r 



/r- ' ON HYPEROXIMUBIATE OF POTASH. SlJ 



form with eoth of them aa acid compound, (a difficulty 

 of which Mr. Davy is aware) observe to what an insurinount- 

 ab!e inconsistency this leads. We first of all account for 

 the decomposition of the muriatic acid in the retort by 

 an affinity between oxigen and hidroi^en superior to that 

 between hidrojjen and oximnriatic acid, and wt now account 

 for the forniution of the salts by an aftiuily between hidro- 

 gin and oximuriatic'acid superior to that between hidrogen 

 and oxit^en. This is a complete contradiction in terras, and 

 of course the hypothesis is untenable for a moment. 



This inconsistency, permit me to remark, appears upon Farther ano- 

 the ftjce of Mr, Davy's own memoirs. He ascribes the pro- ™*^y- 

 duction of water, when muriatic acid gas ii passed over 

 litharge, to the 8upe;ior affinity between oximuriatic acid 

 and iead^ and the consequent union of the hidrogen of the - - 

 one and the oxigen of the other*; and he accounts for the 

 oxide of tm and the muriate of ammonia, obtained by am- 

 monia, upon adding water to Libavius's liquor, by a supe- 

 rior aflFinity between oximvriatic acid and hidrugen'f. In the 

 first place water is cfoinposcd because the affinity of oximuri- 

 atic acid for a metal is greater than the quiescent affinities, 

 taken together, of oximuriatic acid for hidrogen and the 

 metal for oxigen; and in the se'cond, water is decomposed be- 

 cause the affinity of oximuridtic acid for a metal \s less than 

 the now dive! lent affinities of oximuriatic acid for hidrogen 



and the metal for oxigen, 



Now unless it can be shown, that the oximuriatic acid has 

 an affinity for lead very far indeed superior to what it has 

 for tin (which cannot be done, for the difference is on the 

 other side, and thus adding to the difficulty) it is plain, that 

 this is as complete a contrudiciion as that which we have 

 just noticed. 



1 should wish to enter more fully into this subject, but I 

 have already exceeded the limits which I had prescribed to 

 myself. At some future time 1 may resume the discussion. 



I trust, that what 1 have said may have this benefit, that 



it will lead to farther investigation, and thus prevent the 



too hasty adoption of an hypothesi*?, not yet sufficiently 



grounded upon facts and experiments, and the too incon- 



♦ See as above, js 326. \ V^* p. 327. 



siderate 



