BACILLI IN CHRONIC INFECTIOUS DISEASES. 403 



to be spores. The bacilli are not found free in the tissues, but are enclosed 

 in cells of a round-oval or polygonal form, which are said to be about double 

 the size of a white blood corpuscle. The bacilli are not numerous, and very 

 commonly only one or two are found in a single cell, but groups of six or 

 eight may sometimes be seen, especially upon the margins of a syphilitic 

 lesion, and in the tissues in the immediate vicinity of the infiltration, which 

 show but little change or are apparently healthy (Lustgarten). 



The presence of these bacilli in syphilitic lesions was demonstrated by 

 Lustgarten by the following staining method : The thin sections are placed 

 in the Ehrlich-Weigert gentian-violet solution (one hundred parts aniline 

 water, eleven parts saturated alcoholic solution of gentian violet) for from. 

 twelve to twenty four hours at the room temperature, and two hours in the 

 incubating oven at 40 C. The sections are then thoroughly washed in alco- 

 hol and placed for ten seconds in a 1.5-per-cent solution of potassium per- 

 manganate; in this solution a precipitate of peroxide of manganese is 

 formed, which adheres to the section; this is dissolved and washed off in a 

 dilute aqueous solution of pure sulphuric acid ; the sections are then washed 

 in water, and, if not completely decolorized, are returned for a few seconds to 

 the permanganate solution and again washed off in the acid; it may be 

 necessary to repeat this operation three or four times. Finally the sections 

 are dehydrated and mounted in balsam in the usual manner. Cover-glass 

 preparations are made in the same way, except that, after being- taken from 

 the staining solution, they are washed off in water instead of in alcohol. 



Another method of staining, recommended by De Giacoma, consists in 

 placing the sections for twenty -four hours in aniline-water-fuchsin solution 

 (cover-glass preparations may be stained in the same solution, hot, in a few 

 minutes), then washing them in water, and decolorizing in a solution of per- 

 chloride of iron first in a dilute and then in a saturated solution. 



The method of staining employed by Lustgarten serves to differentiate 

 his bacillus from many other microorganisms, but not from the tubercle ba- 

 cillus and the bacillus of leprosy, which, as he pointed out, may be stained 

 in the same way. And it has since been shown by Alvarez and Tavel, and 

 by Matte rstock, that in smegma from the prepuce or the vulva, bacilli are 

 found which have the same staining- reaction and are similar in their mor- 

 phology to the bacillus of Lustgarten. This by no means proves that the 

 smegma bacilli found under the prepuce of healthy persons are identical 

 with the bacilli found by Lustgarten and others in sections of tissues involved 

 in syphilomata. In the absence of pure cultures and inoculation experiments 

 it is impossible to establish identity, however similar may be the characters 

 referred to. Several well-known pathogenic bacilli resemble quite as closely 

 in these particulars other bacilli which have, nevertheless, been differentiated 

 from them by culture and inoculation experiments. We may mention 

 especially in this connection the bacillus of diphtheria, as obtained from the 

 pseudo-membranous exudation in a genuine case of this disease, and the 

 pseudo diphtheria bacilli found by Eoux and Yersinin the fauces of healthy 

 children. On the other hand, since it has been shown that similar bacilli 

 are common in preputial srnegma, we cannot attach great importance to the 

 finding of Lustgarten's bacillus in primary syphilitic sores ; and it has not 

 been found in sufficient numbers, or with sufficient constancy, by those who 

 have searched for it subsequently to the publication of Lustgarten's inves- 

 tigations, to give strong support to the view that it is the specific infectious 

 agent in syphilis. Baumgarten, who has searched in vain for Lustgarten's 

 bacillus in uncomplicated visceral syphilomata, suggests that the bacilli 

 found occasionally in such lesions were perhaps tubercle bacilli and repre- 

 sented a mixed infection. As the bacillus under consideration has not been 

 obtained in cultures, we have no information as to its biological characters 

 and pathogenesis. 



THE SYPHILIS BACILLUS OF EVE AND LINGARD. 

 Eve and Lingard (1886) report that they have obtained in cultures from 



