1039 
Wo = resistance of the solution. 
Wz = comparison resistance on the bridge. 
W y= resistance of the “conductivity water”. 
W corrected resistance of the solution in case the water 
possessed an infinitely great resistance. 
If we assume that the conductivity power of the water is inde- 
pendent of the nature of the solution (as will be certainly the case 
with neutral salts) we have: 
1 1 1 1 1 if 
ie We We 
If we call the parts of the bridge wire, when the solution is 
shunted in « and 5 and those when the water only is shunted in 
c and d we have: 
Ee PS read 
W Wo W el 
Wo b 1 a 1 
=- OP —=>-x*= (2) 
Wp a Wo b W 
and 
Ww ad 1 ty 1 
—— = or = ——, 
Wp c Ww a x Wr 
Substitution of (2) and (3) in (1) gives: 
1 EE 4 x6 
== == BEN nr old ee 
Ww Wert d 
If we put 2 the correction to the left, hence the diminution of 
a, Which must be applied in the case when the water had an infi- 
nitely great resistance, we find in a similar manner: 
1 a—x 1 4 
iin ee SNORT er Or ed 
Substitution of (4) in (5) gives: 
at a ¢ a—a  ad—be bec 
bte db d me btw DRR: en a d(a+-b)—be 
if L=a+b=c-+d= length of the bridge wire and if we 
neglect be in regard to dL we have: EK KEE 
If, herein we again neglect Le in regard to £* we get: 
Re 
z=ex (5) . 
Consequently the further the sliding contact is situated towards 
the right, the smaller will be the corrections to be applied. In my 
measurements MW, was always chosen in such a manner that 5 
was as small as possible without the telephone minima becoming 
less sharp. Not a single other observer appears to have applied this 
