1888 .] Mr W. Peddie on Effects of Electromotive Force. 413 
Another series of experiments gave the numbers 
12-2 
12-67 
11-7 
12-0 
12-9 
1-248 
0-86 
0-65 
0-58 
0-46 
36-6 
45-10 
47-3 
48 
65 
Hence it is evident that the apparent resistance diminishes greatly 
as the current density increases, the electromotive force being kepd 
practically constant. 
Next the current density was kept constant while the electro- 
motive force was varied. The current density being constant, it 
follows that any variation of the opposition in the electrolytic part 
of the circuit is proportional to the variation of the electromotive 
force acting between the electrodes. The first row underneath gives 
the number of Bunsen cells used in the circuit, and the second row 
gives the difference of potential of the electrodes, the electromotive 
force of a Latimer-Clark cell being taken as unity — 
1 2 3 4 5 6 7 
1-46 1-5 1-36 1-34 1-30 1-34 1*34 
The result of another series of experiments is as follows : — 
6 5 4 3 2 
2-57 2-52 2-5 2‘5 2*5 
In both series the first few numbers of the second row are higher 
than the rest ; but in the former series the number of cells was being 
increased from the commencement, while in the latter it was being 
diminished. Hence the cause of this seems to be instrumental. 
The suspending fibres of the needle of the electrometer retained 
their state of torsion to an appreciable extent, and this would tend 
to produce the effect noticed. 
Thus the numbers in the second rows above are practically con- 
stant, and we may conclude that, so far as the electrometer method 
used can indicate, no variation of the total apparent resistance is 
produced when the electromotive force in the circuit is altered, the 
current density being kept constant. 
It follows that the quantity p + — is constant, so that either p 
and e are both constant, or p varies equally and oppositely to — . 
Hence a conducting circuit containing an electrolytic arrangement 
