PREFACE TO THE SECOND EDITION 



THE purpose and general plan of this volume remains unchanged 

 in this edition. I have endeavored- to make it a practical treatise for 

 medical students, practitioners, and laboratory workers by setting 

 forth theories and opinions simply and plainly, and devoting particular 

 attention to technic and the practical phases and application of the 

 subjects considered; I hope that this edition will receive the same gen- 

 erous recognition as its predecessor. 



Additions and alterations have been made throughout; special 

 attention has been given the subject of focal infection; the Schick toxin 

 test for immunity in diphtheria and active immunization in diphtheria 

 with toxin-antitoxin mixtures; complement-fixation in tuberculosis and 

 other bacterial infections and a quantitative Wassermann reaction 

 based upon my studies with the co-operation and assistance of Dr. 

 Claude P. Brown, Dr. Toitsu Matsunami, and Dr. Berta Meine, aiming 

 to standardize this important test. The chapters on anaphylaxis have 

 been revised and particular attention given the subject of anaphy lactic 

 skin reactions. Lange's colloidal gold reaction has been included. 

 The chapter on the treatment of various infections with bacterial vac- 

 cines has been enlarged and the non-specific activity of bacterial vac- 

 cines discussed. The section on the treatment of certain of the acute 

 infectious diseases, and particularly acute anterior poliomyelitis, with 

 the serum of convalescents and normal persons has been amplified; 

 blood transfusion has been included. Special attention has been de- 

 voted to the chapter on Chemotherapy, and the results of the studies of 

 Dr. Jay F. Schamberg, Dr. George Raiziss, and the author bearing upon 

 the toxicity of salvarsan and its congeners and the reactions following 

 their administration have been included and discussed. The subject 

 of Bacterial Chemotherapy, which promises much in the future, has been 

 amplified from the theoretical and technical viewpoints. 



The section on Experimental Infection and Immunity remains as 

 part of the volume instead of forming a separate book; experience has 

 shown that this is a good plan, and enables the student doing more or 

 less independent work to consult the text for directions and discussions. 



J. A. K. 

 MCMANES LABORATORY OF EXPERIMENTAL PATHOLOGY, 



UNIVERSITY OF PENNSYLVANIA, October, 1917. 



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