No. 215 - THE PENNY MAGAZINE - Aug. 8, 1835

MINERAL KINGDOM.--SECTION XLII.

MERCURY--(concluded).

THE quicksilver-mines of Austria are situated at Idria, a mountainous district on the borders of Carniola, about twenty-five miles north-by-east of Tireste, and about the same distance west of Laybach, a place rendered celebrated in history by the congress of sovereigns held there in 1821. They are said to have been accidentally discovered about the end of the fifteenth century: a peasant wishing to soak a new pail in a rivulet, filled it with sand to sink it, and on raising it found it so unusually heavy that he carried some of the sand to the village pastor, who submitted it to the examination of the imperial director of mines. It was found to be a rich ore of mercury, and works were immediately begun, and have been constantly in operation since that period, yielding a large annual contribution to the imperial treasury. The chief ore is a bituminous sulphuret of mercury, that is, cinnabar mixed with bituminous and earthy matter, and it occurs in veins that traverse a limestone-rock. The mines, although 850 feet deep, are easily accessible, and quite dry, so that they are frequently visited by strangers, who suffer little inconvenience except from the fumes of quicksilver, which are disengaged from the ore even in the mine itself, and from the injury of any article of gold that may have been brought in contact with the mercury. Mr. Russell, in his 'Tour in Germany,' tells us that the miners have a story of two ladies who visited the mines during the Congress of Laybach, one of whom had her gold watch so amalgamated with quicksilver that it looked, when she came up, as if the case had been converted into tin; and the other had her fair cheeks and neck changed to the colour of a mulatto's skin, the sulphur combining with the white metallic powder with which she had sought to correct the natural dinginess of her complexion. In 1803 these mines unfortunately caught fire, and the conflagration raged to such an extent that they were completely abandoned. Attempts were made to smother the fire, but after awhile it burst forth like a volcano, shaking the ground all about, and shattering the adjoining houses like an earthquake. It could only be subdued by turning a stream into them, and thus completely drowning the works. The loss was immense, for, besides the destruction of the internal works, it was nearly three years before the water could be drained off and the operations resumed. For a long period the greater proportion of the produce was bought by the Spanish government for their South American mines, but that demand has nearly ceased, probably in consequence of the increased supply from their own mines at Almaden.

After the mines of Almaden and Idria, the most considerable in Europe are those in the ancient Palatinate, that part of the frontier-country of Germany and France on the left bank of the Rhine, westward of Worms. There are records of their having been worked in the thirteenth century, and they are supposed to have been opened long anterior to that period. They are situated in a hilly country, which forms the northern termination of the range of the Vosges mountains, extending about thirty miles from south to north, from Wolfstein to Kreutznach, and about twenty miles from east to west. The mines are in the coal-strata, coal being worked to a considerable extent in the country at different places; and the bituminous schist, which is rich in mercurial ore, frequently contains fossil fishes. These last are found abundantly near Munster-Appel, and are described by M. Agassiz, in his great work, now in course of publication, on that curious and important department of geological science--a naturalist from whose labours the most valuable general results regarding the history of the revolutions of our globe, in its progress towards its present condition, as disclosed by these organic remains, may confidently be expected. When the successful armies of the French Republic took possession of this territory, a commission of scientific men were sent to inquire into the state of the quicksilver-mines, and they reported that their annual produce amounted to about 67,000 lbs. of mercury.

The most celebrated quicksilver-mines of South America are situated in the mountain Santa Barbara, near the town of Guancavelica, about 150 miles south-east of Lima. They were discovered in 1566 by Henry Garces, a canon of the cathedral of Mexico, who examining one day a red earth, with which the Indians, like the ancients, painted their own bodies and their idols, found that it was cinnabar, from which he knew that quicksilver was obtained in Spain. The Peruvians had sought for silver in this place, but were quite unaware of the treasure it contained in the mineral so essential to them in refining the ores of their precious metals. The part of the mountains where the mines are situated is 12,300 feet above the level of the sea. The cinnabar occurs in the form of layers and of veins in a sandstone which is almost as compact as pure quartz, thirteen feet thick, forming a subordinate bed in a calcareious puddingstone, or rather breccia, that is, a rock composed of angular fragments of limestone, cemented together, resting upon or rather being a part of an extensive formation of magnesian-limestone. From documents which have been regularly kept of the produce of these mines, it appears that they had in general yielded annually from 400,000 to 600,000 lbs. of quicksilver, and in some years as much as 1,050,000 lbs. But in 1789 an ignorant superintendent, wishing to increase the produce, caused the miners to work the masses which had been left to support the roof, as is usually done in coal-mines; the consequence of which was, that, when the pillars were taken away, the roof of the mine sank down to the floor and closed it. (See 'Penny Cyclopaedia,' Article ANDES.) Ores of mercury are found in many other parts of the Andes, but not hitherto in great quantity. Humboldt says, that they exist abundantly in many parts of Mexico; but although they have for a long period required a large importation, when Humboldt was there mines had been opened only in two places, and even these were badly managed, and yielded a small quantity.

The method of obtaining quicksilver from cinnabar, which is by far the most common ore, is very simple. The ore, after being broken, carefully picked and reduced to powder, is put into an iron retort, with a proportion of quick-lime; a glass receiver is attached to the neck of the retort, and, by the application of a strong heat, the sulphur combines with the lime; the quicksilver is set free,--is distilled over and is collected in the receiver. A hundred pounds weight of ore yield in general from six to ten ounces of mercury.

Uses of Quicksilver.--The great consumption of this metal is in the refining of gold and silver ores by the process of amalgamation. It appears from Pliny and Vitruvius that this art was known to the ancients, and it was practised in Germany long before the discovery of the American mines. It was first practised in Mexico, and introduced from thence into Peru in the year 1557. The quantity of mercury used in the refining-establishments of Mexico at the time of Humboldt's visit was about 1,632,000 lbs. annually, and those of South America consumed about 918,000 lbs. A large quantity is imported into China for the same purpose. On an average of the fourteen years ending with 1828, the imports of quicksilver into Canton by the English and Americans amounted to 649,085 lbs. annually. The quantity imported into the several ports of the United Kingdom in the year 1833 was 1,597,866 lbs., and in the same year 1,166,137 lbs. were exported, and 260,158 lbs. cleared for consumption. With the exception of a small quantity from Germany, the whole amount imported was from Spain. The exports were to all parts of the world, but the largest proportions to Mexico, Chili, Peru, and different ports in India, including the Archipelago and China.

Mercury is extensively used in the arts, in various processes of gilding, and in jewellers' and silversmiths' works. In gilding, the gold is formed into a soft amalgam with mercury, and in that state is applied to the copper button, or other article; the mercury is driven off by heat, the gold remains behind, and is then burnished. One of the most extensive uses of it is for the manufacture of vermilion for paint, and for the colouring of sealing-wax. The quantity of quicksilver converted into vermilion in Paris amounts to about 40,000 lbs. annually, of which the greater part is consumed in the manufacture of sealing-wax. There is also a large consumption of quicksilver for the silvering of looking-glasses, which is done with tin-foil and a layer of mercury between it and the glass. The manufacture of barometers and other philosophical instruments must also require no inconsiderable quantity. The use of preparations of mercury in medicine is well known, especially in the form of calomel, which is a compound of mercury, oxygen, and muriatic acid; and a larger proportion of the acid forms corrosive sublimate, one of the most deadly poisons.