PREFACE TO THE FIRST EOmON 9 



advances, referring the reader to tlie ,s])eeial treatises for the general 

 and historical discussions. 



It is with the greatest pleasure that I acknowledge my indebtedness 

 to many colleagues in the University of Chicago, who have kindly read 

 the sections of my manuscript tliat touch upon tlieir own special fields, 

 and whose criticism and advice have been of the greatest assistance ; 

 their number alone prevents my thanking them by name. Most par- 

 ticularly, however, must I express my debt to my former instructor, 

 Professor Lafayette B. jMendel, of Yale University, whose kindly 

 criticism and suggestions have been of inestimable value. For con- 

 stant assistance in the preparation of the manuscript, and for the 

 revision of the bibliography, I am indebted to my wife. 



H. G. W. 



