OF FLAMES CONTAINING SALT VAPOURS. 
503 
circular patch at the centre of the grating on each electrode was heated by the flame. 
The lower electrode was nearly white hot usually, and the upper red hot, more or less, 
according to its position. 
Diagram No. 1 shows the relation between the current and E.M.F. when a 
normal solution of potassium carbonate was sprayed for fonr positions of the upper 
electrode, which was charged positively, the lower electrode being in the same position 
in each case, viz., 5‘6 centims. above the flame tube. 
Diagram No. 1. 
It will be observed that as the distance between the electrodes is increased, the 
E.M.F. necessary to produce approximate saturation increases very rapidly, but the 
saturation value of the current, where it is actually reached, is independent of the 
position of the upper or positive electrode. Diagram No. 2 shows the relation 
between the current with 200 cells and the distance between the electrodes, the lower 
electrode being kept fixed and negatively charged as before. 
0 123456789 cms. 
The falling ofl in the current as the upper electrode is raised is very rapid at from 
3 to 6 centims. distance. Up to 3 centims. distance the temperature of the upper 
electrode remained sensibly constant, bnt above this distance it became cooler as the 
electrode was raised higher in the flame, and at 6 centims. distance it was only red 
