Travels in the interior of Brazil, particularly in the gold and diamond districts of that country .. including a voyage to the Rio de la Plata, and an historical sketch of the revolution of Buenos Ayres . INTERIOR OF BRAZILS. 28$ if a negro were to be continually employed in agitatingthe water, the earthy matter would run off, leavingonly the gold and the ferruginous particles, which mightbe easily separated by mercury.* The utility of ma-chinery of this kind is too obvious to need pointingout Mills composed of three heavy irregular stones, re-sembling our flint-mills, would reduce many of the
Travels in the interior of Brazil, particularly in the gold and diamond districts of that country .. including a voyage to the Rio de la Plata, and an historical sketch of the revolution of Buenos Ayres . INTERIOR OF BRAZILS. 28$ if a negro were to be continually employed in agitatingthe water, the earthy matter would run off, leavingonly the gold and the ferruginous particles, which mightbe easily separated by mercury.* The utility of ma-chinery of this kind is too obvious to need pointingout Mills composed of three heavy irregular stones, re-sembling our flint-mills, would reduce many of theferruginous cementations and softer substances whichcontain gold. The matter thus reduced might be im-mediately washed by falling or being put into the in-clined planes before described, and would, no doubt,prove the means of obtaining considerable quantities ofthe precious metal, which would be otherwise might be useful where gold is found in hardand brittle substances; but these might be more effec-tually pulverized by a heavy stone rolling upon its edge,not unlike a tanners bark-mill In many instances, hand-sieves might be useful, andwould save much time and labour in washing, but p
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Keywords: ., bookauthormawejohn, bookcentury1800, bookdecade1810, bookyear1816
