Discharge of a Large Accumulator. 2G1 



plates of the condenser. Then if i is the current through 

 ABC, and x the charge on the plate nearest to A, 



T di T, . dx x 



dt dt c 



since each of the quantities is equal to the electromotive force 

 between A and C. 

 If t = cos pt, then 



((4 +*v) 



where . _ . L» 1 



A= tan ' ■-.-'- + tan -1 . 



Iv rpc 



Hence 



-dt = \/l ^ S (pt + A). 



Thus the maximum current along AEC is to that along ABC 

 as \' L i p i + R 2 is to \f , 1g 2 +r a ; or if we neglect the resist- 

 ance r of the leading wires, as \f L 2 /) 2 -f R 2 : —^o ; or ne- 

 glecting L, as — . 



Tip- 



In the case of one cell of the battery the polarization- 

 capacity is undoubtedly very large. G. M. Gordon* finds 

 that the polarization-capacity of the surfaces of platinum 

 0*65 cm. 2 , 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 2 , surface separated by about 

 6 mm. The layer of peroxide of lead undoubtedly gives a 

 very large polarization-capacity. The resistance of each cell 

 is about one quarter of an ohm. Even with the small value 

 of R, under the effect of rapidly oscillating currents, such as 

 my experiments show arise when the battery discharges 

 through air or gases, a large portion of the oscillating cur- 

 rents pass through the condenser-circuit. Since the electro- 

 lyte acts as a semi-insulator, with a very high value of p, no 

 current would pass through the condenser-circuit and the 

 electrolyte, and the cells would therefore act like leyden jars. 



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



Phil. Mag. S. 5. Vol. 44. No. 268. Sept. 1897. U 



