V1U PEE PACE. 



pages, i would say that, amidst much that is familiar, 

 fchey will find here and there some facts which may 

 be new to them, as well as some original suggestions 

 and conclusions as to the relations of things, which 

 though stated in familiar terms, I have not advanced 

 without due consideration of a wide range of facts. 

 To the general reader I have endeavoured to present 

 the more important results of geological investigation 

 divested of technical difficulties, yet with a careful re- 

 gard to accuracy of statement, and in such a manner 

 as to invite to the farther and more precise study of 

 the subject in nature, and in works which enter into 

 technical details. I have endeavoured as far as pos- 

 sible to mention the authors of important discoveries : 

 but it is impossible in a work of this kind to quote 

 authority for every statement, while the omission of 

 much important matter relating to the topics discussed 

 is also unavoidable. Shortcomings in these respects 

 must be remedied by the reader himself, with the 

 aid of systematic text-books. 



J. W. D. 



McGiLL COLLEGE, MONTREAL, 

 January, 1873. 



