70 



Measure the tubercle bacteria in one of the preparations 

 and make a drawing showing a few of them magnified looo 

 diameters. 



§ 1 15. Making cover-glass preparations from sputum. 

 Select the little yellowish colored masses, if present, remove 

 them by means of the fine forceps or platinum loop, and 

 spread them on the cover-glass in a thin layer. If the sputum 

 is homogeneous make the preparations the same as from cul- 

 tures, using a small loopful of the liquid. If the sputum is 

 viscid it is necessary to use the forceps to spread the film on the 

 cover-gla.ss. After drying, the films are fixed by passing 

 the preparations through the flame, after which they are 

 ready to be stained. 



§ 116. Gabbett's method of staining tubercle bac- 

 teria. 



(i) The stain (carbol fuchsin) : 



Fiichsin, i gram. 



Absolute alchool, 10 c. c. 



Sfo carbolic acid 100 c. c. 



(2) The decolorizer and counter stain : 



Methylene-blue powder 2 grams. 



lofc sulphuric acid, 100 c. c. 



Stain the preparation with the first solution as described 

 in (§ 76) then rinse in water and stain one minute with 

 the .second solution which decolorizes and counter .stains at 

 the same time, and again rinse in water. If the film has a 

 bluish tint it is ready for examination, if not, it should be 

 stained a little longer in the second solution. In these prep- 

 arations the tubercle bacteria should appear as slender, more 

 or less curved, rod-shaped bodies of a deep reddish color while 

 the surrounding tissue and other bacteria pre-sent are stained 

 a more or less intense blue. 



