264 M. F^r^^ ^^ pie 4/>p/f ea^/ofi of the [Oct . 



higher degre^ of 9xi^?ition. Thus potash causGvS protoxide of 

 tin to p^ to the state of deutoxide. In other cases, when tlie 

 alkalies ineVelylibcnite a portion of their positive electricity by 

 repulsion, they render them capable of absorbing a new quantity 

 of oxygen; such seems to be their action on the peroxide of 

 ipa^nganese. What has been said above of the influemce of acids 

 and alkalies on the decomposition of water is applicable to this 

 partial decomposition of metallic oxides by their agency. This 

 phenomenon appears equally inexplicable by ascribing it to a 

 pkAT of affinities, but it teaches us why metals cannot combine 

 witli acids, unless they be in the state of oxides. Since an acid, 

 wnose free electricity predominates greatly over that of an oxide, 

 Cannot unite with it without ehminating a portion of its oxygen, 

 so much the rather must a metal whose molecules possess the 

 full energy of their own electricity, when acting on an acid, tend 

 fo' separate its elements rather than combine with it direct, as 

 we often experience. Hence the necessity that its positive elec- 

 tricity should be partly neutralized by the negative electricity of 

 the oxygen before the combination c^n take efiect ;d 



^ 'In the same way, a fact somewhat embarrassing to the electrd^ 

 chemical theory may be easily explained ; namely, why the 

 capacity of saturation of oxides increases with the proportion of 

 oxygen. Their positive electricity being in the inverse ratio of 

 the proportion of that principle, we might suppose that the 

 quantity of acid necessary to saturate them should follow the 

 same ratio, but we find that as the proportion of oxygen in the 

 oxides increases, its negative electricity destroys, by repulsion, 

 a proportionately greater part of that of the acid, whose qua^tity> 

 Irir an equal quantity of metal, must thus increase in the r^liftjftf 

 the increase of that princip^..j^^ jj.^jjI^^ /jnornonedq ei£ sisdT 



^ All salts are hot soluole in water. An indispensable condi- 

 tion of solubility is their non-neutrality, for the one being a 

 neutral compound, another equally neutral can have no actioni 

 qi^ it. .But, it is not equally true that v^^e are to conclude that 

 because a salt, i itmu^t, therefore, be neutral, for the 



(johesion of^f^ij[^,plpcules may rj^j^4^5(;j^ji^i§i9tuWfi,i^tite»*f^^ 

 ^(^tneutrah _'^ mi . . ^ .■ -^/t-jJ byqolov )l) n')ift did 9vodf> 



XVlieji pne of these compounds, therefp^^,, dissolves in. wateil; 

 n^pcf^ j^p^^U acid or an alkaU by,,^ni?!Scj|^^lof positive i>r negok 

 tLve .^tefitrioityt £^nd,consequentlyjjfit^'?^(f|;so(Qne of its elemferits- 

 a^jixeD^l^itlie other. In this way we may account fbr* aiiacd,) 

 dpjt hitfi^rtO!|Satisfactorily explained by any theory, naraelyjntla«i 



t mutual decomposition of salts by the intervention of watetv 

 lyhen two saline solutions are mixed together, the element^- 

 ose repulsion has liberated a part of the electricity in the 

 solving liquid of one of them, must determine to that endowed 



