250 TEXT-BOOK OF BACTERIOLOGY. 



alcohol, and if he further clarified not with oil of cedar or cloves, 

 but with xylol, he saw, as he maintained, that the agglomerations 

 of bacteria which had always been taken for lepra cells were in 

 fact no cells at all, but only a deception caused by the wrong treat- 

 ment of the object, and that the supposed cells were only free, ball- 

 shaped assemblages of rod-cells in enlarged cavities of the lymphatic 

 vessels. 



We know, however, that just complaints are made against the 

 drying system on account of its destroying the transparency of the 

 tissue, and it has been suggested that Unna's lymph passages are 

 nothing but artificial productions. In fact, the greatest authori- 

 ties on the lepra question, Neisser, Touton, Arning, etc., all persist 

 in the opinion that the chief mass of the rod-cells lies within the 

 lepra cells, while a certain portion of them is also to be found dis- 

 tributed in the tissue. 



V. SYPHILIS BACILLUS. 



If important factors are wanting in lepra to positively prove 

 bacilli the cause of the disease, this is still more the case in another 

 disease which somewhat resembles tuberculosis and lepra, namely, 

 syphilis. 



As everybody is aware and as experience abundantly shows, 

 syphilis is a very infectious and easily-transmissible disease. But 

 we know hardly anything about the sources of its infectious nature 

 and the causes of its peculiar phenomena. Although we might be 

 inclined to suspect a bacterium as the bearer of its virus, yet our 

 knowledge is not yet sufficient to enable us to prove the correctness 

 of such a supposition. 



The first approach to a satisfactory explanation is perhaps to 

 be found in the observations published by Lustgarten a few years 

 since. He announced that he had succeeded, by means of a special 

 staining process, in finding a particular species of bacillus in syph- 

 ilitic lesions and the secretion of syphilitic sores, the occurrence of 

 which was restricted to these places named, and which was, there- 

 fore, peculiar to syphilis. 



The thinnest possible sections must be treated as follows ac- 

 cording to Lustgarten: First they are to be stained for twelve 

 to twenty-four hours at ordinary room temperature with anilin- 

 gentian-violet, and then the process is continued for about two 

 hours at 40° C. in the incubator; next they are washed for several 

 minutes in absolute alcohol, and placed in a 1^^ aqueous solution of 

 permanganate of potash for about ten seconds, and at last well 

 rinsed in distilled water. 



