BACILLI IN CHRONIC INFECTIOUS DISEASES. 423 



the ends often present slight knob -like swellings ; the length is from three 

 and one-half p to four and one-half /", and the diameter is from 0.25 to 0.3 p. 

 With a high power the contour is seen to be not quite regular, but wavy in 

 outline, and bright shining spaces in the deeply stained rods may be ob- 

 served ; these, from two to four in a single rod, are believed by Lustgarten 

 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 



FIQ. 126. FIG. 127. 



FIG. 126. Migrating cell containing syphilis bacilli. (Lustgarten. ) 

 FIG. 127 Pus from hard chancre containing syphilis bacilli. (Lustgarten.? 



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 Giacorna, 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 Matterstock, 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 



