IMMUNITY. 597 



subsequent attacks. Cornet and Meyer suggest as 

 an explanation of this condition that the local le- 

 sion is so strictly isolated that a sufficient amount 

 of toxin does not escape into the circulation to 

 cause a general reaction, hence the formation of an- 

 titoxin or other antibodies is impossible. This ex- 

 planation seems inadequate, however, when we re- 

 member the strong antitoxic immunity which de- 

 velops in tetanus and diphtheria in spite of the lo- 

 calization of the bacteria. The results of artificial 

 immunization, in which unlimited amounts of 

 toxic material or bacilli may be injected without 

 the formation of satisfactory antitoxins, seem to 

 indicate that the toxic constituents of the tubercle 

 bacillus lack the power of causing the formation of 

 a strong antitoxin. 



In opposition to the prevailing opinion, certain 

 observers find ground for the belief that recovery 

 from local tuberculosis of the lymph glands, skin or 

 bones, actually does render the patients immune to 

 pulmonary consumption (Maragliano and others). 

 In early experiments Koch noted that when tuber- 

 cle bacilli were injected subcutaneously into 

 guinea-pigs which were suffering from general tu- 

 berculosis, the subcutaneous inoculation remained 

 as a local infection and not infrequently healed 

 after sloughing. The general infection would seem 

 to have increased local resistance. Although other 

 investigators failed to duplicate the observation of 

 Koch, this result is said to have suggested to him 

 the idea of active immunization as a cure for tu- 

 berculosis, a method subsequently practiced by 

 treatment with the various tuberculins. 



In the United States, Trudeau and de Schwein- 

 itz, and in Europe, Koch, Behring, Maragliano 



