l6o GENERAL PHYSIOLOGY 



feet is. Aside from the scientific aspect, it has been thought 

 that much practical good might come from the use of electric- 

 ity as a germicidal agent, but so far the experiments have 

 been disappointing. There is no doubt but that strong cur- 

 rents of electricity would affect bacteria much in the same way 

 that it does other forms of life, but it is very difficult to apply 

 it. If, for instance, a direct current is run through a culture 

 medium, the electrolytic effect on the medium is very marked, 

 and the resulting action on the bacteria is due to the chemicals 

 formed and not to the current itself. An interesting contri- 

 bution to this subject was made by Zeit in 1901, and his 

 conclusions are as follows: 



" i. A continuous current of 260 to 320 milliamperes 

 passed through bouillon cultures kills bacteria of low thermal 

 death points in ten minutes by the production of heat 98.5 C. 

 The antiseptics produced by electrolysis during this time 

 are not sufficient to prevent the growth of even non-spore- 

 bearing bacteria. The effect is a purely physical one. 



" 2. A continuous current of forty-eight milliamperes 

 passed through bouillon cultures for from two to three hours 

 does not kill even non-resistant forms of bacteria. The 

 temperature produced by such a current does not rise above 

 37 C., and the electrolytic products are antiseptic but not 

 germicidal. 



" 3. A continuous current of 100 milliamperes passed 

 through bouillon cultures for 75 minutes kills all non-resistant 

 forms of bacteria, even if the temperature is artificially kept 



