Ig6 ON OXIMURIATXC ACID. 



mutual hction of djiiuiuriatie acid and hidrogcn ; for, to 

 draw the concluwon from thnt experiment, \ve must, previ- 

 ously know what is the constftutioti of muriatic ncid «;as, 

 and what the constitution of oximuriaticacid ; and the roost 

 probable inferences with regard to these must reguUite the 

 conclusion that ought to be drawn. If there is reason to 

 "tj't^lieve, that the former is the real acid, and tliat the latter 

 IS a simple substance, it may be inferred, that muriatic 

 acid gas is a compound of oximnriatic acid and hidrogen. 

 But if there are facts whence it can beinferred, that muriatic 

 , Ipa^id gas contains water, or that oximuriatic acid contains 

 -^ Qxigen, the theory of the experiment must be given in con- 

 formity to these — the oxigeh 5f the oximuriatic acid com- 

 fciilng with the hydrbgeti, and forming water, which the 

 muriatic acid holds combined with it in the elastic form. 

 Thfre are facts from which these are the most direct and 

 j)ro5ai/<? conclusions; and these conclusions are avoided by 

 less direct, and more complicated and hypothetical assump- 

 tions. And it is merely an errour in logical deduction to 

 suppose, that such assumptions require no independent 

 proof, but are established because they would follow if the 

 ^inference were admitted, that muriatic acid is a compound 

 of oximuriatic acid and hidrogen. 

 Most obvious To somfi of the examples which I had given, illustrating 

 conclusjon nof^l^^ senerai'proposition, that the most obvious .conclusion 



always just. ^ . 



^from an experiment is not slvvays the just one, Mr. J. Davy 



'has stated some objections, which perhaps it is superfluous 



*to notice; for, were even the illustrations incorrect, the 



proposition itself cannot be denied, and it might be easily 



'illustrated by other examples, Ihe truth however is, that 



the exaniples I have given remain in full force. To one of 



^lhe"m indeed, that from the production of dry muriate of 



. " potash, no objection has been offered. With regard to the 



i»toduction of , other, that of the production of calomel by combining mu* 



calomel. .^^ * riafic acid'and oxide of mercury, there may be, as he sup- 



•'poses, aprOrluction also of water, (though this remains to be 



' prove<^) yet still the most direct inference from the experi- 



'mentls, that calomel is a compound of the oxide and acid ; 



' 'to»^ itis a mprc simple conclusion, that this water had been 



''d'ebc's»te*(l'^?om fJie acid, than that it had been formed *by 



^ *• - the 



