514 MR. W. C. D. WHETHAM ON THE VELOCITIES OF THE IONS. 
Velocity = -46, “48, °48, -48, -46, 49, 50, -49, 48. Mean = 0°480 centim. in 
10 mins. 
Mean galvanometer reading = 31:0. Therefore y = 1°08/164. 
Temperature of water-bath, 17°°4. Area of cross-section of tube = 0°442 square 
centim. 
Therefore 
v, = 0°000481 centim. per sec. 
Thus the specitic velocity of the silver ion, moving through a decinormal solution 
of silver nitrate in agar jelly at 18°, is 
Vag = 0°000488 centim. per sec. 
For the corresponding solution in water, KOHLRAUSCH gives 
Vag = 0:000462 centim. per sec. 
The temperature coefficient was determined by cooling the water-bath to 8°-2. 
Mean conductivity at 8°°2 = 7°12 x 107% 
Velocity = °37, °37, °39, -40, 40, -40, -41, 43, -40. Mean = 0°397 centim. in 
10 mins. 
The electromotive force applied being the same as before, we can compare this with 
0:480 centim. in 10 mins., the velocity at 17°°4. The temperature coefficient at the 
mean temperature of 12°°8 is thus 2°05 per cent. per degree. 
The Sulphate Growp.—As an example of an anion the velocity of the SO, group 
was determined by the use of decinormal jelly solutions of sodium sulphate and 
sodium chloride, barium chloride being added to the latter as indicator. 
The galvanometer was re-graduated, the following readings being enough for our 
purpose. To the resistances 10 ohms must be added for the galvanometer. 
70 ohms 50°8, 230 ohms 23°'8, 
LO ea, 2 DIE 
Resistance of sodium chloride solution in cell at 14°°6 = 151°5. 
53 5 sulphate __,, i 14 65— lion. 
Therefore mean conductivity at 15°°2 = 9°69 x 107%. 
Velocity = -24, -24, -26, -26, 26, -27, 27, 27, 25, ‘24, °25, -27, -27, -26, -24, 
"25, ‘27, °26. Mean = 0°257 centim. in 10 mins. 
Mean galvanometer reading = 23°3. Therefore y = 1°08/246. 
Temperature 15°-2. Area of cross-section of tube = 0°430 square centim. 
Therefore 
Vv, = 0:000406 centim. per sec. 
