n APPLIED IMMUNOLOGY 



mote research along this line. Schwann showed the 

 relationship between decomposition of organic bodies 

 and microorganisms. This was supplemented by 

 Pasteur's work on fermentation and the yeast fungus. 

 In 1863 Davaine pointed out that certain bacilli de- 

 scribed in the blood by him thirteen years before were 

 the causative factors in anthrax. Thirteen years later, 

 Koch succeeded in growing these bacilli on an artificial 

 medium in pure culture, and anthrax was reproduced 

 in animals. 



The next problem was to attenuate the bacteria, 

 that is, preserve their identity and life, at the same 

 time reducing their virulence, so that inoculation would 

 not result fatally. In 1880, Pasteur succeeded in 

 preparing a " vaccine " from attenuated anthrax 

 bacilli and inoculated sheep, thereby rendering them 

 immune. 



In 1885, after much animal experimentation, 

 Pasteur inoculated the first human subject against 

 rabies. The etiological microorganism of the virus of 

 this disease is still undetermined and the procedure of 

 antirabic inoculation has undergone no material 

 change. 



Thus far the belief prevailed that immunity oc- 

 curred only as the result of recovery from disease. 

 Salmon and Smith at this time demonstrated that 

 immunization could be produced by the products of 



