REFINING METALS. 2@7 



When the liquor is nearly saturated, the silver is 

 to be precipitated from it by common salt, which 

 forms muriate of silver, or luna cornea, easily re- 

 ducible to a metallic state, by melting in a cru- 

 cible, with a sufficient quantity of potash ; and 

 lastly, by refining the melted silver, if necessary, 

 with a little nitre thrown upon it. In this manner, 

 the silver will be obtained sufficiently pure, and 

 the copper will remain unchanged. Otherwise, 

 the silver may be precipitated in its metaUic state, 

 by adding to the solution of silver a few of the 

 pieces of copper, and a sufficient quantity of water 

 to enable the liquor to act upon the copper. 



Method of obtaining Gold in a pure State. 



Perfectly pure gold may be obtained, by dis- 

 solving the gold of commerce in nitro muriatic 

 acid, and precipitating the metal, by adding a 

 weak solution of sulphate of iron. The precipitate, 

 after being well washed and dried, is pure gold. 



Method of obtaining Silver in a pure State. 



Dissolve the silver of commerce in nitric acid, 

 and add to it some muriatic acid ; a white curdy 

 precipitate will be formed, which is muriate of 

 silver. To reduce muriate of silver to the metallic 

 state, let one part of it be mixed with three of 

 soda, and exposed to a white heat. When the 

 mixture is well fused, suffer it to cool j then break 

 the crucible, and separate the pure silvei' from the 

 muriate of soda which has been formed. 



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