ON PYROXYLIC SPIRIT, &o. I33 



any smell of chlorine observed after action, for three quarters of an hour. In the 

 latter experiment a little metallic zinc was deposited on the negative foil, from a 

 small quantity of the solution having passed into A by capillary action, as was 

 ascertained by reactives. 



With aqueous solutions of chloride of potassimn of various strengths in B, 

 and water in A and C, there was, after a time, strong acid reaction in the solu- 

 tion in B, whilst at the positive pole, and on the intermediate asbestus, the reac- 

 tion continued slight, and there was no bleaching action or decided smell of chlo- 

 rine any where after an hour's action. 



In aU cases in which the acid which had passed into C, where solutions of 

 chlorides were acted on, was examined, it was found to be muriatic. 



The leading/acte which have thus been observed are these : First, When alco- 

 holic solutions of chlorides and iodides are acted on in the circumstances men- 

 tioned, no acid is observed to be produced in the alcoholic solutions. Secondly, 

 When aqueous solutions of these substances are employed, the corresponding hy- 

 dracids are produced in the solutions. Thirdly, When alcohoUc solutions are 

 used, the corresponding hydracids are produced at the point of contact between 

 the alcoholic solutions and the water with which they are connected. Fourthly, 

 The hydracids arising in both these ways, are carried to the positive pole situated 

 in the water. 



Such apparently being the facts, let us see whether they are capable of ex- 

 planation on the idea of chlorides and iodides being dissolved as such in water ; 

 and let us take the different cases which may be assumed. Let us iirst suppose 

 that water only is du-ectly decomposed in the aqueous solution, and that, accord- 

 ing to the usual and most approved view of electric action, a series of decomposi- 

 tions and recompositions of the directly decomposed body ensues, until its ele- 

 ments arrive at then- respective poles. On this view we evidently cannot explain 

 the production of acid in the aqueous solution under the described circumstances 

 of the experiment. Let us next suppose that the chloride or iodide alone is di- 

 rectly decomposed, and that its elements proceed in the above way to their proper 

 poles. Precisely the same objection applies to this view. Lastly, Let us suppose 

 that both water and chloride or iodide suffer decomposition, and that either the 

 elements going to the same pole unite on their journey, or, by a mutual inter- 

 change, the electro-negative constituent of the water unites with the electro-posi- 

 tive of the salt, and the electro-positive of the water with the electro-negative of 

 the salt. The former of these alternatives is contradicted by the fact, that the 

 acid passing to the positive pole is the hydracid and not the oxyacid ; and the 

 second is not only at variance with the usual view, that the elements of substan- 

 ces under voltaic decomposition foUow the road of themselves to their proper poles, 

 by a series of decompositions and recompositions ; but is not in accordance with 



