354 Comparative Physical Geography. 



traveller, crossing the lofty chain of the Himalaya, passes suddenly 

 from the polar climate of the high table-lands of Thibet to the tropical 

 heats and the rich nature of the plains of the Indus and the Ganges. 

 Yet, as we have said, this great wall, which separates the north from 

 the south, is rent at several points. Between the Hindoo-Khu and the 

 Caucasus, the depressed edge of the table-land of Khorasan, between 

 the Caucasus and the Balkan, the plains of the Black Sea and of the 

 Danube open wide their gates to the winds and to the nations of the 

 shores of the Caspian and the Volga. Between the Pyrenees and 

 the Alps, the climates and the people of the south penetrate into the 

 north. 



Thus two opposite regions are confronted, one on the north, in 

 the cool temperate zone, with its vast steppes and desert table-lands, 

 its rigorous climates, its intense colds, its dry and starvehng nature ; 

 the other on the south, in the warm temperate zone, with its beauti- 

 ful peninsulas, its fertile plains, its blue heavens, and its soft climate, 

 its delicate fruits, its trees always green, its lovely and smiling na- 

 ture. 



The contrast of these two natures cannot fail to have a great in- 

 fluence on the people of the two regions. It is repeated, from the 

 history of the very earliest ages, in the most remarkable manner. In 

 the north, the arid table-lands, the steppes, and the forests, condemn 

 man to the life of shepherds and hunters ; the people are nomadic 

 and barbarous. In the south, the fruitful plains, and a more facile 

 nature, invite the people to agriculture ; they form fixed establish- 

 ments and become civilized. Thus, in the very interior of the his- 

 torical continent we find, placed side by side, a civilized and a bar- 

 barous world. 



Two worlds so different cannot remain in contact without reacting 

 upon each other. The conflict begins, one might say, with history 

 itself, and continues throughout its entire duration. There is scarcely 

 one of the great evolutions, particularly in Asia, not connected with 

 this incessant action and reaction of the north upon the south, and 

 of the south upon the north, of the barbarian world upon the civi- 

 lized world. At all periods we see torrents of barbarous nations of 

 the north issuing from their borders and flooding the regions of 

 civilization with their destroying waves. Like the boisterous and 

 icy winds of the regions they inhabit, they come suddenly as the 

 tempest, and overturn everything in their way ; nothing resists their 

 rage. But as after the storm nature assumes a new strength, so the 

 civilized nations, enervated by too long prosperity, are restored to 

 life and youth by the mixture of these rough but vigorous children 

 of the north. Such is the spectacle presented to us by the history of 

 the great monarchies of Asia and of their dynasties ; that of Europe 

 is scarcely less fertile in struggles of this kind. Some examples 

 which I proceed to recal to your memoi'y will be enough to convince 

 you of the powerful influence of this contrast. 



