GVILIEL. GILBERTI

catchword: are

by nature, he stirs up nothing but errors and fog in such an excellent field of knowledge. Fortunius Affaitatus philosophizes quite ineptly about the attraction of iron and its turning toward the poles. Most recently, Baptista Porta, a philosopher of no common sort, made his seventh book in his Natural Magic a storehouse and repository of the marvels of the magnet; but he knows little about magnetic motions, nor has he ever seen them. And some things about manifest forces, which he either learned himself from R. M. Paul the Venetian or drew from his own night-watches, are not so well discovered or observed; rather, they swarm with the most false experiments, as will appear in their proper places. I judge him worthy of much praise, however, because he undertook such a matter (as he did many other things quite happily and with no small profit) and because he gave occasion for further searching. All these who philosophized before us, relying on a few vague and uncertain experiments, philosophizing about attraction based on reasons drawn from the hidden causes of things, and then seeking—in the causes of magnetic directions—the part of the sky, poles, stars, constellations, or mountains, crags, void, atoms, attractive or respective places outside the sky, and some unproven paradoxes of this kind; they wander completely lost and roam blindly. We do not yet intend to tear down those errors and their impotent little arguments, nor the many other fables about the magnet, nor the superstitions of impostors or fabulists. For instance, the doubt of Franciscus Rueus about the magnet: whether it is the imposture of evil spirits. Or that, when placed under the head of an ignorant woman in her sleep, it drives an adulterer from the bed. Or that the magnet is useful to thieves through its smoke and odor, as if the stone were born for thefts. Or that it opens wild beasts and locks, as Serapio deliriously claims. Or that iron pulled by a magnet, when placed on a scale, adds no weight to the magnet, as if the gravity of the iron were absorbed by the power of the stone. Or that which Serapio and the Moors report: that in India there exist certain maritime crags, abundant in magnet, which extract all the nails from ships approaching them and bring the vessels to a halt—a fable that Olaus Magnus does not omit, who says that there are mountains under the north of such attractive power that ships are built with wooden nails, lest they be pulled from the wood by the iron nails while passing through the magnetic rocks. Nor that a white magnet can be sought for a love potion. Or, as Hali Abas inconsiderately recites, that if it is held in the hand, it will cure pains of the feet and spasms. Or that it makes one pleasing and acceptable to princes, or eloquent, as Pictorius sang. Or that Albertus Magnus teaches that there are two kinds of magnets: one that directs toward the North, and another toward the South. Or that iron is directed toward the northern stars by a power communicated by the polar stars, just as they follow the sun.