121 
1888 .] Mr W. Peddie on Transition-Resistance. 
Experirrwnit 3a. 
Time in seconds, 5 10 15 20 
Deflection during charge, 9*38 6 ’3 8 5 ’38 4 '68 
These three experiments were performed in the order indicated 
on the same day. The next experiment was made on the following 
day. 
Experiment 4 a. 
Time in seconds. 
10 
15 
20 
25 
Deflection during charge. 
8-6 
6-5 
5-5 
4*8 
Deflection during discharge, 
3-41 
2-81 
2-51 
2*21 
In another experiment care was taken to ensure that the electro- 
motive force of the battery had the same value when the plates 
were to be charged as it had when thrown out of the circuit 
previous to discharge of the plates. The following table gives the 
result : — 
Experiment 5 a. 
Time in seconds, 
5 
10 
15 
20 
25 
Deflection during discharge. 
3-98 
2-98 
2-38 
2-08 
1-93 
Deflection during charge. 
7-35 
5*85 
4-95 
4-45 
4-05 
These experiments show that the magnitude of the transition- 
resistance is about doubled when the plates are polarised fully by a 
Daniell cell. They were all made when the plates had been 
unheated for some weeks. Corresponding experiments were made 
after the plates had been heated, and little difference could be 
detected in the values of the initial deflections during charge and 
discharge. This shows that the difference formerly observed was 
due to the transition-resistance. The only cause of uncertainty 
lies in the fact that, in the time which elapsed between taking out 
the battery and connecting the plates, the electromotive force of 
polarisation might have largely diminished. This interval was 
only a small fraction of a second. But the polarisation does not 
so diminish, for the initial value of the depolarising current was 
found to be the same even if the discharge was commenced one 
minute after breaking the circuit. When the plates were heated 
a resistance of about 600 ohms had to be placed in the circuit to 
reduce the deflections to their value before heating. 
In the formula (B), the constant a, which represents the ratio of 
