AQUEOUS AND ALCOHOLIC SOLUTIONS. 157 



mentally, that when a solution of dry iodide of potassium in rectified pyroxylic 

 spirit was placed in a tube A,* and water in a tube B, the two being connected 

 by asbestos, and A made negative and B positive by 50 pairs of 2-inch plates, 

 although iodine soon appeared in the neighbourhood of the positive pole in B, yet 

 it was accompanied by acid passing into the water of B; and, after forty minutes' 

 action, these appearances continued the same, only more decided, and without 

 any appearance of iodine elsewhere. There is little doubt that the nature of the 

 action was just the same as in aqueous and alcoholic solutions. 



In the whole circumstances, although the evidence may not be of quite so 

 decided a character in some of the cases of alcoholic solutions as in regard to 

 those in water, still I think there need not be much hesitation in laying down, as 

 a still more general proposition than that above stated, that " When solutions of 

 primary combinations of elementary substances in water, and in those liquids, 

 such as alcohol and pyroxylic spirit, which contain water as such as an essential 

 constituent, are submitted to voltaic agency, the dissolved substance is not di- 

 rectly decomposed by the current, but only the water of the solvent." 



III. Ethereal Solutions. 



Previous to my former communications, I had been unable to find any sub- 

 stance which, by solution in ether, led to any decided symptoms of decomposition 

 under voltaic agency, whether of the dissolved body or of the solvent ; and I was 

 thus led to expect that a general rule would be found to exist, by which both that 

 liquid and all bodies dissolved in it resist such agency. This led to the parti- 

 cular form which I formerly proposed provisionally for the general law on the 

 subject ; but I have since seen cause to strike ether out of the rule entirely, until 

 farther light can be thrown on the appearances which some of its solutions pre- 

 sent under electric action. 



I have found that, when highly rectified ether was saturated with dry muriatic 

 acid gas, and the solution submitted to the action of a moderate voltaic power, 

 elastic fluid was given off from the negative pole, and none from the positive, and 

 that the solution acquired a yellow colour, and, on subsequent evaporation, yielded 

 a little of a less volatile liquid, smelling of chlorine. The gas, when examined in 

 the voltaic eudiometer, appeared to be hydrogen, retaining some ethereal vapour 

 even after being washed with water, as a little carbonic acid resulted from the 

 detonation with oxygen. 



When dry hydriodic acid gas was conducted into ether, in a little WOLFE'S 

 Apparatus, the liquid immediately separated into two layers, a lower, dense, 

 and deep red, and an upper, slightly coloured, which, under voltaic agency, yielded 

 gas from the negative pole. 



* Fig. 1, PI. II., Edin. Trans, vol. xiv. 



