INTRODUCTION IS 



bacterial growth. Supplementing the work of Traube 

 and Gscheidlen, in 1887, Buchner showed the specific- 

 ity of the bactericidal properties of blood-serum. 



In 1888, Roux and Yersin, and Kitasato dis- 

 covered the toxins respectively of diphtheria and 

 tetanus. In 1890, Behring discovered antitoxin in 

 the serum of animals immunized against the toxin of 

 diphtheria, thus furnishing the first antitoxic serum. 

 In the same year, with the collaboration of Kitasato, 

 immunity to tetanus was conferred on mice from the 

 serum of rabbits inoculated with tetanus toxin. In 

 the following year with Wernicke, he immunized other 

 animals with antidiphtheric serum. Behring, there- 

 fore, discovered the whole principle underlying serum 

 therapy in its relationship to modern therapeusis and 

 serological studies, and became thereby its honored 

 founder. 



The following year Ehrlich demonstrated anti- 

 bodies in the serum of animals inoculated with vege- 

 table poisons, as ricin, abrin and crotin, and three 

 years later Calmette claimed similar results with snake 

 venom. 



Although it was recognized, even before Behring' s 

 discovery, that the serum of animals inoculated with 

 certain bacteria possessed a specific anti-infectious 

 effect or protection, it was about this time, 1892, that 

 Metchnikoff called attention to a particular substance, 



