1825.] Electro*cMmical Theory tq Chemical Phc£7iomena. 263 



positive electricity of the hydrogen, and repel and consequently 

 liberate a portion of the negative electricity of the oxygen, and 

 hence the latter acquires a tendency to enter into fresh combi- 

 nations, and is more readily detached from the hydrogen bv 

 other bodies having an affinity for it. Thus many metals which 

 cannot alone take oxygen from water, decompose it rapidly by 

 the intervention of weak acids. 



Alkalies, on the contrary, being positively electrified, attract 

 the oxygen of water, and repel its hydrogen, during which a part 

 of the electricity of the latter is set free, and it thus acquires a 

 tendency to abandon the former. In this manner the hydrogen 

 of water combines with chlorine and iodine, which alone could 

 not take it from its oxygen, at least whilst all the physical condi- 

 tions remain unaltered. ,, ,, 



The prevailing chemical tWpry i^'wlipiiy insufficient to 

 explain rationally the influence of acids and alkalies in promot- 

 ing the decomposition of water in the cases above-mentioned. 

 It would be eri:oneous to attribute it to their affinity for the 

 oxides or acids about to be formed, for if we suppose the force 

 which tends to unite them to be inherent in the molecules, we 

 must admit that it can exert itself only when they are formed, 

 unless they be simple. This cause, therefore, can have no effisct 

 till that which is attributed to it has already been produced. It 

 is, in like manner, by diminishing the reciprocal action of the 

 elements of water by the attraction of one of them, and the 

 repulsion of the other, and thus setting free a part of their con- 

 cealed electricity, that acids and alkalies facilitate the decom- 

 posing powers of the voltaic apparatus; and hence also the 

 rapidity of its action is increased in proportion to their energy. 

 Salts dissolved in water, acting, as we shall presently see, as 

 acids or alkalies, produce analogous effects. 



Reciprocal Action of Acids and Oxides, 



ji,,When an acid combines with an oxide, if the free antagonist 

 electricities of their molecules be capable of mutually balancing 

 each other, it is evident that no change can ensue in the union 

 of their respective elements. But if that of one of them, the 

 positive electricity of the oxide, for example, be comparatively 

 feeble, the acid, from its predominating negative electricity, 

 causes its developement by attracting that element which is 

 endowed with it, and repelling the other; and this influence 

 may go so far as to determine their partial separation. Thus 

 many oxides are reduced to a lower state of oxidation by the 

 action of acids ; for instance, the deutoxide of barium is reduc^ed 

 to, the state of protoxide by the action of muriatic acid./ 

 ii (The alkalies, on the contrary, by their action on certain 

 i;>xides which perform the part of acids with respect to them, 

 separate a portion of the metal^ and raise the Remainder to a 



