Page:The Works of J. W. von Goethe, Volume 12.djvu/217

Rh Oct. 20, 1786.

Evening.

The whole of this bright and beautiful day I have spent in the open air. I scarcely ever come near a mountain, but my interest in rocks and stones again revives, I feel as did Antæus of old, who found himself endued with new strength as often as he was brought into fresh contact with his mother-earth. I rode toward Palermo, where is found the so-called Bolognese sulphate of barytes, out of which are made the little cakes, which, being calcined, shine in the dark, if previously they have been exposed to the light, and which the people here call, shortly and expressively, "phosphori."

On the road, after leaving behind me a hilly track of argillaceous sandstone, I came upon whole rocks of selenite, quite visible on the surface. Near a brick-kiln a cascade precipitates its waters, into which many smaller ones also empty themselves. At first sight the traveller might suppose he saw before him a loamy hill, which had been worn away by the rain: on closer examination, I discovered its true nature to be as follows: the solid rock of which this part of the line of hills consists is schistous, bituminous clay of very fine strata, and alternating with gypsum. The schistous stone is so intimately blended with pyrites, that, exposed to the air and moisture, it wholly changes its nature. It swells, the strata gradually disappear, and there is formed a kind of potter's clay, crumbling, shelly, and glittering on the surface like stone-coal. It is only by examining large pieces of both (I myself broke several, and observed the forms of both), that it is possible to convince one's self of the transition and change. At the same time we observed the shelly strata studded with white points, and occasionally, also, variegated with yellow particles. In this way, by degrees, the whole surface crumbles away; and the