The diamond is a stone possessed by many among ourselves, especially by jewellers and lapidaries, and the stone is so hard that it can be wrought neither by iron nor fire, nor, they say, by anything at all except goat's blood. But do you suppose it is as much admired by those who own it and are familiar with its properties as by those to whom it is shown for the first time? Persons who have not seen it perhaps do not believe what is said of it, or if they do, they wonder as at a thing beyond their experience; and if they happen to see it, still they marvel because they are unused to it, but gradually familiar experience [of it] dulls their admiration. We know that the loadstone has a wonderful power of attracting iron. When I first saw it I was thunderstruck, for I saw an iron ring attracted and suspended by the stone; and then, as if it had communicated its own property to the iron it attracted, and had made it a substance like itself, this ring was put near another, and lifted it up; and as the first ring clung to the magnet, so did the second ring to the first. A third and a fourth were similarly added, so that there hung from the stone a kind of chain of rings, with their hoops connected, not interlinking, but attached together by their outer surface. Who would not be amazed at this virtue of the stone, subsisting as it does not only in itself, but transmitted through so many suspended rings, and binding them together by invisible links? Yet far more astonishing is what I heard about this stone from my brother in the episcopate, Severus bishop of Milevis. He told me that Bathanarius, once count of Africa, when the bishop was dining with him, produced a magnet, and held it under a silver plate on which he placed a bit of iron; then as he moved his hand with the magnet underneath the plate, the iron upon the plate moved about accordingly. The intervening silver was not affected at all, but precisely as the magnet was moved backwards and forwards below it, no matter how quickly, so was the iron attracted above. I have related what I myself have witnessed; I have related what I was told by one whom I trust as I trust my own eyes. Let me further say what I have read about this magnet. When a diamond is laid near it, it does not lift iron; or if it has already lifted it, as soon as the diamond approaches, it drops it. These stones come from India. But if we cease to admire them because they are now familiar, how much less must they admire them who procure them very easily and send them to us? Perhaps they are held as cheap as we hold lime, which, because it is common, we think nothing of, though it has the strange property of burning when water, which is wont to quench fire, is poured on it, and of remaining cool when mixed with oil, which ordinarily feeds fire.