To Make a Wet Film 



The same procedure is gone through as in the 

 case of a dry fihn. It is well to polish the slide 

 and coverglass immediately before use with a clean 

 handkerchief. When the exuding drop of blood 

 reaches the size of a small pin's head, a coverglass 

 is picked upi rapidly with forceps, or the edges are 

 grasped between finger and thumb, and allowed 

 to touch the diop without ' dabbing ' the skin, and 

 again rapidly placed drop downwards upon a 

 slide. A gentle tap or two with a needle or 

 forceps may aid in the film formation, but the 

 pressure must not be great or the corpuscles will 

 be found laked and invisible. 



The requirements of a suitable wet 'film are : — 

 There should be a central transparent area shew- 

 ing no sign of a granular appearance, and even 

 looking quite free from blood. If this appearance 

 is present, the film is probably a good one. If the 

 centre of the film appears reddish or granular, it 

 is useless to examine it (for young parasites), as 

 the corpuscles will be massed together and the 

 parasite not seen. Under the microscope a good 

 film should shew clear, even, circular discs, lying 

 side by side and not overlapping each other. It 

 may be necessary to make several before a suffi- 

 ciently good one is obtained. 



To Label Films 



Films should always be labelled as soon as 

 possible, otherwise uncertainty and annoyance are 

 sure to arise. The use of paper labels is not at all 

 necessary in routine work. 



