CHAPTER V. 

 SYPHILIS. 



ALTHOUGH syphilis is otherwise well known, its specific 

 cause has not yet been discovered. Whether it be due to 

 a protozoan parasite, as has long been supposed, and the 

 discovery of which has recently been claimed by Max 

 Schiiller, or to some bacillus such as has been described 

 by Lustgarten or van Niessen, future investigation must 

 decide. The fact that the disease was not successfully com- 

 municated to any of the lower animals until 1903, when 

 Metschnikoff and Roux* succeeded in infecting a chim- 

 panzee, and this work was confirmed by Lassar,| has 

 markedly interfered with its successful etiologic investiga- 

 tion. 



Metschnikoff and RouxJ also have since found it possible 

 to infect macaques with syphilis, though in them the disease 

 was always mild and local. Passing the virus from the 

 macaques to the chimpanzee, they found it attenuated. 



BACILLUS OF LUSTGARTEN. 



General Characteristics. An elongate bacillus known only in 

 preparations stained by a peculiar method and susceptible of neither 

 cultivation nor successful animal inoculation. Very probably identical 

 with the smegma bacillus when in the discharges, and with the tuber- 

 cle bacillus when in internal lesions. 



In 1884 and 1885 Lustgarten published a description ot 

 peculiar bacilli which he found by staining syphilitic tissues 

 by a peculiar method and assumed to be the cause of the 

 disease. The method of staining is somewhat complicated, 

 and requires that sections of tissue be stained in Ehrlich's 

 anilin water gentian-violet solution for from twelve to 



*"Ann. de 1'Inst. Pasteur," Dec., 1903, p. 809. 

 t"Berl. klin. Wochenschrift," 1903, p. 1189. 

 J"Annales," Jan., 1904. 



" Wiener med. Wochenschrift," 1884, p. 47, and "Wiener med. 

 Jahrb.," 1885. 



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