TROWBRIDGE. — ELECTRICAL DISCHARGES. 437 



In the case of one cell of the battery the polarization capacity is un- 

 doubtedly very large. C. M. Gordon * finds that the polarization capacity 

 of two surfaces of platinum 0.65 cm." separated by an interval of 2 mm. 

 amounts to more than 50 microfarads. The cells of my battery consist 

 of lead plates of about 10 cm.^ surface separated by about 6 mm. Tlie 

 layer of peroxide of lead undoubtedly gives a large polarization capacity. 

 The resistance of each cell is about one quarter of an ohm. Even wi'h 

 this small value of R, oscillating currents such as my experiments show 

 arise when the battery discharges through air or gases. A large portion 

 of the oscillating currents pass through the condenser circuit, and the 

 electrolyte acts as a semi-insulator. With a very high value of p, no 

 current would pass through the electrolyte, and the cells would therefore 

 act like Leyden jars. In the case I am considering, the Plante cells evi- 

 dently act like leaky Leyden jars coupled in series. If C is the appar- 



C 

 ent capacity of one cell, — would be the capacity of n cells. 



n 



An examination of the photographs of the oscillations produced by 

 2,500 cells, showed an apparent capacity of about 1,000 electrostatic units. 

 Five thousand cells gave an apparent capacity of about 500 electi'ostatic 

 units, as should be the case. The small apparent capacity C results 

 from the leaking of the condenser due to the conduction through the 

 electrolyte. 



Since the discharge from an accumulator of a large number of cells is, 

 in general, oscillatory, I am led to the belief that the discharge from any 

 primary battery is also oscillatory, for in all cases we have to deal with 

 capacity and self-induction. It is evident that a galvanometer in circuit 

 with a Geisler tube or a telephone cannot detect the oscillatory dis- 

 charge, since it is of high period. Moreover, when a Geisler tube is 

 lighted by a large battery with no resistance save that of the Geisler 

 tube and the battery in the circuit, arid the light is examined in a revolv- 

 ing mirror by the eye, no oscillations or intermittence of light can be 

 perceived on account of the flaming discharge through the rarefied gas. 



The oscillatory discharge may be said to be the common occurrence of 

 nature in the case of electrical discharges, and the one direction discharge 

 the uncommon. This has been expressed l)y tlie remark that electricity 

 takes the path of least resistance ; this common belief, however, must be 

 modified under certain conditions of resonance. In general, nature avoids 

 a unidirectional discharge. 



* Wied. Ann., No. 5, 1897, p. 28. 



