272 ' THE AMERICAN MONTHLY [Sept. 



Smegma Bacillus. 



By PHILIP JAISOHN, M. D. 



WASHINGTON, D. C. 



Of late years the practitioners can make a positive 

 diagnosis of tuberculosis by examining microscopically 

 the discharges of the suspected patient such as sputum, 

 pus or urine as the case may be. The main diagnostic 

 point of tubercle bacillus is that it retains the carbol- 

 fuchsin stain even after treating it with an acid solution. 

 On account of this peculiarity we can readily recognize 

 it, as all other micro-organisms lose the red color as soon 

 as an acid solution is applied. 



There are numerous methods of staining tubercle 

 bacillus, but the easiest and surest are those of Ziehl- 

 Neelsen and Frankel-Grabbett. However, every method 

 has one common object in view, that is to either de- 

 colorize or counter stain all other micro-organisms so 

 that the red stained tubercle bacillus will stand out con- 

 spicuously in the field. Now there is another bacillus 

 which has the same peculiarly, namely, the smegma 

 bacillus. This organism had undoubtedly misled many 

 a microscopist in the past and will do so in the future, 

 if one's attention is not called to it. Prof. Welch of 

 Johns Hopkins Hospital first called my attention to the 

 fact, and recently I made some study on the subject. I 

 obtained a large quantity of smegma from some negro 

 patients who have no tubercular history, and made a 

 number of cover slip preparations from this material, 

 and stained them just like staining for Tubercle bacil- 

 lus, (Modification of Ziehl-Neelsen's method). The field 

 under the microscope is identical with that of tubercle 

 bacillus, except the red-stained bacilli in the blue back 

 ground are somewhat broader and more curved than 

 tubercle bacilli. Although if I had not known that it 

 was smegma I would not have noticed this difl"erence. I 



