722 Syphilis 



incubating oven at 37C. for from three to five days. Finally, it is washed in 

 water and placed in a solution of pyrogallic acid, 2 to 4 grams; formol, 5 cc.; 

 distilled water, 100 cc., and kept in the dark, at room temperature, from twenty- 

 four to seventy-two hours, then washed in distilled water, embedded in paraffin, 

 and cut. The treponemata are intensely black, the tissue yellow brown. The 

 sections are finally stained with (a) Giemsa's stain for a few minutes, then 

 washed in water, differentiated with absolute alcohol containing a few drops of 

 oil of cloves, cleared with oil of bergamot or xylol, or (&) concentrated solution of 

 toluidin blue, differentiated in alcohol containing a few drops of Unna's glycerin- 

 ether mixture, cleared in oil of bergamot, then in xylol, and mounted in Canada 

 balsam. 



This method was later improved by Levaditi and Manouelian* 

 by the addition of 10 per cent, of pyridin to the silver bath just 

 before the block of tissue is put in, and by using for the reducing 

 bath a mixture of pyrogallic acid, acetone, and pyridin. 



The details are as follows: Fragments of organs or tissues i to 2 mm. in thick- 

 ness are fixed for twenty-four to forty-eight hours in a solution of formalin 10: 100, 

 then washed in 96 per cent, alcohol for twelve to sixteen hours, then in distilled 

 water until the blocks fall to the bottom of the container. They are then impreg- 

 nated by immersion in a bath composed of a i percent, solution of nitrate of silver, 

 to which, at the moment of employment, 10 per cent, of pyridin is added. Keep 

 the blocks immersed in this solution at room temperature for two or three hours, 

 and at 5oC. for four or six hours, then wash rapidly in a 10 per cent, solution of 

 pyridin, and reduce in a bath composed of 4 per cent, pyrogallic acid, to which, at 

 the moment of using, 10 per cent, of pure acetone and 15 per cent, (total volume) 

 of pyridin are added. The reduction bath must be continued for several hours, 

 after which the tissue goes through 70 per cent, alcohol, xylol, paraffin, and sec- 

 tions are cut. The sections, fastened to the slide, are stained with Unna's blue 

 or toluidin blue, differentiated with glycerin-ether, and finally mounted in Canada 

 balsam. 



Distribution. -The Treponema pallidum is not known in nature 

 apart from the lesions of syphilis. It has now been found in all 

 the lesions of this disease and in the blood of syphilitics in larger 

 or smaller numbers. The discovery has greatly modified our ideas 

 of the tertiary stage, for the demonstration of the organisms in its 

 lesions shows them to be undoubtedly contagious. The greatest 

 number of the organisms are found in the tissues -especially the 

 liver of still-born infants with congenital syphilis. 



Cultivation. The cultivation of the treponema was first at- 

 tempted by Levaditi and Mclntosh,f who, deriving the organism 

 from an experimental primary lesion in a monkey (Macacus rhesus), 

 carried it through several generations in collodion sacs inclosed in 

 the peritoneal cavity of other monkeys (Macacus cynomolgus) 

 and in the peritoneal cavity of rabbits. They were unable, how- 

 ever, to secure the treponema in pure culture, having it continually 

 mixed with other organisms from the primary lesion. In the 

 mixture, however, they were able to maintain it for generations 

 and study its morphology and behavior. During cultivation its 

 virulence was lost. 



Schereschewskyf endeavored 'to cultivate the treponema by 



' " Compt.-rendu de la Soc. de Biol. de Paris," 1906, LVIII, p. 134. 

 ' "Ann. de ITnst. Pasteur," 1907, p. 784. 

 J "Deutsche med. Wochenschrift," 1909, xxxv, 835, 1260, 1652. 



