368 ON SILVER, 



is decomposed by diluting it with water, and the mnriat 



is precipitated. 



MurJatlcacid This acid, poured on parted silver, attacks it, converts 



'°r^* * "^""^^ it into a miiriat, and a eas is^evolved, which forces th* 

 With pure sil- , „ , , , ,»i, . ■, i ,^ 



yer, andhi- cork out of the bottle. I his gas can be no other than 



drogcn is given hidrogen. The acid, which is weakened, holds scarcely 

 any thing in solution, for hidrosulphurated water scarcely 

 changes its colour. 



That Bergman should announce this muriat as aconi- 

 pound of 75 pa^ts of silver and 25 of acid, Was very 

 excusable; but that moderns, certainly not unacquainted 

 with the term of OTiidatiouj should repeat this — Hav« 

 they forgotten the oxigen ? 



Muriat of sll- Themuipiat of silver does not penetrate the crucibles, " 



!^^J -,,?'il!!?L «r even their surface. Itdoes not atft upon them, 

 act on the cru- ^ 



cibles. I did not perceive that it was volatile. During th« 



Is not volatile. first rmprcssiOn of the heat only, and by the assistanceof 

 tlie moisture present, a vapour escapes, which is con- 

 densed in the empty crucible inverted over it. This sub- 

 limate, as Stahl observed, has the appearance of pow* 

 dered arsenic ; but When the muriat is in fusion, no mopt 

 vapour escapes, audit remains fixed at the bottom of the 

 crucible. Four drams of fused muriat were kept at a 

 •fnodcratc red heat for half an hour in a covered Hessian 

 Gjfucible. The crucible, on coming out ^of the fire, had 

 lost 6 grains : but it was only because a little of 'thd 

 muriat had made its way through one of those flaws, 

 which frequently occur in them if the paste were not 

 very carefully kneaded before it was applied to the. 

 wheel. 

 _ Half an ounce of the same muriat, heated the sam^ 

 time in a luted retort, did not attack the glass, or give 

 the slightest indication of sublimate. Sage observed the 

 same. 

 Transparent, The muriat heated to this point is transparent; and has 

 ofapearly a pearly grey hue,. by which it is distinguished. With 



«kYtlK native *^^^^^1^P*^^^^"^^ ^* ^^^^ perfectly like the native muriat, 

 tnuriat. thatit is impossible not t6 confound them together; so 



true it is, that Nature has not two scales for these com- 

 binations. 

 Crystallizes in The muriat has a decided tendency to crystallize in 

 octahedrons. ' octahedra. 



