CHAP. 44.—STONE OF SIPHNOS. SOFT STONES.

At Siphnos,[1] there is a kind of stone[2] which is hollowed and turned in the lathe, for making cooking-utensils and vessels for keeping provisions; a thing too, that, to my own knowledge,[3] is done with the green stone[4] of Comum[5] in Italy. With reference, however, to the stone of Siphnos, it is a singular fact, that, when heated in oil, though naturally very soft, it becomes hard and black; so great a difference is there in the qualities of stone.

There are some remarkable instances, too, beyond the Alps, of the natural softness of some kinds of stone. In the province of the Belgæ, there is a white stone[6] which admits of being cut with the saw that is used for wood, and with greater facility even. This stone is used as a substitute for roof-tiles and gutter-tiles, and even for the kind of roofing known as the pavonaceous[7] style, if that is preferred. Such are the stones that admit of being cut into thin slabs.

1. See B. iv. cc. 22, 23.

2. Ajasson identifies it with Ollar stone, talc, or soap-stone, a hydrous silicate of magnesia, and nearly allied to the Ophites of Chapters 11 and 30.

3. He being a native of that part of Italy.

4. The Green Colubine Ollar stone, or soap-stone of Italy.

5. See B. iii. c. 21.

6. Identified by Brotero with our Free-stone or grit-stone.

7. So called from its resemblance to the spots on a peacock's tail. He alludes, probably, to the mode of roofing with tiles cut in the form of scales, still much employed on the continent, and in Switzerland more particularly.