314 



The Electrical Reactions of certain Bacteria, and an Application 

 in the Detection of Tubercle Bacilli in Urine by means of 

 an Electric Current. 



By Charles Euss, M.B. 



(Communicated by A. D. Waller, M.D., F.R.S. Received May 21, — Read 



June 24, 1909.) 



Introduction. 



The aim of the following experiments was to ascertain whether bacteria 

 suspended in an electrolyte through which a current passes are transmitted 

 to either electrode, and if so, whether pathogenic organisms could be collected 

 and extracted by such means from pathological liquids. 



Method of Experiment. 



The first observations as to a possible migration of bacteria under the action 

 of an electric current were made in the following way : — 



A cover square was fitted with two platinum foil terminals, separated 

 about 6 mm. from each other. A drop of weak bacterial emulsion 

 made electrical connection between these two terminals, and was prevented 

 from evaporating by another cover square resting on the top of the first one, 

 the edges of which were greased ; the " glass cell," as it may be called, was 

 then mounted on a stand (fig. 1), which rested on the stage of a microscope, 

 and a current of about 1 milliampere sent through it. 



Fig. 1. 



It was at once found that the bacteria, viz., Staphylococcus aureus, 

 Streptococci, M. melitensis, B. tuberculosis, B. coli, B. typhosus, B. of Gaertncr, 

 B. pyocyaneus, and Hoffmann's bacillus, moved towards one electrode, their 

 direction of movement being reversed on reversal of the current ; the 

 velocity of transmission was approximately estimated at about 1/100 mm. 

 per minute (under the particular conditions of pressure and sectional area). 



