G 



PREFACE TO THE THIRD EDITION. 



ANOTHER call for a new edition of Infection and Immunity has 

 given the author the opportunity to introduce a certain amount of 

 new matter, which seemed of especial interest to the student of this 

 fascinating subject. The recent advances in the study of Abder- 

 halden's protective ferments and the associated technique have thus 

 received detailed consideration. The section on the Wassermann 

 reaction has been almost entirely rewritten. Attention has been 

 directed to the manner in which the danger from anaphylactic shock 

 during serum treatment may be reduced to a minimum. Emphasis 

 has been given to the important observation of Schick and his 

 collaborators, that it is possible through the aid of an allergic skin 

 reaction to recognize those individuals, whose blood normally con- 

 tains a quantity of diphtheria antitoxin sufficient for purposes of pro- 

 tection. The same is true of the observation of Ashhurst and John, 

 that by suitable technique more encouraging results may be obtained 

 in the treatment of tetanus, after symptoms of the disease have once 

 developed, than heretofore. The possibility has been pointed out 

 that by means of vaccine treatment, Hodgkin's disease may be 

 advantageously influenced, etc. 



In addition a bibliography has been introduced in which the 

 student who may be interested in the historical development of the 

 subject or in the details of modern immunological research, will find 

 gathered together the more important references. For obvious 

 reasons this collection is in no sense complete, and practically repre- 

 sents those papers, upon a study of which the volume as a whole is 

 based. 



I would emphasize again that Infection and Immunity was originally 

 written as an introduction to this most intricate subject, and to 

 serve as a guide to further reading. So many details of technique, 

 however, have since been added, that the book might now serve as 

 a basis for a course of systematic instruction in Immunology in our 



25>72 



