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ON THE NATURE OF THE ELECTRIC DISCHARGE 

 THE ONE-FLUID AND THE TWO-FLUID 



THEORIES. 1 



Francis E. Nipher. 



_ The dissymmetry in the discharge effects at the posi- 

 tive and negative terminals of an electric machine is now 

 ascribed to the difference in the size of the carriers of the 

 electric discharge. In my former paper in these Trans- 

 actions evidence has been presented, which shows that 

 this dissymmetry is due to the fact that the negative 

 electrons are being forced out under "pressure" at the 

 negative terminal, and that they are being drawn in 

 at the positive terminal under conditions which may 

 be likened to those on the exhaust side of a pump. 

 Characteristic forms of discharge lines usually attrib- 

 uted to positive and negative discharge are shown 

 in Plates XVTII and XIX, Figs. A and B. 



Such plates were obtained by means of the arrange- 

 ment shown in Fig. 1. 



The lines leading from the terminals of an influence 

 machine are separately grounded in the yard outside- 

 of the building. In each line there is a spark-gap of sev- 

 eral centimeters at the machine terminal. Each line has 

 another gap, the two ends of which terminate in pin- 

 heads which make a spring contact with copper plates 

 P and P 1 . The copper plates rest on sheets of glass. 

 The pin-head nearest the machine in the positive line, and 

 the one nearest the ground in the negative line are in 

 Fig. 1 shown as resting on the film of a photographic 

 plate. The other pin-heads rest on the copper sheets. 

 In each case there will be an inflow of Franklin's fluid 

 from the copper plate to the pin-head. This inflow is in 



1 Continued from No. 1, Vol. XIX. Presented before The Academy 

 of Science of St. Louis, May 2nd, 1910. 



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