16 LABORATORY GUIDE IN BACTERIOLOGY 



as the depth of the funnel to be used (Fig. 8, a), and fold 

 to half the size (Fig. 8, b) so as to make i cover 2, and 3 

 cover 4 



2. Fold this to make i cover 2 and 3 cover 4 (result: 

 Fig. 8, c). It consists of four layers and forms a square. 



3. Fold the upper part, consisting of two layers, 



a- 



FIG. 8 



Method of Folding Paper Filter 

 (For reference letters see text) 



from i to 2 (Fig. 8, d). The shaded triangle, 2-3-4, 

 now has six layers; the other 1-3-4, two layers. 



4. Fold the upper double layer so as to make 2 cover 

 a point in the diagonal at 5, taking care to make a sharp 



