Passage of Electricity through Liquids. 



289 



The following Table gives the intensities of the current (mea- 

 sured by the multiplier) and the deflections of the electrometer 

 when the given length of liquid / is interposed between the elec- 

 trodes. In observations 5, 6, and 7, 79 mercury units were in- 

 terposed, besides the necessary conducting-wires, between the 

 multiplier and the battery : — 



No. 



/. 



Multiplier. 



Electrometer. 



i. 



Mean. 



u — v. 



Mean. 



1. 

 2. 

 3. 



4. 

 5. 

 6. 

 7. 



CO 



320 millims. 

 160 „ 



90 „ 

 320 „ 

 160 „ 



90 „ 



107-2 



2108 



377 



102-5 



211-9 



372-2 



105-7 

 209-7 

 376-9 

 101-8 

 211-8 

 370-2 



106-4 



210-2 



377 



1021 



211-8 



371-2 



252 



248 



249 



249 



248-5 



248-7 



246 



-247 

 -246 

 -246 

 -246 

 -245 

 -244 

 -245 



249-5 



247 



247-5 



2475 



246-7 



246-3 



245-5 



The electrometer shows almost the same deflection with dif- 

 ferent lengths of the interposed thread of liquid, as was to be 

 expected from equation (4) (§ 60). 



When Wollaston's electrodes of cadmium wire coated with pa- 

 raffin were dipped into the alcoholic solution of iodide of cadmium 

 at a distance of 35 millimetres from one another and connected 

 with the pairs of quadrants of the electrometer, the deflection of 

 the latter was 26*75 divisions of the scale; whilst when the cad- 

 mium plates were at the ends of the column of liquid 320 mil- 

 lims. long, a deflection of the electrometer of 243 divisions was 

 observed. 



The deflection of the electrometer remained the same whether 

 Wollaston's electrodes were placed on the edge, in the middle, 

 or on the side of the column, and almost perfectly agreed with 

 the value 26*8 calculated theoretically. 



So far as the accuracy of the method of observation reaches, 

 all these experiments show that an alcoholic solution of iodide of 

 cadmium behaves, as regards the distribution of free electricity 

 when a constant current traverses the liquid, like metallic resist- 

 ances of equal magnitude, or like ordinary liquid electrolytes, 

 such as aqueous solution of sulphate of copper. 



§69. 



It is a further question whether the current in the solution of 

 iodide of cadmium and in the metallic part of the conduction 

 had the same intensity. 



To determine this, a straight glass tube 20 miUims. in dia- 

 meter was filled with the alcoholic solution of iodide of cadmium 



Phil. Mag. S. 4. Vol. 44. No. 293. Oct. 1872. U 



