204 



THE AMEEICAN MONTHLY [September, 



Electro-Microscopic Slide for Testing the Antiseptic Power of 



Electricity. 



By ROBERT L. WATKINS, M. D., 



NEW YORK, N. Y. 



The accompanying cut represents an instrument that I have devised 

 for the purpose of ascertaining w^hether or not electricity will destroy 

 the life of germs. It is the result of a number of experiments to con- 

 firm the belief, I have long held, that electricity is an antiseptic and dis- 

 infectant. I also learned while experimenting that Apostrali had made 

 the same claim. 



The instrument consists of a glass slide in the centre of which is a 

 sunk cell. Two grooves, each |-inch long, run from this cell outward. 

 Two brass pieces are fitted over the extremities of the slide in such a 

 manner that the rounded points, the under surfaces of which are lined 

 with platinum, will cover a portion of the grooves. These rounded 

 points do not touch the glass, but are raised above the grooves about 

 ^ of an inch. Binding posts are riveted to the brass for connection 

 with a battery. 



SLIDE FOR TESTING THE ANTISEPTIC POWER OF ELECTRICITY. 



In order to apply this instrument, a sufiicient quantity of the fluid 

 containing the bacteria should be used to fill the cell and grooves. A 

 cover glass is placed over the cell and its contents. Two small clean 

 sponges, saturated with either the fluid or distilled water, are then 

 placed underneath the platinum points and in contact with the fluid in 

 the grooves. The bacteria are now ready for observation, the electricity 

 is turned on and the quantity noted by the milli-ampere meter to stop 

 all signs of germ life. They can now be cultivated on gelatine in the 

 ordinary way should it be desired to determine whether or not their 

 vitality has been entirely destroyed. 



Other uses for this slide will readily occur to one working in this 

 field ; for example, the effect of electricity on the blood and difterent 

 tissues. 



I have found this instrument very satisfactory, not only as an easy 

 but as a quick way of finding out the amount of electricity required to 

 destroy micro-organisms. 



