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 | 4.11 | 21.42 |   |
.93 in 10′ = .093 in 1′ .62 in 5′ = .124 in 1′ |
| 4.21 | 20.35 | |||
| 4.26 | 19.73 | |||
| 10.8 | 4.40 | 20.89 | |
.55 in 5′ = .110 in 1′ .57 in 5′ = .114 in 1′ |
| 4.45 | 20.34 | |||
| 4.50 | 19.77 | |||
A downward current from chloride to permanganate thus gives an upward velocity to the junction of 0.110 centim. per minute.
Current reversed.
| Voltmeter at grade 23.8. |
Time. | Position. | ||
| 10.8 | 4.28 | 19.72 | |
.61 in 5′ = .122 in 1′ .58 in 5′ = .116 in 1′ |
| 4.33 | 20.33 | |||
| 4.38 | 20.91 | |||
The downward velocity of the junction is thus 0.119 centim. per minute.
The mean of the two is therefore 0.115 centim. per minute.
The potential gradient is 3.36, which makes the velocity for unit gradient
0.00057 centim. per second.
As the red permanganate disappears its place 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).
