308 



PHYSICAL GEOGRAPHY. 



from any noxious taint derived from earths and minerals, except from those in its 

 immediate channel. The same property of being remarkably pure and salutary, is 

 ascribed by Herodotus to one of the Susianic rivers, of which alone, according to tradition, 

 none but the kings of Persia drank. 



" There Susa, by Choaspes' amber stream, 

 The drink of none but kings." 



The Susianic streams, along with the Nile, may not improperly be styled the oldest rivers 

 of the globe, because of their place in its most ancient traditions and histories ; and 

 however subordinate to the gigantic currents of the western hemisphere, those of the 

 eastern in general present higher points of interest, in their long known identification 

 with the destinies of mankind. If not the actual birth-place of man, the great plains 

 on the banks of the Tigris and the Euphrates were the abode of the founders of the 

 diluvian race. There, the two greatest cities of the ancient world, Nineveh and Babylon, 

 rose into magnificence There, a supernatural finger traced the doom of the latter upon 

 the palace wall of its trembling monarch, while an exiled Jew, in the majesty of inspiration, 

 gave him the interpretation of the mystic writing. There, too, the splendid empire of the 

 Medes and Persians fell a prey to the Macedonian on the field of Arbela, while, in later 

 ages, the same neighbourhood witnessed the catastrophe of Cunaxa, and the bold bearing 

 of the indomitable ten thousand the defeat and death of Crassus the retreat of Mark 

 Antony the fall of the apostate Julian and the short-lived glory of Bagdad. How 

 different the associations connected with the Arkansas and the Osage to those of the 

 Euphrates and Tigris ! 



CHAPTER VII. 



LAKES. 



ARGE or small collections of water, fresh or saline, 

 and surrounded by land, are termed lakes, and have 

 an aspect, upon the face of the continents, similar to 

 that of islands in the ocean. They differ from re- 

 servoirs in not being artificial, but natural, forma- 

 tions ; and from lagoons, which are simply the 

 overflowings of rivers in the season of flood, or 

 portions of the sea which have encroached upon 

 the land, and been separated from the parent deep 

 by the gradual accumulation of banks of sand, or 

 barriers of earthy material. They differ also from 

 pools, which are mere collections of rain-water in 

 hollow places, generally dried up in periods of 

 drought ; whereas true lakes are formed in va- 

 cuities, either by streams flowing into them from 

 the surface, or by springs gushing up from their bed. 

 These fluvial formations may be referred to a great 

 variety of causes, the action of some being of 



ancient, and others of comparatively modern date. It is supposed that many lakes are the 

 remains of the universal ocean which once covered the earth, the waters of which have 



