298 Miscellaneous Intelligence. 



" The small or fine ores are ground in the Chilian mills in water, 

 which, as before stated, constantly passes off, carrying the finely ground 

 ore and earthy matter with it ; the gold, being freed from the matrix 

 or ore, is carried or precipitated to the bottom by its specific gravity. 

 One boy attends three mills a term of twelve hours ; at the end of every 

 twelve hours the mills are cleaned out, taking all the residuum of the 

 ore, which has been ground during the term, and which in each mill is 

 reduced to about three common buckets full, in which are the gold 

 and quicksilver, having formed an amalgam ; the gold which has been 

 freed falls to the bottom or bed-plates, comes in contact with the quick- 

 silver, for which it has a very strong affinity ; this residuum is placed in 

 a strong iron-bound box, sufficiently large to hold the contents of all the 

 mills for the twelve hours, and at the end of every twenty-four hours, 

 or two terms, is washed out, or rocked down in a machine for the pur- 

 pose, where the gold amalgamates, and the amalgam of gold and quick- 

 silver is obtained and washed clean, which is then strained through 

 buckskin or fine Nankeen, expressing all the superfluous mercury, 

 and leaving the amalgam of gold and quicksilver dry, and in a hard 

 ball. The same process is pursued with the residuum from the stamps, 

 or amalgamators ; these balls are then placed, in sufficient quantities, 

 in an iron retort, well luted, the lid or top secured by a strong iron 

 band and thumb-screw ; the retort is then placed in a small iron pot 

 or furnace, the mouth of the same being inserted in water. When 

 the temperature of the furnace is raised from 660° Fah., the mer- 

 cury or quicksilver escapes in vapor, and is condensed in a metallic 

 form in coming in contact with the water; after a short time, say thirty 

 or forty minutes, according to the mass and heat applied, the process is 

 complete — and, on opening the retort, the gold is found, if clean, of a 

 bright yellow color, but porous or spongy ; it is then placed in a cru- 

 cible, and melted with a little borax or potash, and, if impure, a little 

 nitre or saltpetre, is added. When completely fused, it is cast into an 

 ngot, and the work is complete, bringing out a beautiful bar which 

 usually weighs, when full, about 1000 dwts., and of a fineness of -985 

 or -9!)0 fine, or nearly nine per cent, finer than the coin of the United 

 States. The quantity of quicksilver used, and the annual loss in this 

 large establishment, is not over from two hundred and fifty to three 



i 



hundred pounds, at a cost of $1 20 to $1 50. The quantity of ore 



ground per day varies according to its quality or character, as hard or 



soft, quartz or slate, sulphuret or decomposed ores. The machinery 



is now sufficient to reduce a great quantity, and the engine, which is 



powerful, is capable of driving much more ; the engine cost $10,000 



to import from England. The whole establishment is built with a view I 



to permanency and usefulness ; the quantity of ore is, without doubt, 



inexhaustible; the ore varies somewhat in richness, but has always 



paid » great profit, as the whole establishment, machinery, buildings, 



also tools, horses, wagons, and carts, fall little short of the cost of 



$70,000, and have all been procured by the proceeds of the mines, as 



well as the purchase money of the property. Pieces weighing two, 



three, and four dwts. (the dwt. of gold from this mine is worth from 98 



to 100 c.) have been taken out as deep as from thirty to sixty feet, and 



from three to four pounds of the ore as much as sixteen to eighteen 



dwts, have been obtained by pounding and washing." 



