174 NATT BAL ll I- J "UV OF 



this fact is still oftener observable when distinct races of the 



same type have contested the tenure of the soil. \\ e Bee both 

 these cases repeatedly exemplified in all the metre isolated 

 mountain systems, for the chains are guides to further | 

 ress. It is shown in the Neelgherries, the Crimea, the Carpa- 

 thians, the Pyrenees, the Alps, the Atlas, and even in the 

 group of Northern South America — all the residence of very 

 diffen nt tribes, driven to take refuge in them at various peri- 

 ods, and a single ridge or valley often separating people totally 

 distinct in religion, language, and aspect. The conditions of 

 their several states of existence often produce a more certain 

 and impressive history of the transactions in foregone ages, in 

 a given country, than its hest chronicles afford. 



Thus, the temporary tenure of Caucasian tribes, the Kin- 

 tomoey, Scythi, Yuchi, Yeta, and Sac®, and the overlapping 

 nations in the north-east of the centre, and in north-western 

 Asia, is proved by their insulation or expulsion by the Mongo- 

 lic, to whom the whole expanse is more genial; while, for the 

 same reason, this last named stock could not maintain its con- 

 quests in Europe, nor to the south of the central ridge in 

 Asia. 



But the white and negro races of Africa readily inter- 

 mix. The woolly-haired form has there no pretensions on 

 the debatable land between them. The Caucasian might 

 have assumed mastery beyond it, had not the force of nature 

 interposed; for this race does not and cannot multiply in the 

 centre of Negro existence ; and in the warmer valleys of 

 the intermediate spaces, such as that of the Nile, only a mixed 

 Semitic stock possesses durability. It has been calculated, 

 that, since the introduction of the Mameluke power, not 

 less than five millions of well-chosen colonists, of both sexes, 

 from higher Central Asia, have been introduced, not to wear 

 out a life of slavery, but one of power and rule ; yet no fourth 

 generation of this stock can anywhere be shown in Egypt, 

 even with all the additional aid of Syrian and Persian females, 



