PATHOGENIC BACTERIA. 



101 



It will only be necessary to describe those methods principally 

 in use ; and as the examination of sputum for bacilli is of so 

 frequent an occurrence, and so necessary, it is well to detail in 

 particular the method of staining. 



Starting with the sputum, we search for little clumps or rolled- 

 up masses ; if these are not present, the most solid portions of the 

 mucus are brought with forceps upon a clean cover-glass ; very 

 little suffices. With another cover-glass it is pressed and spread 

 out evenly ; drawing one glass over the other, we obtain two 

 specimens, and these put aside or held high over the flame until 

 dry. 



If we desire to examine the specimen quickly, or make a 

 hurried diagnosis, we use the rapid method, with hot solutions ; 



FIG. 54. 



Growth on A gar. 



otherwise we let it stay, in cold solution until the next mornin<* 

 the advantages of which will be later on described. 



TJie Eapid Method. (B. Frankel's method modified by Gab- 

 bet.) The principle is to combine with the contrast stain the 

 decolorizing agent ; but the preparations are not permanent ; 

 the method, however, is very useful. 



Two solutions are required : one of Ziehl's carbol-fuchsin ; 

 the other Gabbet's acid methylin blue. (See No. X., on 

 page 34.) 



The cover-glass containing the dried sputum is passed three 

 times through the flame, as described in the general directions. 

 It is then placed in the carbol-fuchsin solution five minutes (cold), 

 or two minutes in the hot., immediately then transferred to the 



