PREFACE TO THE SECOND GERMAN EDITION. 



The first edition of "Immunity, Methods of Diagnosis and Therapy," 

 was, I am glad to say, favorably received. The book apparently fulfilled 

 a demand, as not quite two years have elapsed and a second edition is 

 required. An Italian translation by G. Volpino and an English edition 

 by A. L, Garbat have in the meantime appeared. A Spanish and a Rus- 

 sian publication are in preparation. 



During the last two years certain problems in this field have gained 

 greatly in importance, and therefore require more detailed consideration. 

 Special chapters have been allotted to tumor studies and to anaphylaxis. 

 Probably, even this treatise on anaphylaxis will by many be considered 

 too short. Without underestimating the distinct scientific value of the 

 very numerous articles being written on this subject, I feel that the 

 fundamental principles of anaphylaxis are still too theoretical and the 

 practical application still too limited, to warrant a more exhaustive re- 

 view in a practical book such as this. 



Chemotherapy, on the other hand, has attained such striking clinical 

 importance, that I have dwelt in length upon its development. As ever, 

 the practical elements are emphasized. My broad experience with 

 salvarsan has aided me in distinguishing the points of importance for the 

 practitioner. 



' Slight changes and additions have been scattered throughout the book. 



I hope that this second edition will add new friends and retain the 

 old ones. 



JULIUS CITRON. 



Vll 



