PREFACE TO THE THIRD EDITION 



Several changes have been made in the text of the 

 second edition. - These changes were outlined by the 

 author and preserved as marginal notes in a copy used 

 by him in the class-room. In some cases these notes 

 have been inserted without change, in others where ab- 

 breviated they have been amplified according to what 

 is believed to be the intent of the author. This assump- 

 tion is founded on intimate association with the author 

 in his work in the preparation of the first edition and 

 in later class work. 



In making changes an effort has been made to ap- 

 proach as closely as possible to the style of the text. 



FREDERIC CRANEFIELD. 

 Madison, Dec., 1905. 



