ACTION OF ELECTEICITY 27 



been kept in the form of a desiccated powder for five months, 

 but at a later date the virulence was lost. 



(5) Action of Electricity. — Many workers have made ex- 

 periments to determine the action of electrical currents on 

 various bacteria, but the results hitherto obtained are very 

 indefinite and discordant. It is possible, however, that in 

 the future this agent, the application of which increases 

 daily, may play an important part in the destruction of 

 bacteria. 



(6) Action of Chemical Agents. — Chemical agents are de- 

 structive to bacteria by virtue of their poisonous action on 

 protoplasm. The haloid elements, mineral acids, alkalies, 

 metallic salts, and various organic compounds, all exert a 

 strong germicidal or retarding action on the growth and 

 development of micro-organisms. 



