264 A VISIT TO THE PROVINCES 



tion. The former is then drawn off into a cavity beneath the floor, and poured into leathern or 

 buckskin bags, through whose pores the larger portion of the quicksilver rapidly filters, and a 

 silver as soft as putty remains. This being put into moulds, and subjected to pressure, another 

 portion of the mercury is forced out, and the remainder is finally driven off by evaporation. 

 For this purpose the pinas, as the moulds of metal are called, are placed under iron bells, rest- 

 ing on vessels of water within a furnace, and subjected to great heat. When all the quicksilver 

 has been expelled, the silver is quite porous, and may easily be indented with the finger-nail. 

 In this condition it is the plata pina* of commerce, though before exportation the metal has 

 latterly and very generally been formed into solid bars, after melting in other furnaces. 



The whole process occupies only from 24 to 36 hours, according to the durability and other 

 characteristics of the ores.- Very little of the quicksilver is lost. The portion driven off by 

 fire is received under the iron bells, and condensed in the water ; and that remaining with the 

 ground ores, having found no silver with which it could amalgamate, is afterwards washed out 

 when the earthy particles have all subsided, and the water has been drawn off. Some few years 

 since, one of the establishments, being short, borrowed a quantity of quicksilver from a native, 

 and poured the whole into tubs, with ores that had been brought from one of the mines in the 

 province of Coquimbo. At the end of the process, more quicksilver was found than had been 

 borrowed a fact no little surprising, until it was demonstratively ascertained that the vein 

 contained a combination of pure mercury and silver, amounting to 13^ per -cent, of the former 

 and 86^ per cent, of the latter metal. This metal has since been called arquerite, from "Ar- 

 queros," the name of the mine in Coquimbo where it was found. 



Prof. Domeyko says of this mineral :f "Disseminated in masses, sometimes filiform and 

 crystallized in regular octahedrons. Its color, silver-white ; the lustre, structure, and other 

 characteristics are the same as those of native silver, for which it was for a long time mis- 

 taken. Its specific gravity is 10.80. Under the blow-pipe it throws off sublimate of mercury ; 

 and, on the introduction of melted lead to it in a cupel, it throws off drops of silver, which 

 remain at the edge of the cupel. Dissolved in nitric acid, the application of muriatic acid pro- 

 duces a white precipitate, which blackens very little under the action of light. It is found in 

 great abundance in the silver mines of Arqueros, in Chile, which scarcely yield any other silver 

 mineral. Its gangue is sulphate of barytes, arsenate of cobalt," &c. 



The reader is referred also to the accompanying report, by Prof. J. Lawrence Smith, con- 

 taining an analysis of the specimens. brought home by the Astronomical Expedition. 



The relaves, as the earthy substances are called, sometimes contain as much as fifty per cent, 

 of sulphurets and arseniates of silver, and, when dried, were sold for export to England, there 

 being no smelting furnaces for silver ores then completed in Chile. TKere was one erecting at 

 the "Delirio" mine at the time of our visit, which was regarded to be as mad a scheme as 

 the project of working this very mine was pronounced to be some few years ago ; and a patent or 

 exclusive privilege was subsequently granted to an English gentleman, who proposed the erection 

 of other furnaces at Caldera and Coquimbo. Water and animals have hitherto served as motive 

 powers for the very simple machinery of the amalgamating mills ; but now that coal may be 

 transported on the railway from Caldera at comparatively reasonable rates, proprietors are 

 discussing the advantages of steam, and there is no doubt that the substitution will soon be 

 made. 



* Pine-apple silver, probably from the shape of the moulds into which it is passed from the leathern bags, 

 t Elementos de Mineralogia : Por Ignacio Domeyko. Serena. 1845. 



