

 " when 1 was on the point of leaving them, I faw 

 " perfeâ: ferenity. I even remarked at the place 

 *' wheue they terminate, an arch of clouds, which 

 " fweeped from Weft to Eaft, as far as the moun- 

 " tains of Albafe, and which feemed to form a fe- 

 ** paration of climate." Mountains, accordingly, 

 poffefs, at once, nebulous and foffil attractions. 



* Journey from Mofcow to China, chap. xi. 



The 



