50 EPIDEMIC WARS. 



the India caravan, as on the banks of navigable rivers, 

 arose great and wealthy cities, which perished when the 

 route was changed. Open the book of Universal His- 

 tory at what period we may, it is always the India 

 trade which is the cause of internal industry and 

 foreign negotiation. 



The intercourse between the Indians, Chaldseans, and 

 Egyptians was often interrupted by wars, which recurred 

 like epidemics, and which, like epidemics, closely re- 

 sembled one another. The roving tribes of the sandy 

 deserts, the pastoral mountains or the elevated steppe- 

 plateaux, pressed by some mysterious impulse — a 

 famine — an enemy in their rear — or the ambition of a 

 single man — swept down upon the plains of the Tigris 

 and Euphrates, and thence spread their conquests right 

 and left. Sometimes they merely encamped, and the 

 natives recovered their independence. But more fre- 

 quently they adopted the manners of the conquered 

 people, and flung themselves into luxury with the 

 same ardour which they had displayed in war. This 

 luxury was not based on refinement, but on sensuality, 

 and it soon made them indolent and weak. Sooner or 

 later they suffered the fate which their fathers had 

 inflicted, and a new race of invaders poured over the 

 empire, to be supplanted in their turn when their time 

 was come. 



Invasions of this nature were on the whole beneficial 

 to the human race. The mingling of a young powerful 

 people with the wise hut somewhat weary nations of 

 the plains produced an excellent effect. And since the 

 conquerors adopted the luxury of the conquered, they 

 were obliged to adopt the same measure for supplying 

 the foreign goods — for luxury means always something 

 from abroad. As soon as the first shock was over the 



