I O6 BACTERIOLOGY. 



firmly down on gold leaf or tin-foil and allowed to 

 dry. When dry, the metal is scraped away, leaving 



FIG. 43. APPARATUS ARRANGED TOR TRANSMITTING ELECTRICITY. 



two triangles with a small interval between them, as 

 in Fig. 44. 



FIG. 44. SLIDE WITH GOLD-LEAF ELECTRODES. 



The liquid containing the micro-organisms is 

 placed between the electrodes, covered with a cover- 

 glass, and then subjected to the electric current. 



