436 Chapter XIV 



Ebing^ has resolved this question by the application of the law of 

 acquired syphilitic immunity. The inoculation of the syphilitic virus 

 into ten persons attacked by general paralysis was followed by no 

 chancre at the seat of inoculation and by no other primary or 

 secondary symptom of syphilis. The patients with general paralysis 

 present a real immunity against these symptoms ; consequently 

 general paralysis is a tardy manifestation of syphilis. 



The acquired immunity against re-inoculation by the syphilitic 

 virus is established immediately after the end of the period of incuba- 

 tion of the first infection, and is of lifelong duration 2. Besides this 

 very special and, so to speak, partial immunity, there exists in syphilis 

 a second form of acquired immunity which is of a more general 

 nature. According to the law known as the law of Baumes-Colles, 

 the mother who suckles her infant, hereditarily infected with syphilis 

 through the father only, enjoys a real anti-syphilitic immunity. 



In tuberculosis the few facts of acquired immunity that have 

 been observed present a certain analogy with those bearing on im- 

 munity in syphilis. A large number of well-observed facts demon- 

 strate that a person who has suffered from scrofula or has manifest 

 symptoms of tuberculosis properly so called, cannot count upon an 

 immunity against pulmonary phthisis. It might, then, be supposed 

 that no acquired refractory condition exists in connection with this 

 disease. Koch^ has clearly demonstrated, however, that tuberculous 

 guinea-pigs, into which the bacilli of tuberculosis have been intro- 

 duced subcutaneously, react against these bacilli in a very special 

 manner. The presence of these micro-organisms immediately sets up 

 an active inflammatory process at the point of inoculation ; this brings 

 about the expulsion of the bacilli with the exudation ; a voluminous 

 slough is developed, which, when shed, carries with it a large number 

 of bacilli, a process followed neither by the formation of a permanent 

 ulcer nor by hypertrophy of the neighbouring glands. As in syphilis, 

 the animal has acquired immunity against re-infection by the tuber- 

 [458] culous virus, which, however, in no way prevents the first inoculation 

 from becoming generalised and setting up a fatal tuberculosis of 

 almost all the organs. Koch's observations, which have served as the 

 basis of hiB researches on tuberculin, have been confirmed by other 



^ Address given at the Xllth International Congress of Medicine at Moscow, 

 1S97. 



^ See Hudalo, Ann. de dermat. et de si/ph., Paris, 1891, 1. 11, pp. 353, 470. 

 3 Deutsche med. Wchnschr., Leipzig, 1891, S. 101. 



