CHAPTER VIII. 
THE EFFECT OF LIGHT, ELECTRICITY, PRESSURE, 
AGITATION, DRYING, AND ASSOCIATION WITH OTHER 
MICRO-ORGANISMS UPON BACTERIA. 
Very little is known about the influence of electricity 
on bacteria. The majority of the observations hereto- 
fore made on this subject would seem to indicate that 
there is no direct action of the galvanic current on 
bacteria; but the effect of heat and the electrolytic in- 
fluence on the culture liquid may produce changes which 
finally sterilize it. Gottstein and Spilker have recently 
made experiments with an induction current from a 
dynamo machine. They passed the current through 
a spiral wire, which was wrapped around a test-tube 
of glass containing the micro-organisms to be tested, 
suspended in water. The bacillus prodigiosus, sus- 
pended in sterilized distilled water and contained in 
test-tubes having a capacity of 250 c.c., was subjected 
to a current of 2.5 ampéres + 1.25 volts for twenty- 
four hours. The temperature did not go above 30° C. 
No growth occurred when the organism tested was sub- 
sequently planted in nutrient gelatin. It was found that 
stronger currents were effective in a shorter time, but 
in no case was sterilization effected in less than an hour. 
These experiments, however, have not been confirmed. 
Meltzer has shown that while slight agitation of 
cultures of bacteria acts favorably on their develop- 
