262 Prof. J. J. Thomson on the Theory of Conduction of 



compared with k 1} the velocity of the positive, the value of 

 X at the negative plate is large compared with its value at the 

 positive. 



The curve representing the electric intensity between the 

 plates is shown in jSg. 2. In this case & 2 /^i is a large 

 quantity. 



Fig. 2. 



The fall of potential across the layer whose thickness is X x 

 is equal to 



and this is equal to 



1 !Ldx. 



Jo 



IXqXj 



where 



and 



^X 1 X 1 +i^log(v/ / 3+ V1 + /3): 



Hence, if fi is large, the fall of potential across the layer 

 whose thickness is \j next the positive plate, is approximately 



Similarly, if 





and if /Si is large the fall of potential across the layer whose 

 thickness is X 2 is approximately 



