VI PREFACE. 



bear the stamp of originality, and lie escapes the very con- 

 siderable danger of being a mere compiler. 



While correcting the proof-sheets, I had the advantage or 

 reading Mr. Mitchell's work on "Evolution and Dissolution," 

 and this suggested some of the remarks on this subject 

 contained in Chap. XII. , Part I. My indebtedness to this 

 author was, through oversight, not acknowledged in the text ; 

 but with this exception I have, I believe, in all cases acknow- 

 ledged the authorities I have made use of. 



H. C. 



