LIQUID MEDIA. 



effect of electricity we may prepare a drop -culture 

 in the moist-chamber (Fig. 42). The cover-glass 

 to be used is provided with two strips of tinfoil, 



FIG. 41. STRICKER'S COMBINED GAS CHAMBER AND WARM STAGE. 



which are isolated from the brass of the microscope, 

 and so arranged that a current of electricity may 

 be passed through them (Fig. 43). 



FIG. 42. SIMPLE MOIST-CHAMBER ADAPTED FOR TRANSMISSION 

 OF ELECTRICITY. 



A much simpler plan, which may also be employed, 

 is to take an ordinary glass slide and coat the sur- 

 face with gold size. The slide is then pressed 



