426 Dr. Faraday's Experimental Researches in Electricity. 



other electrode, although, from secondary action, it may not 

 make its appearance (7*3.). 



829. iv. A body decomposable directly by the electric cur- 

 rent, i. e. an electrolyte, must consist of two ions, and must also 

 render them up during the act of decomposition. 



830. v. There is but one electrolyte composed of the same 

 two elementary ions; at least such appears to be the fact (697.), 

 dependent upon a law, that only single electro-chemical equiva- 

 lents of elementary ions can go to the electrodes, and not multiples. 



831. vi. A body not decomposable when alone, as boracic 

 acid, is not directly decomposable by the electric current 

 when in combination (780.). It may act as an ion, going 

 wholly to the anode or cathode, but does not yield up its ele- 

 ments, except occasionally by a secondary action. Perhaps it 

 is superfluous for me to point out that this proposition has no 

 relation to such cases as that of water, which, by the presence 

 of other bodies, is rendered a better conductor of electricity, 

 and therefore is more freely decomposed. 



832. vii. The nature of the substance of which the electrode 

 is formed, provided it be a conductor, causes no difference 

 in the electro-decomposition, either in kind or degree (807. 

 813.); but it seriously influences, by secondary action (744.), 

 the state in which the ions finally appear. Advantage may be 

 taken of this principle in combining and collecting such ions 

 as, if evolved in their free state, would be unmanageable*. 



833. viii. A substance which, being used as the electrode, 

 can combine altogether with the ion evolved against it, is also, 

 1 believe, an ion, and combines, in such cases, in the quantity 

 represented by its electro-chemical equivalent. All the experi- 

 ments I have made agree with this view ; and it seems to me, 

 at present to result as a necessary consequence. Whether, 

 in the secondary actions that take place where the ion acts, 

 not upon the matter of the electrode, but on that which is 

 around it in the liquid (744.), the same consequence follows, 

 will require more extended investigation to determine. 



834. ix. Compound ions are not necessarily composed of 

 electro-chemical equivalents of simple ions. For instance, 

 sulphuric acid, boracic acid, phosphoric acid, are ions, but 

 not electrolytes, i. e. not composed of electro-chemical equiva- 

 lents of simple ions. 



* It will often happen that the electrodes used may be of such a nature 

 as, with the fluid in which they are immersed, to produce an electric cur- 

 rent, either according with or opposing that of the voltaic arrangement 

 used, and in this way, or by direct chemical action, may sadly disturb the 

 results. Still, in the midst of all these confusing effects, the electric cur- 

 rent, which actually passes in any direction through the decomposing body, 

 will produce its own definite electrolytic action. 



