ELECTRICAL WAVES AND SOME OF ITS APPLICATION'S. 
23 
Even if L = ~ the correction would only be 1 per cent. The resistance R of the zinc 
sulphate solution was determined for steady currents, and it can be shown that the 
change of resistance due to the concentration of the currents on the surface is quite 
inappreciable for the periods investigated on account of the high specific resistance of 
the solution. 
This can experimentally be shown as follows ; a tube containing the solution to be 
tested is placed inside a solenoid of a few turns, and a detector needle placed in the 
solution. After the passage of a discharge it will be found that the effect on the 
needle is the same as when the solution is removed, showing that there is no screen¬ 
ing action on the needle due to the solution. Since the law of decrease of magnetic 
force from the surface inwards is the same as for the decrease of amplitude of a 
current through the conductor, it follows that the amplitude of the current at the 
centre of the solution was the same as at the surface, and that there was no alteration 
of the resistance of the electrolyte due to concentration of the current on the surface. 
An air condenser of calculable capacity C was discharged through a circuit whose 
inductance L for rapid frequencies could be very approximately determined. 
The value of jo = from theory was found to agree to within 3 per 
cent, of the experimentally-determined value, and, from the difficulty of accurately 
calculating the inductance, it is probable that the experimental determination is nearer 
the true value. 
From the close agreement of theory and experiment, we have indirectly proved 
that the resistance of an electrolyte like zinc sulphate is the same for high frequencies 
as for low. 
As an example of the determination of the period of oscillation, the value of N, the 
standard inductance, was 6500 units. When the current was the same in both 
circuits, the value of E, was 168 ohms. 
Therefore 
P = 
R 
N 
6500 
= 2-6 lOh 
The frequency n = pl2Tr = 4’1 10''. 
The value of the capacity and the inductance for rapid frequencies of the discharge 
circuit could also be determined. 
If a Leyden jar of unknown capacity C be replaced by an air condenser of known 
capacity C', the value of L remaining unaltered, and the value of the resistance 
necessEiry for ec^uality of currents in the two circuits determined as before, then if p' 
and It' be the new values of pt and R, 
1 1 
= 71.6 r = ’ 
R = and R' = p'N. 
