CHAP. XI. ALLUVIAL SOIL. 5i 



White River is the principal stream, being much 

 broader, bringing a larger su})})]y of water, and ]))-()- 

 bably coming from a greater distance tlian the Bhie 

 River, or Abyssinian branch, which rises a little 

 beyond the lake Dembea, still this last claims the 

 merit of possessing the real peculiarities of the Nile, 

 and of supplying those fertilising properties which 

 mark its course to the sea. The White River, or 

 Avestern branch, likewise overflows its banks, but 

 no rich mud accompanies its inundation ; and 

 though, from the force of its stream (which brings 

 down numbers of large fisli and shells at the com- 

 mencement of its rise, probably from passing- 

 through some large lakes), there is evidence of its 

 being supplied *by an abundance of heavy rain, we 

 may conclude that the nature of the mountains 

 at its source differs considerably from that of the 

 Abyssinian ranges. 



Besides the admixture of nitrous earth, the 

 Egyptians made use of other kinds of dressing 

 for certain produce ; and in those places where 

 the vine was cultivated on alluvial soil, we may 

 conclude they found the addition of gravel be- 

 neficial to that valuable })lant, — a secret readily 

 learnt from its thriving condition, and the supe- 

 rior quality of the grape in stony soils ; and some 

 produce was improved by a mixture of sand. Nor 

 were they neglectful of the advantages offered 

 by the edge of the desert for the growth of certain 

 plants, which, being composed of clay and sand, 

 was peculiarly adapted to such as recpiiied a liglit 

 soil ; and the cultivation of this additional tract, 



E 2 



