PATHOGENIC BACTERIA 1 15 



The bacillus of leprosy resembles the tubercle bacillus in its 

 staining properties, but gives up the carbol-fuchsin more easily 

 and is usually decolorized by the acid and alcohol. It is colored 

 blue by Pappenheim's method. 



Acid-fast bacilli have also been obtained from timothy grass, 

 butter, milk, manure, and the surfaces of animal bodies, but 

 differ from the tubercle bacillus in cultural characteristics. 



Biedert's Method of Collecting Bacilli. When the bacilli are 

 very few in a great quantity of fluid, as urine, pus, abundant 

 mucus, etc., Biedert advises to mix 15 c.c. of the fluid with 

 75 to 100 c.c. water and a few drops of potassium or sodium 

 hydroxid, then boiling until the solution is quite thin. It is 

 placed in a conical glass for two days, and bacilli with other 

 morphologic elements sink to the bottom of the glass; when 

 the supernatant liquid is decanted, the residue can be easily 

 examined. In this way bacilli were found that had eluded 

 detection examined in the ordinary manner. 



The centrifugal machine is used either in connection with 

 Biedert's sediment method or without, to obtain the solids sus- 

 pended in urine or serum. 



When the bacilli are so few in number in sputum or urine as 

 to make their detection difficult, and also when doubt exists as 

 to the identity of acid-fast bacilli found, several guinea-pigs 

 should be injected in the groin and smears and sections made 

 from the enlarged glands resulting. 



Phenol to Sediment Sputum. Pure phenol added to sputum 

 (about i part of the acid to 6 parts of sputum) will in a few 

 hours produce a coagulation and allow the sputum to be spread 

 evenly on the cover-glass, showing greater collections of bacilli. 



Without Cover-glass. Sputum can be spread and stained on 

 the glass slide without the use of a cover-glass, the oil of cedar 

 being placed directly on the stained sputum, and the oil-immer- 

 sion lens dipping into it. It is a rapid and cheap way; and 

 when a given case is to be studied daily, the method is useful. 



Pure Cultures from Sputum. Kitasato recommends the 

 thorough washing, changing the water ten times, of the small 

 masses found in the sputum of tuberculous persons. When 



