KILLED, STAINED 8 1 



3. Dip the cover-glass into a beaker containing hot 

 water in order to remove some of the vaseline adhering 

 to it. 



4. Wash successively in alcohol, xylol, ether, and 

 alcohol, to remove the last traces of grease. 



5. Wash in water. 



6. Stain, wash, dry, and mount as for an ordinary 

 cover-slip film preparation (vide pages 83-85). 



2. Killed, Stained. In this method three distinct 

 processes are necessary: 



"Preparing" and "fixing" the film. 



Staining. 



Mounting. 



Preparing the Film. 



1. Flame a cover- slip and place is on a piece of filter 

 paper. 



2. Place a drop of water on the centre of the cover- 

 slip by means of platinum loop. 



3. Obtain a small quantity of the material to be 

 examined upon a sterilised platinum loop (see pages 

 74-76, steps 2 to n) and mix it with the drops of water 

 on the cover-slip. 



4. Spread the drop of emulsion evenly over the 

 cover-slip in the form of a square film to within i mm. 

 of each edge of the cover-slip. 



5. Allow it to dry completely in the air. 



Fixing. Fix by passing the cover-slip, held in the 

 fingers, three or four times through the flame of a Bun- 

 sen burner. 



In some instances (e. g., when the films after staining 

 are intended for micrometric observations) it is almost 

 essential to fix by exposure to a uniform temperature . 

 of 115 C., for twenty minutes. This is best done in a 

 carefully regulated hot-air oven. 



Fixation may also be effected by immersing in some 

 fixative fluid, such as one of the following : 

 6 



