242 OBSERVATIONS ON MURIATIC ACID. 



determine. When fulphuric, or even weaker acids, are poured 

 upon it, it gives out the ufual fmell of hyperoxigenized muri- 

 atic acid ; and the liquor becomes of an orange colour. This 

 is a fufficient proof, that corrofive fublimate is not a hyper- 

 oxigenized muriate of mercury, 

 park brown ox- I have juft mentioned that, in the formation of this fait, the 

 n 6 t uk^up 7 ox ^ e °f mercury, which was not diffolved by the acid, became 

 fuppofed to be of a very dark brown colour. I procured a portion of this 



different from oxId which f eemed different from the red oxide. It how- 

 the red oxide. . 



ever retained the form, and the cryltalline appearance, of the 



latter. It was foluble in nitric acid, without difengagement of 



gas ; and was precipitated from it, in a yellow oxide, by all the 



alkalis, except ammonia. It formed corrofive fublimate with 



muriatic acid; and the precipitate by the alkalis, was the fame 



as that from corrofive fublimate, made with the red oxide. 



Yet I am inclined to think, that the dark brown oxide differs 



in fome effential point from the red ; but I have not yet made 



fufficient experiments to prove this opinion. At all events, 



the prefent object being to examine the mercurial oxides only 



as combined with muriatic acid, it would be foreign to the 



purpofe, to enter into too minute an inveftigation of the other 



iiates of the metal. This, and fome other objects hinted at in 



this Paper, muft be referved for future inquiry. 



Hyper-ox. mur. In treating the earthy hyperoxigenized muriates with phof- 

 phate of filver, as I mentioned before, I obferved that the li- 

 quor fometimes contained in folution oxide of filver; which, 

 upon examination, I found to be combined with hyperoxigen- 

 ized muriatic acid. As the fait which is thus formed is differ- 

 ent, in every refpect, from fimple muriate of filver, it may be 

 of fome importance to confider it with attention. In the firft 

 place, it will afford the mod convincing proof of the difference 

 between muriatic and hyperoxigenized muriatic acid ; and, in 

 the next place, it particularly deferves to be remarked, for 

 poffcffing, in the moit eminent degree, one of the great cha* 



foluble in 2 parts racleriftic features of the genus to which it belongs. Hyper- 



cryftih'by'cold' ox 'g emzec ^ muriate of filver is foluble in about two parts of 

 warm water; but, by cooling, it cryftallizes in the fhape of 

 fmall rhomboids, opaque and dull, like nitrate of lead or of 



llightly fol. in barytes. It is fomewhat foluble in alcohol. Muriatic acid 

 decompofes it ; as does nitric, and even acetous acid : but the 

 reiult of this decomposition is not, as might be expected, nitrate 



or 



