ON THF NATURE OF OXIMUHIATIC AC^O, f^S 



•rising from the confined and partial view he has taken of 

 the subject. 



All this 13 so obvious, that some apology is due to your 

 readers for having illustrated it at any length. This ha« 

 however been rendered necessary by the> tone this gen- 

 tleman has ussiuned through the whole of his observations. 

 He has held out the opinion of his brother as a genuine 

 theory resting on indubitable evidence, and has thought 

 himself at liberty to represent the reasoning I have employed 

 as mere speculation, and the explanations I have given as 

 uniformly hypothetical, and having on this account no pre- 

 tensions to be put in contrast with the others. He will now 

 perceive, that the subject may be presented under a different 

 light; and he will not perhaps again hazard the assertion, 

 that his brother's ** conclusions are not tainted by the slight- 

 est admixture of hypothesis." Least he should, permit me 

 to add one or two illustrations, which are besides not uncon- 

 nected with the subject. 



On adding to nitrate of mercury, muriate of soda, nitrate Decotapojitl- 

 of soda and calomel are forn;ed; chemists have therefore ^^^ " nitrate 

 been accustomed to conclude by rule's of evidence, which by inuriAt* rf 

 they thought sufficiently certain, that the nitric acid com-***"^* 

 bines with the soda, and that the muriatic acid combines with 

 the mercurial oxide, forming the calomel. According to Mr, , 



Davy's opinion however, though the nitric acid unites with 

 the soda, the muriatic acid does not unite with the oxide, 

 but these substances decompose each other, the oxigen of 

 the oxide unites with the l^idrogen of the acid and forms 

 water, and the calomel is a compound of oximuriatic acid 

 and metallic quicksilver. Again, on adding muriatic acid Murbtic 

 to potash we form muriate of potash, and on exposing this ash, ' 



product to heat, so as to obtain it dry, we have hitherto be- 

 lieved, apparently on very strict induction, that the water 

 was expelled, and that the dry product is a compound of 

 muriatic acid and potash. But in Mr. Davy's new sys- 

 tem it is supposed, that the acid and the potash decompose 

 each other, the oxigen of the one and the hidrogen of the 

 other combine and form water, leaving a compound of oxi- 

 muriatic acid and potassium. On dissolving this in water 

 aew changes occur, the water is decomposed) the potassium 



receivet 



