PREFACE TO THE FOURTH EDITION 



In the new edition of General Therapeutics the chapters on 

 chemotherapy, protective vaccination, and disinfection have been 

 rewritten. The "therapia sterilisans magna" of Ehrlich has become 

 of great importance to veterinarians, although at the beginning of 

 its introduction the judgment concerning it was too optimistic 

 (contagious pneumonia!). Considerable development has also 

 occurred in the last ten years in the field of protective vaccination. 

 The more complete vaccination statistics now available make pos- 

 sible a more exact judgment concerning the value or worthlessness 

 of the different immune sera. More recent observations have 

 compelled a partial modification of our views in regard to disinfec- 

 tion; this is especially true in respect to preliminary disinfection 

 and its relation to cleaning. The new German veterinary sanitary 

 law has been included in the revision. The reader will also find 

 numerous changes and improvements in other chapters. 



E. Frohner. 

 Berlin. 



