178 Nature and Compofition of Muriatit Acid, " • 



On the Nature of Muriatic Acid. 



Two circumftances induced Citizen Bertholict to entertain fufpicions, and to invcdigate 

 the nature of this acid. 



The one is that which is announced in the Bulletin, No. 17, page 165, where M. 

 Humboldt fays, that muriate of iron is formed by the abforption of nitrous gas, by means 

 of fulphate of iron. 



The other, which had been obferved by Cavendifh, is the precipitation of nitrate of 

 filver into muriate, by the nitrite of pot-afli obtained from nitrate of pot-afii in part de- 

 compofed by fire. By adding to thefe obfervations the circumftance of the almoft in- 

 variable prefence of muriatic acid in every cafe where nitric acid is formed, and by 

 means of feveral other experiments carefully made, Citizen BerthoUet was led to the 

 difcovery of the nature of muriatic acid. 



He afcertained that nitrous gas does not precipitate the folution of filver. By repeating 

 -the experiment of Cavendiflr, with nitrate of pot-ath, he found it accurate, and was more- 

 over aflured that the precipitation could not proceed from the nitrous gas of the 

 nitrite ; for, 



I ft. Nitrate of lime does not produce the fame refult. 



2d, If a folution of iron be made in nitric acid, and it be fo managed as to load it with 

 this metal, little ammoniac is formed ; the folution becomes turbid, and it does not preci- 

 pitate the folution of filver. If a frefh quantity of iron be added to this folution, there is 

 an efFervcfcence, with a precipitation of almoft all the oxide of iron, the liquid contains more 

 ammoniac, together with muriatic acid, which is eafily demonftrable by the folution of 

 filver. If this liqu'd be diftilled, that which comes over contains nothing but ammoniac ; 

 the mui^atic acid remaining in the retort with part of the ammoniac. 



3d. Nitric folutions of tin, of zinc, of copper, made by heat, have fometimes yielded 

 muriatic acid. But it is to be remarked that this acid was more generally found in pro- 

 portion as the production of ammoniac was confiderable. 



In thefe experiments there are anomalies, the caufe of which citizen BerthoUet has 

 not yet been able to aflign. But they already prove that muriatic acid is formed under 

 thefe circumftances, and that its formation cannot be attributed to the prefence of pot-afli. 

 The principles of this acid muft therefore be fought for in water and nitric acid. 



Its incombuftibility, its refiftance to decompofition, prove, that if it contains hydrogen 

 and oxigcn, thefe two bodies are not predominant, for it is a principle of the theory of 

 affinities, that the difficulty of deftroying a compound is in proportion to the fmallnefs of 

 the quantity of one of its component parts. Almoft all the proportions of the combinations 

 of azote and oxigen are known. Citizen BerthoUet, therefore, fuppofes himfelf to be juftified 

 jn thinking that muriatic acid is a triple compofition of oxygen, of hydrogen in a fmall 

 quantity, and azote in a greater proportion. By adopting this opinion, the prefence of 

 muriatic acid, in a great number of chemical phenomena, is eafily explained. 



3 Thus 



