Though in every volcanic region of the globe sulphurous exhalations arise from a great number of craters or solfataras, yet sulphur is but rarely found in sufficient quantities to remunerate the miner’s toil. In this respect the island of Sicily is unrivalled, for no other country possesses such masses of this valuable, and in many cases indispensable, mineral.
The numerous sulphur pits of Sicily, which occur in crevices or hollows over a space of 150 geographical miles, are situated chiefly in the southern part of the island, in the districts between the sea-border of the province of Girgenti and the mountains of Etna, Mannaro, Castro Giovanni, and Catolica. They are no doubt the produce of a vast volcanic action which took place about the beginning of the tertiary period, when the sulphurous fumes, rising through countless clefts or fumaroles from the mysterious furnaces of the deep, condensed in the chalk and clay grounds of the superficial strata.
In former times, as long as the chief use of sulphur was confined to the fabrication of gunpowder, its production was comparatively insignificant; but since the manufacture of sulphuric acid has become a branch of industry of continually increasing importance, sulphur, the ingredient necessary to its formation, has considerably risen in value, and now constitutes the chief article of Sicilian exportation.
Girgenti, the most important town on the south coast of the island, though its dirty miserable streets and its 15,000 inhabitants form a melancholy contrast to the wealth and luxury of ancient Agrigentum, within whose lofty walls a population of 800,000 souls is said to have existed, owes to the increase of the sulphur trade the slight dawn of prosperity which has enlivened it during these latter years.
All the sulphur-pits in the south-west of the island send their produce to the port of Girgenti, and on every road one meets with long files of mules and asses loaded with sacks of sulphur.
The grape disease, against which this mineral is everywhere used in France and Italy as the only successful remedy, has given a new impulse to the sulphur trade by raising the price to about three times its former value. The merchants of Girgenti did not neglect this opportunity for making their fortunes, for as soon as the grape disease became a national calamity for the chief wine-producing countries, they bought up large tracts of sulphur-grounds, and thus acquired considerable wealth.
A visit paid by Dr. Häckel[[67]] in 1859 to the sulphur pits near Girgenti proves that mining operations in Sicily are still in the primitive condition described by all former travellers. Not even our commonest improvements are known; the pickaxe and the spade are almost the only implements employed, and with these the earth is excavated in the most slovenly manner, wherever a vein promises to be productive. The materials thus loosened from the rock are carried out of the mine in baskets and thrown into large heaps, from which the sulphur is extracted in the following wasteful manner. The conical mounds are covered with a mantle of moist clay, in which some openings are left for the emission of the smoke, and set fire to at the bottom. The melted sulphur collects in grooves or channels, and flows into square forms, where it congeals into a solid mass. This method, which is said to have been first introduced by the Saracens, causes, of course, a great loss of sulphur; but distilling ovens heated by coal have been found too expensive to answer. Dr. Häckel traversed one of the longest excavations, which was sometimes so narrow that he could only with difficulty pass, and then expanded into high vaults whose roof was ornamented with beautiful crystals of celestine and gypsum. The workmen were completely naked, on account of the oppressive heat which reigns in these pits; and their dark brown skins, sprinkled with light yellow sulphur dust, gave them a very strange and savage appearance. Most of the inhabitants of Girgenti are at present employed in the sulphur mines, and comparatively few are engaged in cultivating the beautiful gardens and fields that extend from the foot of the town to the sea, and occupy the site where once the ancient city of Agrigentum rose from the shore to the terraced hills which are still crowned with the ruins of her colossal temples.
On an average, the sulphur-ores of Sicily yield about sixteen per cent. of brimstone, and the quantity annually produced has increased from 94,985 tons in 1851 to 184,173 tons in 1866. Besides Girgenti, the chief ports from which sulphur is exported are those of Licata, Terranova, Siculiana[Siculiana], Palermo, Messina, and Catania.
One of the most remarkable events in the history of Sicilian sulphur mines occurred during the last century in the solfatara of Sommatino. This celebrated pit, which is situated on the precipitous right bank of the Salso Valley, took fire in 1787, through the negligence of the workmen, and as may easily be imagined from the inflammable nature of the materials, the conflagration caused the complete abandonment of the pit. After two years, however, during which the fire raged incessantly, the mountain suddenly burst asunder on its south-eastern flank, and a stream of melted sulphur, gushing forth from the cleft, precipitated itself into the neighbouring river. This phenomenon, which was evidently caused by Nature having performed on a vast scale an operation similar to that by which the sulphur is usually extracted from the ore, produced a mass of the purest brimstone, amounting to more than 40,000 tons, so that the owners of the pit, who had given up their property as totally lost, became enriched by the very circumstance which had seemed to menace them with utter ruin.
Next to the sulphur mines of Sicily, those of Teruel and Lorca, in Spain, which in 1862 furnished 12,639 tons, are the most considerable in Europe. The mines of Perticara di Talamella, in Italy, annually yield about 4,000 tons; and the Austrian sulphur pits of Swoszowice, near Cracovia, and of Radoboy, in Croatia, produced 1,867 tons in 1865.