1906.] 



Action on Bacteria of Electrical Discharges. 



65 



Series 1, on Table I, this bacillus survived exposure to the discharge for 

 15 minutes, with a development of acidity in the emulsion equivalent to 

 019 per cent, of nitric acid, whilst in the experiment of Series 2 of the 

 same table the bacillus was destroyed after exposure to the discharge for 

 only 10 minutes, with resulting acidity of the emulsion equivalent to 0"14 per 

 cent, of nitric acid. But an occasional inconsistency of results is only what 

 may be expected in experiments of this kind, in which the primary factor is 

 a form of electrical force which canuot be regulated with accuracy, and does 

 not affect the main points at issue. 



Table I. 



Species. 



Duration 

 of 



exposure , 



to the 

 discharge. 



Current at 

 100 volts 

 supplied to 

 the motor 



driving 

 alternator. 



Acidity (calcu- 

 lated as nitric 

 acid per c.c.) 

 of bacterial 

 emulsion at 



end of 

 experiment. 



Percentage 

 of acid in 

 emulsion 

 after 

 experiment 

 (calculated as 

 nitric acid). 



Result of experi- 

 ment. 



Distance of Platinum Brush above Surface of Fluid, 2 "5 cm. 



Series 1. 















mins. 



amperes. 



gramme. 









15 



7 



0-0019 



0-19 



Some growth, but 













marked inhibition 





15 



7 



0-0024 



0-24 







B. dysenteries ... 



15 



7 



-0023 



0-23 







B. coli communis 



15 



7 



-0021 



0-21 







B. pyoeyaneus ... 



15 



7 



0-0023 



0-23 









15 



7 



0-002 



0-2 







Series 2. 















10 



6-75 



0-0014 



0*14 









10 



6-75 



-0013 



0-13 







B. dysenteries ... 



10 



6-75 



0-0014 



0-14 







B. coli communis 



10 



6-75 



0-0016 



0-16 







B. pyoeyaneus ... 



10 



6-75 



0-0014 



0-14 









10 



6-75 



0-0014 



0-14 







Series 3. 















10 



6 



0-0008 



0-08 



+ 





10 



6 



o-oon 



0-11 



- 



B. dysenteries ... 



10 



6 



0-0008 



-08 







B. coli communis 



10 



6 



0-0012 



0-12 







B. pyoeyaneus ... 



7-5 



9 



0-0009 



0-09 









15 



9 



0-0025 



0-25 







Series 4. 















7 



5 











j B. coli communis 



7 



5 











B. pyoeyaneus ... 



7 



5 











\ B. megaterium ... 



7 



5 







Some growth, but 



1 











marked inhibition 



j B. prodigiosv.s . . . 



7 



5 











VOL. Lxxvni. — B. 



