xiv STAINING OF TUBERCULOUS SPUTUM 61 



cover-glass in a pair of forceps, pass it successively from 

 one pot to another, a procedure which saves both time and 

 material. For the solutions are always ready for use and 

 may be employed over and over again. 



Repeat the process, using carbol gentian-violet instead 

 of carbol fuchsine, and vesuvine or Bismarck-brown instead 

 of methylene-blue. 



Carbol gentian-violet : 



5 per cent carbolic acid . .10 vols. 



Concentrated alcoholic solution of 



gentian-violet ... 1 vol. 



Leave the specimen in this stain, which must be warmed 

 of course, for at least five minutes. 



Be careful not to leave the film in the hydrochloric 

 acid too long. 



Vesuvine should be used in concentrated aqueous 

 solution. 



The tubercle bacilli are stained blue on a brown ground. 



(2) Sputum kept in carbolic acid. \ 



(a) Pour 100 cc. of 5 per cent carbolic acid into a small 

 flask. 



(b) Add 10 to 20 cc. of the sputum, unless the latter is 



watery (vide infra). 



(c) Shake vigorously ^or five minutes, till the sputum is 

 thoroughly disintegrated. 



(d) Pour the contents of the flask into a conical urine- 

 glass and allow it to stand for twelve to twenty-four hours. 



(e) Decant the supernatant fluid. 



