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Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica

Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica Page of 251 Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica Text size:minus plus Restore normal size   Mail page  Print this page
BOOK V
107
in Hesse. Some stones are given a square form after quarrying, for example the Naxian stones from the marble quarries and the stones from the Armenian quarries. Recently a few water stones have been fashioned into triangular shapes about six inches long. These are found near the Krakow fortress in Bohemia and consist of wood that has been turned into stone. Only the largest blocks are shaped into the form of a drum and used with water to sharpen tools, being turned either by a water wheel or by a man. Mill-stones are made from large and hard blocks. Some are made from the black and white banded rocks brought from Lower Germany and from the stones that have the appearance of broken bones. These latter are called ίνούοωτ by the Greeks. All of these stones can be used to sharpen iron and some of the hardest are used as hearthstones, for example, in Hesse. Finally, since an edge is restored to iron by water stones through a wearing away of each it follows that whetstones are cooling and there­fore when spread over the breasts of a virgin or the testes of a young boy will stop their growth. Whetstone is useful for the gout. Since an oil stone restores an edge to iron because the iron is worn away it follows that the stone cleanses and, for that reason, is used as an ointment to stop falling hair. The Greeks call this disease alopecia.33
Gold and silver are tested on coticula (touchstone). The reason for this will be given in the book De Re Metallica. This stone is called βάσανος by many Greeks, for example, Pindarus, Sophocles, Antiphon and Theog-nides because the quality of the gold can be determined from its streak as well as with a balance. For the same reason others have called the stone χρνσΐτίς. Some call it lydius stone because it is found in Lydia; others heracleus stone from the town of Heraclea in Lydia. All touchstone in the time of Theophrastus was found in the Tmolus river, in the time of Pliny in a number of places and today we get our touchstones from the rivers of Hildesheim and Goslar and from the town of Visa between Egra and Eredorf. Usually it is very dark with a characteristic smoothness. Although Pliny writes that the largest is less than four inches long by two inches wide it is found today six inches long and three inches wide and even larger, especially near the village of Visa. Theophrastus writes that ex­perience has sho\vn that the stone which has been partially exposed to the sun is the best while that which has lain in water is inferior because it is not as dry as the former. Moisture prevents the stone from taking the color of either gold or silver. A good test cannot be made when the stone is hot for then the moisture that is given off acts as a lubricant.
Pumex (pumice) is found in localities that have been on fire at some time or are burning now. It has been melted down from earth or stone and changed into its present form. Typical pumice is found on Mt. Moderna and Mt. Vesuvius in Campania; on the islands of Ischia and Aeoliae; in Sicily near Aetna; on Melos and Nisida and on the sun-baked hills of
38 From the Greek άλώττηζ, a fox. Mange and loss of fur is very common among foxes.
Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica Page of 251 Book V about lodestone, hematite, geodes, hematite, selenite, lapis secularum, asbestos, mica
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