438 
DR. HAROLD A. WILSON ON THE 
It seems just possible that this effect is due to salt vapour (or, in the case of air, 
some gas) condensing on the cooler parts of the tube, and to the application of the 
F.D. causing some of this condensed vapour to evaporate, so that until equilibrium is 
again restored the amount of salt passing between the electrodes is abnormally 
large. 
The main object of these further experiments was to test the conclusion that the 
maximum or saturation current carried l)y the vapour is equal to that recpiired to 
electrolyse the same amount of the salt in a solution. 
Using solutions contaiuing 10 grammes in a litre it was not found possible to 
saturate the vapour, except in a few cases when the saturation current was found to 
be approximately that inquired hy the above-mentioned conclusion. 
Experiments were therefore tried with solutions containing 1 gramme in a litre, in 
the hope that witii a smaller quantity of salt it vx)uld be easier to approach the 
saturation current. This device proved entirely successful, and the saturation current 
was in every case nearly inversely })roportional to the electi'O-chemical equivalent of 
tlie salt used. It was also veritied that the saturation current for a particular salt 
was proportional to the concentration of the solution sprayed. 
The following table nives the currents observed at about 1350° C. with 840 volts 
o o 
witli solutions containing 10 grammes in a litre, the outer tube being positively 
charged in every case. 
Salt. 
CsCl . 
Electro-chemical 
equivalent. 
(E.) 
. . 1G8 
Galvanometer 
deflection. 
(C'd 
1=5-2 X 10~'' 
amperes. 
290 
EC. 
4-9 X 10^ 
Remarks. 
Saturated. 
Rbl . 
. . 212 
260 
5-5 „ 
ItUC 03 
. . 115 
316 
3-6 „ 
Not saturated. 
KI . . 
. . 166 
315 
5-2 „ 
Saturated. 
Nal . 
150 
315 
Iff „ 
Nearly saturated. 
Na^COy 
53 
505 
2ff „ 
Not saturated. 
Lil . . 
. . 134 
330 
4-4 „ 
LiBr . 
. . 87 
350 
3-0 „ 
? ? 
With CsCl, Rbl, KI, and Nal, which were all saturated, or nearly so, the product 
EC has nearly the same value, viz., 5‘1 X 10b 
The following table gives the results obtained with solutions containing 1 gramme 
in a litre. 
