OF FLA^IES CONTAINING SALT VAPOURS. 
507 
point on the batteiy nsed to charge the electrodes and adjusting tlie position of the 
wire until no current passed through the galvanometer. The wire and connections 
with the electrometer are shown in fig. 2. 
The wire took up the potential of the flame very quickly, so that even if it was 
connected to earth through a high resistance its potential was not affected 
appreciably. The wire was always kept as nearly as possible so as to pass through 
the axis of the flame ; if this was not done the potential curves obtained were 
considerably altered, although their general character remained the same. 
Diagram No. 7 shows some of the results obtained when the electrodes were 
3'8 centims. apart, the upper electrode being positively charged and the salt solution 
sprayed a ^ normal rul)idium chloride solution. 
Diagram No. 7. 
C' 
5 
Cj 
o 
In this case, in which both of the electrodes were bright red hot, the fall of 
potential between the electrodes is very similar to that observed in gases at low 
pressures. Near each electrode there is a rapid fall of potential and in the interven¬ 
ing space an approximately uniform small potential gradient. This potential gradient 
is approximately proportional to the potential difference between the electrodes. The 
variation of the drop of potential at the negative electrode with the potential 
difference between the electrodes can be rej^resented by the formula 
0-873E — 4-4, 
3 T 2 
