MR. W. C. D. WHETHAM ON THE VELOCITIES OF THE IONS. 513 
Resistance of calcium chloride solution in cell at 18° = 180 ohms. 
” sodium Dy 2? oy) = 170 7) 
Mean conductivity = 8°91 x 107%. 
The junction moved the following distances in 10 mins. : 
Oo, 3G, SO. Se, SS, BG, Be 88 AO SG) BR, se 
Mean = 0°376 centim. Mean galvanometer reading 32°9. Therefore y = 1:08/153. 
Temperature of water bath = 18°1. Area of tube = 0°442. 
Therefore 
v, = 0'000350 centim. per sec., 
which gives for the specific velocity of the calcium ion, moving through a decinormal 
solution of calcium chloride in agar jelly at 18°C., the value 
Voa = 0°000349 centim. per sec. 
For the corresponding aqueous solution KoHLRAUSCH gives 
Vcq = 0°000290 centim. per sec. 
The temperature coeflicient of the velocity was determined for these solutions by 
cooling the water-bath to 13°°2. 
Mean conductivity at 13°2 = 7°90 x 107%. 
Velocity = «34, -30, °34, -32, 34, °32) -32, :32, 32. Mean = 0324 centim. in 
10 mins. 
Mean galvanometer reading = 29°7. Therefore y = 1:08/175. 
Therefore 
v, = 0:000305 centim. per sec., 
which gives a temperature coefficient, at a mean temperature of 15°'7, of 2°78 per cent. 
per degree. 
Silver.—Decinormal jelly solutions of silver nitrate and sodium nitrate, the latter 
containing a little sodium chloride, gave in the resistance cell 
Silver nitrate at 17°4 = 171 ohms, 
Sodium _,, blige Aetna a 
Therefore mean conductivity at 17°°4 = 8°96 X 107%. 
MDCCCXCV.—A, 33 0 
