MORPHOLOGY OF LEUCOCYTES AND RED CORPUSCLES 257 



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-fing'er being 

 placed above the strip, and the edges held between the thumb 

 and index-finger and the index and middle fingers respec- 

 tively ; 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) is now dipped into the drop of blood, and a small quan- 

 tity 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 J 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 



FIG. 54. METHOD OF SPREADING FILMS WITH CIGARET E PAPER. 



is spread out into a long uniform film. In this way a film 

 J inch wide and 2 inches long can be made on a single slide. 

 A fresh piece of paper is to be used for each specimen (see 



Fig. 54). 



The author is of opinion that it is best to adopt the cover- 

 glass method, as he has found that it presents fewer difficulties 

 for beginners; this is not the universal experience, and it is a 

 good plan to try both, and adopt that with which yon get the 

 best results. 



Films are sometimes spread on one slide by means of an- 

 other, which is used as a spreader in much the same way as 

 the cigarette-paper described above. This is very good for 

 malaria parasites, and for alterations in the red corpuscles, 

 but is useless for making differential counts, as some of the 

 leucocytes are carried along with the spreader and left at the 

 end of the film. 



17 



