TREPONEMATA 519 



Primary Lesion. Clean the surface of the chancre with brisk rub- 

 bing, then make an abrasion in the skin deep enough so that there is 

 an exudation of serum. Films are prepared from this exudate. 



Secondary Lesion; Mucous Patches and Papules. Material is 

 removed from the mucous patch after cleaning the surface, or from 

 the papule by slight curetting. If the material thus obtained is too 

 dense to spread readily it may be macerated in a drop or two of 

 sterile ascitic fluid. 



1. Morphology. The organisms may be seen in the living state 

 with the dark-ground illuminating apparatus. The juice of a mucous 

 patch or primary lesion is examined directly and the organisms appear 

 on a black background as light yellowish closely coiled spirals, which 

 are actively motile. The presence of Spirocheta (Treponema) refrin- 

 gens must be borne in mind, this organism being frequently associated 

 with Treponema pallidum. The former is thicker than Treponema 

 pallidum, and the spirals are less numerous and coarser. 



India Ink Method. The juice from a chancre or mucous patch is 

 intimately mixed with india ink 1 and a cover glass placed over the 

 mixture. The organisms appear as white spirals against a black 

 background. 



Other Staining Methods. The material collected as above is spread 

 on slides in thin layers and stained either by Schaudinn and Hoffmann's 

 original method or by the silver impregnation method. 



Method of Schaudinn and Hoffmann. The films are fixed for fifteen 

 to thirty minutes in absolute methyl alcohol or for a few seconds 

 in the vapor of osmic acid, then they are stained from one to three 

 hours in the following solution, which must be freshly prepared each 

 time; Giemsa's solution, 10 drops; 1 per cent, aqueous solution of 

 potassium carbonate, 10 drops; distilled water, 10 c.c. The films, 

 after staining, are washed in distilled water. If overstaining has 

 taken place the film may be left in distilled water for some minutes 

 until a sufficient amount of stain has been removed. The preparation 

 is then dried and examined. The organisms appear as purple or violet 

 spirals on a bluish background. 



Silver Impregnation Method. 2 Not generally used. 



2. Cultural Diagnosis. Not practical for routine. 



3. Serum Diagnosis. (For Technic see page 161.) 



1 Burri, Wien. klin. Wchnschr., July 1, 1909. 



2 See Levaditi, Compt. rend, de Soc. de Biol., 1905, lix, 326, for details. 



