DESCRIPTIONS OF PATHOGENIC BACTERIA. 203 



tivate the germ have not succeeded. Arning 

 successfully infected a criminal condemned to 

 death at Honolulu, and Melcher and Ortmann 

 seem once to have obtained an infection in 

 rabbits. 



In syphilis, Lustgarten has, by staining, dem- 

 onstrated special rod bacteria both in primary 

 syphilitic manifestations and in the inherited 

 disease. This is really the only fact that sup- 

 ports the view that these bacteria are the cause 

 of syphilis. Bacteria occur in the secretion of 

 the prepuce which, in consequence of being 

 impregnated with fat, stain in a manner simi- 

 lar to Lustgarten's bacteria ; the wax of the 

 outer ear imparts to various bacteria a similar 

 peculiarity of stain. 



It is by no means easy to distinguish be- 

 tween the bacteria of tuberculosis, leprosy, 

 syphilis and smegma by methods of staining. 

 The tubercle bacilli, by virtue of a mucous- 

 like substance occurring in the membrane 

 (isolated by Weyl), possess a remarkable re- 

 sistance to acids. Ehrlich was the first to 

 make use of this property in differential stain- 

 ing. If these bacteria are stained red with a 

 mordant stain, as with carbolic acid fuchsin or 

 aniline water fuchsin, the stain resists sub- 

 sequent treatment with strong mineral acids, 

 while other bacteria as well as cell-nuclei are 



