136 LEPROSY AND SYPHILIS. 



gentian- violet for from twelve to twenty-four hours at the 

 room temperature, or for two hours at a temperature of 

 40 C. Wash a few minutes in absolute alcohol, then put 

 the section for some seconds into 1.5 per cent, solution of per- 

 manganate of potassium, pass rapidly (for one or two seconds) 

 into sulphuric acid solution, wash thoroughly in water, and 

 mount in xylol balsam. When stained by this method the 

 Bacillus smegmatis shows considerable resemblance to the 

 Bacillus tuberculosis, being of similar size and showing similar 

 refractive spots in the body of the cell. 



The Bacillus smegmatis is very difficult of cultivation, 

 growing only on media containing human serum or ascetic or 

 hydrocele fluid. 



As mentioned above, this bacillus has not been easily cultivated 

 artificially, and inoculations of animals have been barren of results. 



Streptococcus of Syphilis. 



Van Niessen, by collecting blood of syphilitic subjects, and al- 

 lowing same to coagulate in sterilized tubes, had been able from 

 the serum of this blood to cultivate a streptococcus which he 

 believed to be the etiological factor in syphilis. His experi- 

 ments, however, have failed of confirmation by others. 



QUESTIONS. 



When and by whom was the Bacillus leprse found ? Where is it found ? 



Describe the Bacillus leprx. Does it contain spores ? How is it grown arti- 

 ficially? How does it stain ? 



How do you differentiate Bacillus leprse, from the Bacillus tuberculosis by 

 staining ? What animals are susceptible to the infection ? 



Give a ready method for the diagnosis of a leprous ulcer or nodule, and give 

 a diagnosis of leprosy in a suspected case. 



Describe the Bacillus smeymatis of Lustgarten. Where is it found ? How 

 does it stain ? How decolorized ? How does it stain in tissue ? How does it 

 grow in artificial culture-media? 



Differentiate between Bacillus smegmatis and Bacillus tuberculosis. 



