104 



BACTERIOLOGY. 



the point 7, and the fold 4 is formed, and by carrying 

 1' to 3 the fold 6 is produced; and by bringing 1 to 3 

 and V to 7 the folds 2 and 8 result, 



Thus far the ridges of all folds are on the side of the 

 paper next to the table on which we are folding. The 



paper is now taken up and each space between the seams 

 just produced is to be subdivided by a crease or fold 

 through its centre, as indicated by the dotted lines in 

 Fig. 1 6, but with the creases on the side opposite to that 



FIG. 17. 



occupied by creases 1, 2, 3, 4, etc., first made. As 

 each of these folds is made the paper is gradually brought 

 into a wedge-shaped bundle (Fig. 17, a), which when 

 opened assumes the form of a properly folded filter 

 (seen in 6, Fig. 17). Before placing it upon the fun- 

 nel it is well to go over each crease and see that it is 



