Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. This text has been in process of growth at the University of Chicago since 1913. At that time a synopsis of the first nine chapters was printed. This was followed, in 1916 - 1 7, by the completed work of the first fifteen chapters. Chapters xvi-xix were added and used in class work during 1918 and 1919.
