TATE AND FOOTE : ANODE FILMS 



595 



By the ordinary law of shunt resistances, if Ri/R 2 =2.3 

 then R\/R\-\- 2 should equal 3.3, in agreement with the experi- 

 mentally determined value. The ratio of areas of probes 1 and 

 2 was 1:2.28 while the observed ratio of resistances Ri/R 2 was 

 2.3:1. Hence the resistance of the polarization film varies 

 inversely as its area. 



TABLE 1 

 Anode Film Resistance 



Conclusions. Further experimental work has confirmed the 

 existence of an anode polarization film. The resistance of the 

 anode film is less than that of the cathode film, and the two types 

 of polarization resistance appear to be in a ratio of about the 

 same order of magnitude as the ratio of anode to cathode fall 

 of potential. The resistance of the anode film varies inversely 

 with its area, but it should be emphasized that this relation was 

 tested for wires of the same diameter. On account of changes 

 which would be produced in the character of the field it is prob- 

 able that the relation would not hold for wires of different 

 diameters. Skinner has found entirely different values of re- 

 sistance per square centimeter for wires of different diameters. 



