FIXATION OF BLOOD FILMS. 163 
longitudinally. Paper which is decidedly ridged or 
ribbed will not answer. 
3. Needle. 
Method.—The patient is pricked and the first drop of 
blood wiped away as before. One of the half strips of 
cigarette paper is now held in the right hand, the index 
finger being placed above the strip and the edges held 
between the thumb and index finger and the index and 
middle fingers respectively; this converts it into a 
gutter, the convex edge of which is downward. The 
edge of this gutter which points away from you (and 
which is formed by a machine-cut edge of the paper) 
Fic. 28.—Method of spreading films with cigarette paper. 
is now dipped into the drop of blood and a small 
quantity picked up on its lower surface. This lower 
surface is then placed on a clean slide parallel to one 
of its shorter edges and about half an inch from it, 
and pressed gently upon it so as to flatten out the 
paper gutter; as this flattens out the edge of the drop 
of blood on its under surface will follow it. The strip 
of paper is now drawn towards the other end of the 
slide with a steady uniform movement, and in doing 
so the drop of blood is spread out into a long uniform 
film. In this way a film } in. wide and 2 in. long can 
be made on a single slide. ‘A fresh piece of paper is to 
be used for each specimen. 
M2 
