jtf C&pmtca! P#c;ptfattoin 33 



fubfide. Upon the fame ground 5 Go!d 

 and Silver diflblved in their proper 

 Menftruums may be precipitated 

 with running Mercury 5 and if a So- 

 lution of blew Vitriol ( fuch as the 

 Roman, Eaftlndian^ or other of the 

 like colours ) be made in water, a 

 clean plate ot Steel or Iron being im- 

 merfed in it, will prefently be over- 

 laid with a very thin cafe of Copper- 

 which after a while will grow thick , 

 er $ but does not adhere to the iron 

 fbloofely as to be fhaken off, as the 

 Precipitated filver newly mentio- 

 ned may be from the Copper-plates 

 whereto it adheres. And that in 

 thefe operations the faline particles 

 may really quit the diflblved body, 

 and workf upon the Precipitant^ 

 may appear by the lately mentioned 

 praftice of Refiner /, where the Aqua- 

 fortify that forfakes the particles of 

 the filver^ falls a working upon the 

 copper-plates imployed about the 

 Precipitation, and diffolves fo much 

 of them as to acquire the greenifh 

 C 4 blett 



