DIPHTHERIA. 47 



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. Withdraw 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 

 antiseptic 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 cul- 

 tures. The former method is less useful that the latter, 

 but we shall consider it first, as it can be performed by 

 anyone who possesses a microscope carrying a T ^ in. 

 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 Loffler's blue or carbol-thionin, and aniline 

 gentian violet. 



3. Gram'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 to 

 prevent your pressing your finger upon it in comfort. 

 Allow it to cool. 



Now filter a few drops of Loffler's blue or carbol- 



