6 APPLIED IMMUNOLOGY 



in patients suffering from chronic infections, particu- 

 larly, and also in certain acute conditions, the number 

 of specific antibodies may be materially increased and 

 convalescence shortened or recovery insured by artifi- 

 cial inoculation employing homologous bacteria. This 

 result may be achieved by injecting the bacteria with a 

 hypodermic syringe directly into the tissues, or by 

 carefully regulated and graduated auto-inoculation, 

 by manipulations, as massage, hyperemia, etc., of the 

 infected area. The discovery of the feasibility of pro- 

 ducing auto-inoculation in patients afflicted with a 

 localized infection was one of great magnitude and 

 vital consideration in the study and correct interpreta- 

 tion of infection and immunity, particularly in connec- 

 tion with bacterin therapy. By its utilization difficult 

 diagnoses have been established, successful treatment 

 conducted in selected cases and in constitutional dis- 

 eases, clinical interpretations correctly deduced, and 

 proper treatment applied (see Chapter XXI) . It is 

 evident, therefore, that when an individual recovers 

 from an infectious disease he enjoys for an indefinite 

 time immunity against repeated attacks due to the 

 same infective organism. It can also be readily under- 

 stood that immunity against particular diseases can be 

 conferred by artificial inoculation, using the specific 

 bacteria, viruses, etc. (prophylactic inoculation or 

 vaccination). 



