ON ELECTROLYSIS. 735 
and it is so unlike what we know of the behaviour of electrolytes in general 
that until proof to the contrary is forthcoming I feel compelled to believe 
that a current fairly starting in AC continues in it all the way, that a 
current starting in A’C’ likewise continues in that, and that secondary 
actions, or passage of current from AC to A/C’, only occur in the immediate 
neighbourhood of the electrodes.! 
It is easy to illustrate the preceding table of the changes in the 
solutions by a diagram of a special case :— 
Scheme of decomposition of sulphate of copper solution with platinum 
electrodes on the gratuitous assumption that water conducts + the whole 
current. 
Cathode Anode 
SCAU) Aaa ge ode: OpISOPERGec Te Ofeere CuSO DAsecus. ae « CuSO, 
H,0 H,0 H,0 H,O 7 
<Cus0o, CuSO, CuSO, Cusot 
Blais 7s 2 phen. t oledeiee | as Fi ste tetrened 2 H,O A 
<CuSO, CusOes esas CaSO. srchars « CuSO, 
H,O H,O H,0 Ho 6 
<CuSO,...... aS pt kecd.)t 2's CasOyes s|.2 5,» Cus, 
H,O H,0 : HO Ho A 
The arrangement of the symbols indicates the constitution before 
passing the current: the dotted lines and arrows indicate the state of 
affairs after four units of electricity have passed, on the arbitrary assump- 
tion (only made for the sake of illustration) that the CuSO, conducts 
three times as much current as the water does, z.e. that \ = 3? and )’= 1. 
Inserting these values in the previous table, and multiplying by four, to 
represent that four units of electricity have passed, it becomes :— 
Substance Loss peo Loss in anode vessel Total loss 
80, 13 -—14 0 
O 4 34 4 
Cu 24 13 4 
H, is > > 0 
CuSO, 2s 13 4 
H,O 3 34 4 
H,S0, -1 —3 —4 
1 Tt is assumed, in the text, that the ingredients of the liquid are thoroughly 
mixed. If they are purposely arranged in layers, free acid or free base may certainly 
make its appearance at the bounding surfaces. In fact, Faraday has observed the 
phenomenon, Exp. R. § 494; for he passed a current from strong MgSO, solution 
into ‘water’ (i.e., really weak MgSO, sol.) and found a deposit of magnesic hydrate 
at, the layer of demarcation. It is interesting to note that in January 1886 Kohl- 
rausch accepts this experiment as proving that water does in some cases share in the 
conduction, though he still considers its share as negligible in all but exceedingly 
weak solutions. 
