356 Researches on the rpvrlatlc Acid 



posited; and the residual gas contained about 44 of mu- 

 riatic acid gas, and the remainder was inflammable. 



MM. Gay Lussac and Thenard have proved by a copious 

 collection of instances, that in the usual cases where oxy- 

 gen is procured from oxvmuriatic acid, water is always pre- 

 sent, and muriatic acid gas is formed: now, as it is shown 

 that oxvmuriatic acid gas is converted into muriatic acid 

 gas by combining with hydrogen, it is scarcely possible -to 

 avoid, the conclusion, that the oxygen is derived from the 

 decomposition of water, and, consequently, that the idea 

 of the existence of water in muriatic, acid gas is hypothe- 

 tical, depending upon an assumption which has not yet 

 been proved — the existence of oxygen in oxymuriatic acid 

 gas. 



MM, Gay Lussac and Thenard indeed have stated an ex- 

 periment, which they consider as proving that muriatic acid 

 Vas contains one quarter of its weight of combined water. 

 They passed this gas over litharge, and obtained so much 

 water; but it is obvious that in this case they formed the 

 same compound as that produced by the action of oxymu- 

 riatic acid on lead; and in this process the muriatic acid 

 must lose its hydrogen, and the lead its, oxygen ; which of 

 course would form water : these able chemists, indeed, 

 from the conclusion of their memoir, seem aware that such 

 an explanation my be given, for they say that the oxymu- 

 riatic acid may he considered as a simple body. 



I have repeated those experiments which led me first to 

 suspect the existence of combined water in muriatic acid, 

 with considerable care; I find that, when mercury is made 

 to act upon one in volume of muriatic acid gas, by Voltaic 

 electricity, all the acid disappears, calomel is formed, and 

 about *5 of hydrogen evolved. 



With potassium, in experiments made over very dry mer- 

 cury, the quantity of hydrogen is always from nine to 

 eleven, the volume of the muriatic acid gas used being 20. 



And in some experiments made very carefully by my 

 brother Mr. John Davy, on the decomposition of muriatic 

 acid gas, by heated tin and zinc, hydrogen equal to about 

 half its volume was disengaged, and metallic muriates, the 

 same as those produced by the combustion of tin and zinc 

 in oxymuriatic gas,- resulted. 



It is evident from this series of observations, that Schecle's 

 view (though obscured by terms derived from a vague and 

 unfounded general theory) of the nature of the oxymuriatic 

 and muriatic acids may be considered as an expression of 

 i'actsj whilst the view adopted by the French school of 



chemistry, 



