PREFACE 



Despite the enormous strides, experimentally and 

 clinically, that have marked the progress in serological 

 and bacteriological research in medicine for the past 

 quarter of a century, leading to results of the highest 

 clinical value diagnostically and therapeutically, three 

 facts stand out in bold relief: First, that the average 

 practitioner's knowledge of biological therapeusis is a 

 " dangerous thing " because he does not " drink deep 

 of the Pierian spring " ; second, insufficient practical 

 instruction is given to students in our medical schools 

 in view of the prevalent practice of this mode of diag- 

 nosis and treatment; third, authors have sadly neg- 

 lected to give a concise presentation of immunology in 

 its entirety for the practical grasp and comprehension 

 of students and practitioners. The vast majority of 

 standard works on the subject of " immunity " are 

 exhaustive treatises on the experimental and theoreti- 

 cal phases of the subject and are often unintelligible 

 and of little value to the average practicing physician. 



The result of the above has been that pharmaceuti- 

 cal firms have assumed the function of the Department 

 of Therapeutics in our medical colleges, not always 

 impartially and to the best interests of medical science. 



