We shall speak of the loadstone in its proper place,[1680] and of the sympathy which it has with iron. This is the only metal that acquires the properties of that stone, retaining them for a length of time, and attracting other iron, so that we may sometimes see a whole chain formed of these rings. The lower classes, in their ignorance, call this “live iron,” and the wounds that are made by it are much more severe. This mineral is also found in Cantabria, not in continuous strata, like the genuine loadstone, but in scattered fragments, which they call “bullationes.”[1681] I do not know whether this species of ore is proper also for the fusion of glass,[1682] as no one has hitherto tried it; but it certainly imparts the same property as the magnet to iron. The architect Timochares,[1683] began to erect a vaulted roof of loadstone, in the Temple of Arsinoë,[1684] at Alexandria, in order that the iron statue of that princess might have the appearance of hanging suspended in the air:[1685] his death, however, and that of King Ptolemæus, who had ordered this monument to be erected in honour of his sister, prevented the completion of the project.
CHAP. 43. (15.)—METHODS OE PREVENTING RUST.
Of all metals, the ores of iron are found in the greatest abundance. In the maritime parts of Cantabria[1686] which are washed by the Ocean, there is a steep and lofty mountain, which, however incredible it may appear, is entirely composed of this metal, as already stated in our description of the parts bordering upon the Ocean.[1687]
Iron which has been acted upon by fire is spoiled, unless it is forged with the hammer. It is not in a fit state for being hammered when it is red-hot, nor, indeed, until it has begun to assume a white heat. By sprinkling vinegar or alum upon it, it acquires the appearance of copper. It is protected from rust by an application of ceruse, gypsum, and tar; a property of iron known by the Greeks as “antipathia.”[1688] Some pretend, too, that this may be ensured by the performance of certain religious ceremonies, and that there is in existence at the city of Zeugma,[1689] upon the Euphrates, an iron chain, by means of which Alexander the Great constructed a bridge across the river; the links of which that have been replaced are attacked with rust, while the original links are totally exempt from it.[1690]
