3O MANUAL OF BACTERIOLOGY. 



objective, an ordinary " high power " | to ^ inch dry objec- 

 tive, and a high power ^ inch oil-immersion objective are 

 needed. The magnification with the f or J inch objective 



FIG. 



Microscope. 



is about 75 to 100 diameters; with the ] to ,1 inch 300 to 

 500 diameters; with the ^ immersion 750 to 1,000 diame- 

 ters. The magnification varies according to the eye-piece 

 used, as well as with the objective. A i inch and 1.1 inch 



