82 LABORATORY BACTERIOLOGY 



In making these preparations from blood, hold a cover glass 

 by the edge with a pair of dissecting forceps. With the plati- 

 num loop place a drop of blood on the cover glass near the 

 forceps. Take a thick, square cover glass by the edge, rest it 

 on the first above the drop of blood, hold it at an angle of 

 about 20° from it, and draw it down over the first, thus spread- 

 ing the blood in a very thin, even film over the surface. If 

 the film is thick, the preparation should be rejected and 

 another made. 



