Preface 



The object of this book is to furnish the busy 

 practitioner with an outline of the historic de- 

 velopment of medicine; to give him many im- 

 portant facts which may be of use in his pro- 

 fessional work or which may be desirable for 

 him to know as a part of his medical education ; 

 and to provide him with a handy reference com- 

 pendium on vaccine and serum therapy. 



In submitting this work to the medical pro- 

 fession, our aim has been to state concisely and 

 accurately the present understanding concern- 

 ing the clinical application and value of im- 

 munology; and to present the subject in such 

 a manner as to be of the most assistance to the 

 practitioner. 



Tho scope of this little volume is not intended 

 to embrace a complete description of all biologic 

 preparations used in the practice of medicine; 

 but only such products as are prepared by our 

 laboratories have been discussed. An enormous 

 literature pertaining to biologies has accumu- 



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