SYPHILIS. 289 



account of the mode in which they are arranged in the 

 diseased tissues. 



The method of staining successfully employed by Lust- 

 garten consists in staining the sections in aniline gentian 

 violet solution, and subsequent decolourisation by means 

 of a solution of permanganate of potash, the dioxyde of 

 manganese the product of the reduction process being 

 subsequently removed from the sections by sulphurous 

 acid ; after this treatment the sections appear quite 

 colourless, with the sole exception of the syphilis bacilli. 



Lustgarten's method may be shortly described as Method of 

 follows:- 



The sections remain in a mixture of 100 parts of aniline 

 water, and 11 parts of concentrated alcoholic gentian violet 

 solution for 12 to 24 hours at the ordinary temperature, 

 or for 2 hours at the body temperature; they are then 

 washed in alcohol, then for about 10 seconds in a 7-| per cent, 

 watery solution of permanganate of potash ; in that fluid the 

 preparations become covered with brownish flakes of dioxyde 

 of manganese. By placing them for a short time in a watery 

 solution of sulphurous acid, the dioxyde of manganese is 

 reduced, dissolved, and washed away ; the sections are then 

 washed in distilled water, and if they have not been suffi- 

 ciently decolourised, the process is repeated; as a rule it is 

 only after repeating it three or four times that a good result is 

 obtained. Finally the section is dehydrated in alcohol, and 

 then placed in the usual manner in oil of cloves and Canada 

 balsam. Cover glass preparations are treated in like manner, 

 with the exception that, after the action of the violet, water, 

 and not alcohol, is employed as the first decolourising agent. 

 Not only is the tissue decolourised by this plan, but also all 

 bacteria, with the exception of the syphilis bacilli, and the 

 bacilli of leprosy and tubercle ; the syphilis bacilli may, how- 

 ever, be distinguished from the latter by the fact that they 

 are quickly decolourised by treatment with hydrochloric acid 

 or nitric acid. 



The bacilli found in syphilitic new formations are Morphological 

 usually bent, slightly S-shaped, and on an average 4J cliaracters - 

 p. long ; they often show a slight knob-like swelling at 

 the ends ; their contour is not quite uniform, but it is 

 more or less wavy, or indented at parts. When highly 

 magnified we can see, in the dark blue stained bacillus, 

 clear oval refracting spots two to four in number and 



19 



