OF THE MINERAL WORK.

the cause of the fire, known to very few. In some places, entire mountains are found to be sulfurous, which cannot help but burn, whether ignited by the central fire, the elemental fire of lightning, or any other cause. And when a mountain of this kind has once begun to blaze with a flame already conceived, who shall extinguish the fire? No one, on account of the magnitude of the fire and the dangers of its accidents. Thus, left to itself, it consumes downward, never lacking matter suitable for the fire. If anyone, perceiving from the monuments of the ancients that mountains of this sort have burned for some centuries, or even beyond a millennium, wonders whence sufficient fuel is supplied for such a fire: let him know that it can conveniently happen that a mountain burns without intermission, not only because of the magnitude of the terrestrial globe—in which mountain wax original: "Cera montana" or bitumen, sulfur, and similar combustibles abound—but also because of the never-interrupted motion of the stars, by which they do not cease to stuff the earth with their effluvia and, besides minerals, to generate and to foster the fire and such combustible materials.

Many attempt to prove this by the fact that at stated times, lamentable wails are said to be heard near these mountains, which the credulous mob claims are the souls of the lost. But these are trifles. For those groans are only emitted when the mountains struggle to eject a great deal of fire, whereas they are otherwise burning and smoking gently. As soon as the inhabitants perceive these, they know well that they will shortly have a crop of ashes, fire, and stones from the mountain, and they strive to be in readiness so that they may escape the danger that the fire threatens.