The Subterranean World

by G. Hartwig

In order to stimulate almost superhuman exertions, an exorbitant salary was offered to all those who should venture to explore the most dangerous passages, and gather the quicksilver, which in some places had collected in considerable masses. But many paid for their greed with their lives, and for many months afterwards the air remained so noxious that the ordinary mining works could not possibly be carried on. To prevent similar accidents for the future, and also on account of the increasing scarcity of wood, the galleries have since then been walled with stone; but when we consider that the whole length of the subterranean passages amounts to no less than fifty miles, we cannot wonder that many of them are still propped with wood, and that as recently as 1846 fire raged in the mine, which was again quenched by putting part of it under water.

The stone galleries are vaulted, and of a masterly construction, seven feet high and six feet broad. The cost is less than one would suppose, as the progress of the mining operations furnishes the necessary materials.

The temperature in many galleries is equal to that of a conservatory; and if a floral hall, bathed in light and filled with delicious odours, is felt to be disagreeably hot, the warmth of the air is naturally far more intolerable in dismal excavations, where the workman pursues his laborious task by the weak glimmering of a lamp, and in an atmosphere full of deadly vapours.

Here, as in Almaden, a premature old age is the lot of the unhappy miners, who while young tremble like old men. Yet some attain a tolerably good old age, and he who reaches his forty-fifth year with trembling limbs is said to get accustomed to the effects of the poison, and may then live, or rather vegetate, till sixty or seventy.

Scarcely any animals live in the mines of Idria. Even spiders cannot long resist the noxious atmosphere. Rats, however, formerly existed there in considerable numbers, but have almost entirely disappeared since the last fire, which proved too much even for them. In some parts of the mine the mercury is inclosed in the clay-slate in extremely fine globules, so as scarcely to be visible to the naked eye; but on removing the ore many of them fall out and collect on the floor, in larger drops or small pools, which are carefully gathered in leather pouches or bags. By far the greatest part of the mercury of Idria, however, is combined with sulphur, and is obtained by distilling the ore in vast furnaces.

It may easily be imagined that the carriage of a liquid body of the weight of mercury requires the greatest care. The old mode of packing, still partly in use, is in sheep-skins, which can acquire the necessary firmness only by being tanned with alum, and are attentively examined before being used. After having been filled, the sack is first tried on a wooden table, and, having successfully stood the ordeal of severe pressing and punching, is enclosed in a second skin. Two of these packages, each containing forty-one pounds and a few ounces, are then placed in a small cask, and three of these in a square box. But as, in spite of all these precautions, the sacks will sometimes burst, the mercury is now frequently transported in large iron bottles, the stoppers of which are firmly screwed down by means of a machine invented for the purpose. All the quicksilver packed up in this manner is sent to Trieste, and thence chiefly to England, while that which is destined for Vienna and Germany is exported in sacks.

In the years 1856, 1857, and 1858, 4,570, 7,178, and 4,331 hundredweight of mercury were produced in Idria, and sold at an average price of one hundred florins. In 1850 mercury was worth two hundred and fifty florins the hundredweight, and thus we see how detrimental the competition of California has been to the Austrian treasury, which, in its chronic state of atrophy, is little able to bear any diminution of revenue.

A great part of the produce of the mines—about 1,000 hundredweight—is manufactured into cinnabar in Idria, which supplies almost all Europe with this splendid red colouring matter. All the other European quicksilver veins, in Tyrol, Bohemia, Hungary, and the Bavarian Palatinate, are utterly insignificant when compared with Almaden and Idria, as none of them produce more than a few hundredweight.

But even Almaden and Idria have lost much of their former importance since the discovery of the rich mines of New Almaden in California, which in 1865 yielded 4,000 hundredweight of mercury. As the uses of mercury are few, the falling off in price has been the consequence. But the greater cheapness of mercury has had a most favourable influence on the production of silver in Mexico, Peru, Bolivia, &c., as many of the poorer ores can now be profitably worked; and thus California, which by its gold placers threatened to disturb the relative value of the two precious metals, has, by promoting at the same time the production of silver, largely helped to maintain the former equilibrium and to relieve the fears of many political economists.

It is a remarkable circumstance that, while Europe has for the last three centuries received almost all its silver from America, Mexico and Peru were all the time dependent upon the old world for the mercury without which Potosi and Guanaxuato would have been comparatively unproductive. Quicksilver, it is true, had been found here and there, but the only mine of importance was that of Huancavelica in Peru, the discovery of which in the year 1567 is attributed to the Indian Gonzalo Navincopa, though, according to Humboldt, it was already known to the Incas, who made use of cinnabar to paint their cheeks, as Roman senators and Athenian archons had done before them. Here, at a height surpassing that of the Peak of Teneriffe by 1,500 feet, from 4,000 to 6,000 cwt. of quicksilver were annually obtained, until the folly of a director ruined the chief mine. Ever since 1780 Huancavelica had with difficulty supplied the growing wants of the Peruvian silver mines, for at a greater depth the ore was found to be mixed with sulphuret of arsenic, which greatly deteriorated its quality. As the lode forms an enormous mass, strong pillars had been left standing to support the roof, and these props the above-mentioned director had the improvident temerity to remove, in order to increase the produce of the mine. What anyone with a little experience or common-sense might have foreseen, took place. The rock, deprived of its supports, gave way, the roof fell in with a tremendous crash, and the mine was ruined—a memorable warning against the greed which, snapping at a shadow, loses the substance.