PREFACE TO THE SECOND EDITION. 



SCIENTIFIC activity in the domain of clinical bacteriology 

 has been not less pronounced than fruitful during the 

 period that has elapsed since the appearance of the first 

 edition of this book. By including the numerous results 

 of recent investigation the size of the present volume has 

 been considerably increased. Chapters have been added 

 on Plague and Botulism, and those on Immunity, Diph- 

 theria, Typhoid Fever, Actinomycosis, Examination of Air 

 and of Water, and others, have been radically revised ; and 

 in all other sections numerous changes and additions have 

 been made. 



We believe the work adapted to the present position of 

 bacteriologic knowledge, and hope that this edition may 

 have the same friendly reception accorded the first edition. 



THE AUTHORS. 



