In the operation of getting gold, the heavy work is assigned to the male negroes, and the lighter labor to the females. The cascalho, dug from these pits by the former, is carried away by the latter in gamellas, or bowls, to be washed. When a sufficient quantity has been procured, the men proceed to that process, which they perform much in the way already described in treating of S. Paulo. I perceived, however, that here they did not, in the first instance, attempt to separate the gold from the black oxide of iron, but emptied their gamellas into a larger vessel, by rinsing them in the water which it contained. The substance deposited in this vessel was delivered out, in small portions of about a pound each, to the most skilful washers, as the operation of washing, or, as it was termed, purifying it, required great niceness and dexterity. Some of the grains of gold were so fine as to float on the surface, and of course were liable to be washed away in these repeated changes of water; to prevent which the negroes bruised a few handfuls of herbs on a stone, and mixed the juice in small proportions with the water in their gamellas. Whether this liquid did in reality tend to precipitate the gold, I could not positively ascertain, but the negroes certainly used it with the greatest confidence.
There is another mode of separating the gold from the cascalho called canoe-washing, which is extremely interesting. The canoes are made in the following manner:—Two ten or twelve-inch planks, about twelve or fifteen feet in length, are laid on the ground, forming an inclined plane, sloping about one inch in twelve: two other planks of similar dimensions are fixed in the same direction at the lower end, forming a second inclined plane, with a fall of six inches from the former. On their sides are boards placed edge-wise, and staked down to the ground so as to form long shallow troughs, the bottoms of which are covered with hides tanned with the hair on, having the hairy side outwards, or, in defect of these, with rough baize. Down these troughs is conveyed the water containing the oxide of iron and the lighter particles of gold; the latter substance precipitating in its course is entangled by the hair. Every half hour the hides are taken up, and carried to a tank near at hand, formed of four walls, say five feet long, four broad, and four deep, and containing about two feet depth of water. The hides are stretched over this tank and well beaten, then dipped and beaten repeatedly, until all the gold is disentangled, after which they are carried back and replaced in the troughs. The tanks are locked up at nights, and well secured. The sediment taken from them being light, is easily washed away by the hand in the manner before described, leaving only the black oxide of iron, called esmeril, and the gold, which is so fine that mercury is used to separate it. The process, as I saw it performed, was as follows: About two pounds weight of oxide of iron, very rich in fine grains of gold, was put into a clean bowl; a quantity of mercury, about two ounces, was added to it; the mass of oxide, which was very damp, was worked by the hand for about twenty minutes, when the mercury appeared to have separated the esmeril, and to have taken up all the gold, assuming a soft doughy mass, that retained any form into which it was squeezed. The grains of gold, however, remained, not amalgamated with, but merely enveloped in the mercury. The mass was put into a folded handkerchief, and an ounce or more of mercury was wrung or squeezed from it. The rest was put into a small brass dish, covered with a few green leaves, and then placed over a charcoal fire, where it was stirred with an iron rod to prevent the gold from adhering to the sides of the dish. The leaves were occasionally changed as they became parched by the heat. When taken off, they exhibited, in some parts, small globules of mercury, and in others white oxide; on washing them with water, nearly half an ounce of the former substance was obtained from them[40]. I ever observed that the gold, after this operation, was changed in color from an agreeable soft yellow to a dirty brown, and presented a very different appearance from that which was not subjected to mercury.
By way of suggesting an improvement, I made some drawings and models of earthen vessels for evaporating, and afterwards condensing the mercury; but the quantity of gold in the hands of individuals requiring this mode of separation is so inconsiderable, that it would scarcely be worth their while to alter the process now practised.
I rode over various parts of the estate, and more particularly along both banks of the river, which, as well as the bed, appeared to have been much washed. The bends, or parts where eddies were formed, were the places noted as being rich in gold. Wherever the margin formed a flat, or level, the cascalho continued under the surface to some distance, appearing like a continuation of the bed of the river, which, in all probability, it was, as the river is known to have been much wider formerly. The parts that were then working, and others that had yet to be worked, bore a very unpromising appearance.
An opportunity was soon afforded me of carrying into execution the proposed dairy experiment. Having obtained about six quarts of milk, (which, on account of the scarcity of grass, was very poor), I put it into the culinary vessels that had been set apart for it; but such was the state of the place in which they were deposited, that that though I placed banana leaves over them, the surface next morning was covered with dust. I took off the cream in the best manner I could, but not being able to find a cellar or cold place for it to stand in, I was obliged to leave it in the same room with the milk, where it was hardly secure against the pigs. On each of the two following mornings, I obtained about two gallons of milk, which, being added to the other, was in due time churned; and, notwithstanding the disadvantages of poor milk, improper utensils, and bad keeping, a tolerably fair proportion of good butter was obtained. The people seemed highly satisfied with the success of the process; but I had strong doubts that they would not pursue it after my departure, as they must naturally dislike the trouble and care which it required. Such was the force of their habitual and long-cherished prejudices, that I have no hesitation in saying they would take ten times more pains to procure forty shillings-worth of gold, at an expense of thirty shillings, than they would to obtain forty-shillings worth of butter, though it were only to cost them five.
It may be expected that I should assign some reasons for entering so frequently into detail upon one of the simplest branches of rural economy. I have to observe, then, that ere I left Rio de Janeiro to undertake this journey, I was informed that the cheese generally consumed in that capital, and regarded there as a luxury, was the produce of the district to which I was going. Its taste was sometimes so extremely rancid and disagreeable, as to be utterly unwholesome, and from this circumstance I judged that there must be great mismanagement in the preparation of it. All the farms which I had occasion to visit on my journey to Villa Rica, and from thence to this place, fully confirmed my opinion; for, miserable as was the condition of every department belonging to them, that of the dairy was still worse. In the few places where they pretended to prepare milk for cheese, not only were the various utensils in an extremely filthy condition, but the rennet was so putrid as to be in the last degree sickening. I endeavoured to make the people sensible of the advantages of an improved mode of management, and wherever I had an opportunity, gave them information how to proceed; but as oral or written instructions were little calculated to make a durable impression, I determined, when leisure and convenience should concur, to enforce them by example. The first and only opportunity of this kind presented itself at the Fazenda do Barro; and I was the more induced to avail myself of it, from considering that the precedent which I wished to give to the farmers of the district, would have greater influence by being sanctioned by the approval of His Excellency the Conde de Linhares. The result, as I have just observed, was not very flattering to my hopes; a solitary experiment can do little towards reforming a general evil of long continuance; and there is no probability that this or any other branch of the farming system of the country will be improved, until the great and the opulent zealously unite for the accomplishment of an object so highly important.
In our excursions through various parts of the estate, we observed on the exterior of many of the trees a great variety of crimson lichens, which, on being steeped in water, imparted a very strong tinge of that color. Here were excellent barks for tanning, particularly that of a tree called Canafistula, which does not redden or color the hide. We found many beautiful varieties of the jacarandá, or rose-wood.
Having resided at Barro some days, we set out for the Fazenda de Castro, distant about seven miles, where we arrived, after a pleasant ride over a mountainous and finely-wooded district, containing large tracts of rich virgin land, watered by many excellent streams. This noble mansion was erected by the first possessor of the district, Senhor Mathias Barboza. It is very spacious and airy, having a gallery in front forty-eight yards long, to which open fourteen folding-doors, or windows, extending nearly from the top to the bottom of the rooms. It is situated near the confluence of the Ribeiro do Carmo and the Rio Gualacha, which form the San Jose, a river as large as the Thames at Battersea.
We did not rest above an hour at this fazenda, it being our intention to visit the aldea or village of S. José da Barra Longa, situated on the confines of the territory inhabited by the Buticudos Indians. Crossing the river by a fine wooden bridge, built about fifty years ago, but still in tolerable repair, we proceeded along the bank, which was embellished with several gardens, and presented more frequent appearances of cultivation than we had of late been accustomed to view. The climate is much hotter than at Villa Rica, on account of the lowness of the situation; and we were informed that fruits of every kind, particularly the pine, grew in this soil to great perfection in size and fineness of flavor. The truth of these accounts we could not ascertain, as this was not the fruit season.