42 CLINICAL BACTERIOLOGY AND H^MATOLOGY 



4. Take the cork between the finger and thumb of the right 

 hand and pass the swab into the patient's mouth, taking great 

 care not to touch his lips, tongue, or palate. Press it firmly 

 against the area which you wish to examine, and rotate it 

 between the finger and thumb so as to remove some of the 

 secretion, and, if possible, some of the membrane. With- 

 draw the swab, again taking* care not to touch any part of the 

 mouth, and replace it in the tube. 



5. Withdraw the tongue depressor, and place it in the anti- 

 septic lotion or boiling water. 



6. Push the cork home into the tube. 



Method of examining the Swab. This may be carried out 

 by means of stained films, prepared directly from the swabs, 

 or by means of cultures. The former method is less useful 

 than the latter, but we shall consider it first, as it can be per- 

 formed by anyone who possesses a microscope carrying a 

 iVinch oil-immersion lens, and often gives valuable informa- 

 tion. Moreover, it does not take long, and but little delay is 

 caused. 



Requisites. i. Clean slides and cover-glasses. 



2. Stains LofBer's blue or carbol thionin, and aniline gen- 

 tian violet. 



3. Grain's iodine solution and alcohol methylated spirit 

 will do. 



4. Strips of white filter or blotting paper. 



5. Balsam. 



Method. Prepare a film in the following way : Rub the 

 swab on the middle of a clean slide, so as to spread some of the 

 secretion into a thin layer on the surface. Allow it to dry, 

 and fix it by passing it slowly through the flame, until the 

 upper surface is just too hot for you to press your finger upon 

 it in comfort. Allow it to cool. 



Now filter a few drops of LofBer's blue or carbol thionin on 

 to. the film, and allow it to act for two minutes. Wash under 

 the tap. 



Dry by pressing carefully with strips of blotting-paper, and 

 then over the flame. Place a drop of balsam upon the film, 

 and apply a cover-glass. 



Prepare a second film, and stain by Gram's method (p. 24), 

 counterstaining by dilute carbol fuchsin. 



The films are now examined microscopically (see p. 27). We 



