1 INTRODUCTION. 



between the dialects of the rudest nations, whose language 

 alone bears upon the question, we have less cause to wonder 

 at the resemblance between them than at the radical diver- 

 gence which they present, in sound, words, and construction. 

 And with respect to similarities of customs, all men have, 

 within certain limits, the same wants, and must, in innumer- 

 able cases, be conducted to the same means of satisfying 

 these wants ; and w r hen we connect with this general cause, 

 the effects of intercourse during unknown periods of time, 

 we have far less cause to wonder at the resemblances, than 

 at the differences, in the customs of nations. 



It will be seen, then, that great difficulties present them- 

 selves to the supposition of the derivation of all the varieties of 

 mankind from a common centre, at least within the period 

 which chronology assigns to the existence of the human race ; 

 nor are difficulties of a different kind wanting, under any hypo- 

 thesis we can form. It is not, however, necessary, with relation 

 to our present inquiry, to pursue this subject. Whether we 

 suppose all men to be of the same species, derived from a com- 

 mon centre, or of the same species, derived from different 

 centres, we equally reason on the assumption, that great 

 changes have been produced on the individuals by the influ- 

 ence of the agents affecting them. If we adopt the hypothesis 

 of one centre of dispersion for all the races of mankind, we 

 must suppose that change of place has converted the White 

 man into a Negro, and may convert the Negro into a White 

 man. If we suppose that the Primary Races of the species 

 were spread from different centres, as the Negro from some 

 part of intertropical Africa, the Caucasian from some country 

 of Western Asia, the Mongolian from some region of the East, 

 the Polynesian from one or more foci in the innumerable 

 islands over which he is spread, and the American from re- 

 gions proper to the great Continent to which he belongs, and 

 so on ; we do not, therefore, infer that these Races are not 

 severally subject to the influence of external agencies, and 

 capable of undergoing great mutations, under different con- 



