BACILLI IN CHRONIC INFECTIOUS DISEASES. 495 
the ends often present slight knob-like swellings; the length is from three 
and one-half / to four and one-half “, and the diameter is from 0.25 to 0.3 u. 
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 
Fic, 124. Fic. 125. 
Fic. 124.—Migrating cell containing syphilis bacilli. CLustgarten.) 
Fic. 125,—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, reeommended 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 microdrganisms, 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 
