PREFACE. Vli 



historical sketches prefixed, with references both to other papers 

 in this volume and to many which have been omitted. Read 

 with these aids, and with the help of the table of contents and 

 index, this volume will, it is believed, suffice to give clear and 

 connected notions of the author's views on the various questions 

 herein discussed. 



T. S. H. 

 BOSTON, Mass., September, 1874. 



