112 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 



opposed to it in its ordinary chemical relations, i. e. if an anion be combined with a 

 cation, then both will travel, the one to the anode, the other to the cathode, of the 

 decomposing body (530. 542. 547.). 



828. iii. If, therefore," an iofi pass towards one of the electrodes, another ion must 

 also be passing" simultaneously to the other electrode, although, from secondary action, 

 it may not make its appearance (743.). 



829. iv. A body decomposable directly by the electric current, i. e. an electrolyte, 

 must consist of two ions, and must also render them up during the act of decompo- 

 sition. 



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 equivalents 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 de- 

 composable 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 elements, 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, I believe, an ion, and combines, in such cases, 

 in the quantity represented by its electro-chemical equivalent. All the experiments 

 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 investi- 

 gation to determine. 



834. ix. Compound ions are not necessarily composed of electro-chemical equiva- 

 lents of simple ions. For instance, sulphuric acid, boracic acid, phosphoric acid, are 

 ions, but not electrolytes, i. e. not composed of electro-chemical equivalents of simple 

 ions. 



* It will often happen that the electrodes used may he of such a nature as, with the fluid in which they are 

 immersed, to produce an electric current, 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 current, which actually passes in any direction through the decomposing 

 body, will produce its own definite electrolytic action. 



