In no country are the molar stones[1] superior to those of Italy; stones, be it remembered, and not fragments of rock: there are some provinces, too, where they are not to be found at all. Some stones of this class are softer than others, and admit of being smoothed with the whetstone, so as to present all the appearance, at a distance, of ophites.[2] There is no stone of a more durable nature than this; for in general, stone, like wood, suffers from the action, more or less, of rain, heat, and cold. Some kinds, again, become deteriorated by the action of the moon, while others are apt to contract a rust in lapse of time, or to change their white colour when steeped in oil.

(19.) Some persons give this molar stone the name of "pyrites,"[3] from the circumstance that it has a great affinity to fire;[4] but there is also another kind of pyrites, of a more porous nature, and another,[5] again, which resembles copper. This last, it is said, is found in the mines, near Acamas,[6] in the Isle of Cyprus; one variety of it being of a silver, another of a golden, colour. There are various methods of melting these stones, some persons fusing them twice, or three times even, in honey, till all the liquid has evaporated; while others, again, calcine them upon hot coals, and, after treating them with honey, wash them like copper.

The medicinal properties which these minerals possess are of a calorific, desiccative, dispersive, and resolvent nature, and, applied topically, they cause indurations to suppurate. They are employed also, in a crude state and pulverized, for the cure of scrofulous sores and boils. Some writers mention another kind of pyrites also. Those among them have the greatest affinity to fire which we distinguish as "live"[7] pyrites. They are the most ponderous of all, and are found remarkably useful for advance-guards when laying out encampments; for, on being struck with a nail or any other kind of stone, they emit a spark, which, received upon sulphur, dried fungus,[8] or leaves, produces a fire almost sooner than it could be named.