Remember the Rainforest 1
he consults the widely translated Portuguese translation of Buchanan's "Domestic Medicine".
The next day we went to see the nearby gold mines on the mountain. Covered with dense vegetation, it follows from north to south, and is composed of the same clayey, greenish-gray, reddish and violet shale, as on the banks of the Rio das Velhas in Santa Rita. The strands of a compact, gray quartz, which contain
N.E. to S.W. At one point and another a mixture of alum and copper sulphate in the form of whitish gray powder flourishes in the stone. The mine consists of mines and pits, from which the rich gold material is extracted by means of explosives and hammering, which is brought down by the blacks with the grinding machine. These are very simple machines, and are located just below the streams, channeled from the top of the mountain to the bottom; next to each is a wash, that is, oxhair-covered spreads, in which the coarse material of the mineral is separated into crates with feet.
Gold wash in Minas
Along the stream, ox-hides are spread, with the hair up, to hold the golden dust, and from time to time they are shaken. However, so that both the coarser stones and the remaining gold dust are not lost, there are still several sieves and three large deep reservoirs. Crude stones are returned from the sieves to the machines, but the gold dust is collected by means of troughs that wash the processed mineral contained in the reservoirs. The owner of this mine wanted to insure himself in the establishment of his gold washing, against the loss of the precious dust with the scattered distribution of the washing and with more frequent manipulations, as the mineral passed from here to there.
In any case, the rigging is more effective here than that of most of the mines in this country, as a considerable portion of the very finest powder is still lost from other mines. The gold of the Padre Freitas mine,
Lavras de Congonhas, strip mining
like that of the Lavras de Congonhas and Itabira, because of the mixture with other metals, is only nineteen carats; However, the deposit compensates the owner with the profits from the mineral, and is considered one of the most productive in the province, because, they say, it has been yielding 50,000 cruzados annually in recent times. When we returned from the mine, we could not express our admiration to our lovely host for his impressive design and effective equipment. We will not stop praising, however, the advantages of the rotary washer and amalgamation, as it would be much more effective not to carry the mineral obtained,