EFFECT OF EXTERNAL CONDITIONS ON BACTERIA l6l 



below 37 C. The effect is due to the formation of germicidal 

 electrolytic products in the culture. Anthrax spores are killed 

 in two hours. Subtilis spores were still alive after the current 

 was passed for three hours. 



" 4. A continuous current passed through bouillon cultures 

 of bacteria produces a strongly acid reaction at the positive 

 pole, due to the liberation of chlorin, which combines with oxy- 

 gen to form hypochlorous acid. The strongly alkaline reaction 

 of the bouillon culture at the negative pole is due to the for- 

 mation of sodium hydroxid and the liberation of hydrogen in 

 gas bubbles. With a current of 100 milliamperes for two 

 hours, it required 8.82 milligrams of EkSOi to neutralize i c.c. 

 of the culture fluid at the negative pole, and all the most resist- 

 ant forms of bacteria were destroyed at the positive pole, 

 including anthrax and subtilis spores. At the negative pole 

 anthrax spores were killed also, but subtilis spores remained 

 alive for four hours. 



" 5. The continuous current alone, by means of Du Bois- 

 Reymond's method of nonpolarizing electrodes, and exclusion 

 of chemic effects by ions in Kruger's sense, is neither bacteri- 

 cidal nor antiseptic. The apparent antiseptic effect on suspen- 

 sion of bacteria is due to electric osmose. The continuous 

 electric current has no bactericidal nor antiseptic properties, 

 but can destroy bacteria only by its physical effects (heat) 

 or chemic effects (the production of bactericidal substances 

 of electrolysis). 



" 6. A magnetic field, either within a helix of wire or between 



