MR. W. C. D. WHETHAM ON IONIC VELOCITIES. 
345 
The next solutions were chosen to show the motion of the acid radicles, and 
potassium chloride and potassium permanganate were taken. The junction in this 
case, depending on the acid radicles, should, if its motion really shows the course of 
the ions, travel against the current. Such was found to be the case. The solutions 
had a strength of about '046 grm. equivalent per litre. 
Voltmeter at 
grade 23'8. 
Time. 
Position. 
10-8 
4.II 
j-O.S in 10' = -093 in I' 
4.21 
20'35 J 
4.26 
I9'73 I ~ ’1“*^ 4' 
10-8 
4.40 
20’89c/ iiA' 1' 
> 5o in 5 =■ TIO in 1 
4.4.5 
20-34 4 
4.50 
in 5' = -114 in 1' 
A downward current from chloride to permanganate thus gives an upward velocity 
to the junction of O'llO centira. per minute. 
Current reversed. 
Voltmeter at 
grade 23-8. 
Time. 
Position. 
10 8 
4.28 
1 -61 in 5' = -122 in I' 
4.33 
20-33 J 
4..38 
20.011-.58 in .5'=-116 in P 
The downward velocity of the junction is thus 0’1I9 centim. per minute. 
The mean of the two is therefore 0‘1I5 centim. per minute. 
The potential gradient is 3'3G, which makes the velocity for unit gradient 
0*00057 centim. per second. 
As the red permanganate disappears its pdace must be taken by chlorine, and 
hence this ought to give an indication of the velocity of the chlorine ion. For this 
Kohlrausch gives 
0*00053 centim. per second. 
Solutions of one-tenth this strength were then set up (*0046 grm. equivalent per 
litre). 
MDCCCXCIII.—A. 2 Y 
