ON SILVER. 371 



The Jimalgama, being subjected to distillation, gavemft 

 724, instead of 75|, which ought to have been the pro- 

 duct. I triturated the filings again with a little mercury, 

 and obtained 2-| more of silver, making in all 75. The 

 loss therefore was only -^^-^^ or four grains on the quan* 

 tity I had used, which was 1600 grains of muriat. - s 



The result shows, that with moderate quantities of 

 muriat the reduction may be made with ease, and without 

 any sensible loss. In the great it is still, more expedi- 

 tious, since all that is necessary is to place the muriat ^ / 

 upon lead in a cupel. 



The silver separated from the muriat by means of pot- The silver re^ 



ash, though well fused, is not always secure from retain- ducedby 



/.. T-. . 1 /. , .1 means of pot- 



mg some ot it. Jb orgmg one day a mass of about eight ash sometimes 



ounces, I \vas surprised to see it separate into laminaj retains muriat. 



under the hammer. On examining it, I perceived some 



, unreduced muriat between the plates. Mr. Fernandez 

 made the same observation, as Avill appear at the end of 

 this article. 



The muriat of silver frequently occurs among the mine- Native muriats 

 rals of America : it accompanies the native silver; and ^" •^"^"^^** 

 is found disseminated among the sul'phurets, carbonats, 

 and siliceous rocks, so as to be altogether imperceptible. 

 I examined an ore from the province of Caraccas, which Analysis of one 

 by tne application *of acids yielded me only 11 marks to from the Ca- 

 the hundred ; but having fused it with oxide of lead, pot- '■^"^'* 

 ash^ an J charcoal, it yielded a button, which left 19 

 faarfcsiathecttpel. This ore contained its riches in two 



' »te:telB9?in m«tal and in muriat. The silver of this ore 

 contained likewise a 36th of gold. Its matrix was sili- 

 ceous.; 



To discover the muriat, the ore should be boiled with Mode of dis- 

 ^rater, and a few filings of iron 'or of zinc: the muriat corcring the 

 will thus be decomposed,' and, after washing the ore, ni- 

 tric-acid »v:ill detect the silver. The muriatic lixivium 



, being precipitated with a solution of silver, the portion 

 <tf muriat of silver collected will be exactly equivalent to 

 that which existed in the ore. 



, Pieces of native muriat of the greatest purity are some- Very piurena^ 

 times brought from Peru. I have one that weighs about ^^^^ muriat 

 ten ounces^ the matrix of which is rhomboidal carbonat. 



This 



