The general introduction of the amalgamation of silver ores into Central Europe seems to have been very slow, and over 200 years elapsed after its adoption in Peru and Mexico before it received serious attention by the German Metallurgists. Ignaz Elder v. Born was the first to establish the process effectually in Europe, he having in 1784 erected a "quick-mill" at Glasshutte, near Shemnitz. He published an elaborate account of a process which he claimed as his own, under the title Ueber das Anquicken der Gold und Silberhältigen Erze, Vienna, 1786. The only thing new in his process seems to have been mechanical agitation. According to Born, a Spaniard named Don Juan de Corduba, in the year 1588, applied to the Court at Vienna offering to extract silver from ores with mercury. Various tests were carried out under the celebrated Lazarus Erckern, and although it appears that some vitriol and salt were used, the trials apparently failed, for Erckern concluded his report with the advice: "That their Lordships should not suffer any more expense to be thrown away upon this experiment." Born's work was translated into English by R. E. Raspe, under the title—"Baron Inigo Born's New Process of Amalgamation, etc.," London, 1791. Some interest attaches to Raspe, in that he was not only the author of "Baron Munchausen," but was also the villain in Scott's "Antiquary." Raspe was a German Professor at Cassel, who fled to England to avoid arrest for theft. He worked at various mines in Cornwall, and in 1791 involved Sir John Sinclair in a fruitless mine, but disappeared before that was known. The incident was finally used by Sir Walter Scott in this novel.
[13] Aurum in ea remanet purum. This same error of assuming squeezed amalgam to be pure gold occurs in Pliny; see [previous footnote].
[Pg 310][14] George, Duke of Saxony, surnamed "The Bearded," was born 1471, and died 1539. He was chiefly known for his bitter opposition to the Reformation.
[Pg 319][15] The Julian Alps are a section east of the Carnic Alps and lie north of Trieste. The term Rhaetian Alps is applied to that section along the Swiss Italian Boundary, about north of Lake Como.
[Pg 325][16] Ancient Lusitania comprised Portugal and some neighbouring portions of Spain.
[Pg 330][17] Colchis, the traditional land of the Golden Fleece, lay between the Caucasus on the north, Armenia on the south, and the Black Sea on the west. If Agricola's account of the metallurgical purpose of the fleece is correct, then Jason must have had real cause for complaint as to the tangible results of his expedition. The fact that we hear nothing of the fleece after the day it was taken from the dragon would thus support Agricola's theory. Tons of ink have been expended during the past thirty centuries in explanations of what the fleece really was. These explanations range through the supernatural and metallurgical, but more recent writers have endeavoured to construct the journey of the Argonauts into an epic of the development of the Greek trade in gold with the Euxine. We will not attempt to traverse them from a metallurgical point of view further than to maintain that Agricola's explanation is as probable and equally as ingenious as any other, although Strabo (XI, 2, 19.) gives much the same view long before.
Alluvial mining—gold washing—being as old as the first glimmer of civilization, it is referred to, directly or indirectly, by a great majority of ancient writers, poets, historians, geographers, and naturalists. Early Egyptian inscriptions often refer to this industry, but from the point of view of technical methods the description by Pliny is practically the only one of interest, and in Pliny's chapter on the subject, alluvial is badly confused [Pg 331]with vein mining. This passage (XXXIII, 21) is as follows: "Gold is found in the world in three ways, to say nothing of that found in India by the ants, and in Scythia by the Griffins. The first is as gold dust found in streams, as, for instance, in the Tagus in Spain, in the Padus in Italy, in the Hebrus in Thracia, in the Pactolus in Asia, and in the Ganges in India; indeed, there is no gold found more perfect than this, as the current polishes it thoroughly by attrition.... Others by equal labour and greater expense bring rivers from the mountain heights, often a hundred miles, for the purpose of washing this debris. The ditches thus made are called corrugi, from our word corrivatio, I suppose; and these entail a thousand fresh labours. The fall must be steep, that the water may rush down from very high places, rather than flow gently. The ditches across the valleys are joined by aqueducts, and in other places, impassable rocks have to be cut away and forced to make room for troughs of hollowed-out logs. Those who cut the rocks are suspended by ropes, so that to those who watch them from a distance, the workmen seem not so much beasts as birds. Hanging thus, they take the levels and trace the lines which the ditch is to take; and thus, where there is no place for man's footstep, streams are dragged by men. The water is vitiated for washing if the current of the [Pg 332]stream carries mud with it. This kind of earth is called urium, hence these ditches are laid out to carry the water over beds of pebbles to avoid this urium. When they have reached the head of the fall, at the top of the mountain, reservoirs are excavated a couple of hundred feet long and wide, and about ten feet deep. In these reservoirs there are generally five gates left, about three feet square, so that when the reservoir is full, the gates are opened, and the torrent bursts forth with such violence that the rocks are hurled along. When they have reached the plain there is yet more labour. Trenches called agogae are dug for the flow of the water. The bottoms of these are spread at regular intervals with ulex to catch the gold. This ulex is similar to rosemary, rough and prickly. The sides, too, are closed in with planks and are suspended when crossing precipitous spots. The earth is carried to the sea and thus the shattered mountain is washed away and scattered; and this deposition of the earth in the sea has extended the shore of Spain.... The gold procured from arrugiae does not require to be melted, but is already pure gold. It is found in lumps, in shafts as well, sometimes even exceeding ten librae in weight. These lumps are called palagae and palacurnae, while the small grains are called baluce. The Ulex is dried and burnt and the ashes are washed on a bed of grassy turf in order that the gold may settle thereon."
[Pg 334][19] Carbunculus Carchedonius—Carthaginian carbuncle. The German is given by Agricola in the Interpretatio as granat, i.e., garnet.
[Pg 336][20] As the concentration of crushed tin ore has been exhaustively treated of already, the descriptions from here on probably refer entirely to alluvial tin.
[Pg 348][21] From a metallurgical point of view all of these operations are roasting. Even to-day, however, the expression "burning" tin is in use in some parts of Cornwall, and in former times it was general.