122 Proceedings of Boyal Society of Edinhurgh. [jan. 16 , 
the final to the initial resistance, has the value 10. But we have 
just seen from experiment that the true value of that ratio is 2. 
Hence the close correspondence between the curve represented by 
the equation (B), and the observed curve merely shows that the 
other causes of variation in the current strength are of such a 
nature that their effects can be represented as due to variation in 
the value of the transition-resistance, according to the law (A) : so 
that in equation (A), the constant Eq does not give the true final 
value of transition-resistance. 
One cause of variation of the strength of the current of which I 
have taken no account, consists in the decomposition of the liquid 
by smaller electromotive forces than are necessary for visible decom- 
position, the products of decomposition being dissolved in the liquid. 
Also no account has been taken of any variation of capacity 
which may occur. How Varley has shown that the capacity of 
such an arrangement as we are dealing with, increases as the 
electromotive force increases. He used one of the ordinary methods 
of determining the capacity of a condenser. It is easy to show 
the same effect by the methods I have been using. If the circuit 
including an electrolyte and a battery be broken, for a short time, 
during the process of charging the plates, and be again completed, 
the current is found to be stronger. This shows that the capacity 
of the plates has increased in the interval, thus diminishing the 
reverse electromotive force of polarisation. In the following 
experiment readings were taken at intervals of five seconds, and a 
break was occasionally made in the circuit. The interval of break 
was half a minute. 
Experiment \h. 
Deflection. 6'41, 5*31, 4-71, 4*21, 3’81, 4‘11, 3’41, 
3-11, 2-91, 2-71, 2-59, 3T1, 2-71, 2*47, 2*33, 2*24, 
2*15, 2-51, 2-26, 2T2, 2-03, H96, 1*91, 2T6, 
1-91, 1*84, 1-79, 1-75, H86, 1*76, H71, 1*67, 
1-73, 1-66, 1-58, 1-55, 1*52, 1-47, 1*45, H42, H61, 
1-51, 1-46, 1-44, 1-40, 1-54, 1*46, H41, H37, 1-36. 
The same phenomena appear during discharge of the plates, 
the increase of current-strength after the break being due, in this 
case, to the decrease of capacity causing increase of the electro- 
