L 9 
quickly carried to the right along the whole length of 
the slide (Fig. 5). Immediately the film is made it 
should be waved to and fro until it is seen to be quite 
dry. The quicker the film dries the more perfectly 
preserved will be the red cells of the blood. 
The Characters of a Good Film 
1. As a film is needed for the detection of 
minute forms of the parasite within the red cell, the 
film must be uniform and as thin as possible. 
2. Films should be made so that, if desired, the 
leucocytes may be differentially counted. A little 
practice will enable one to make films with the upper 
and lower edges more or less parallel with the edges of 
the slide, and terminating in a pointed manner about 
half an inch from the right hand end of the slide. 
3. In the case of very anaemic bloods, e.g ., those 
of i malarial cachexia, 5 difficulty will arise from the film 
being too thin. The needle in this case must be 
carried very loosely and rapidly along the slide and a 
thicker film thus made. When blood with difficulty 
adheres to the slide, good evidence of extreme anaemia 
is obtained. 
