Vol. VIII. Aphorisms. “If, before the discovery of the magnet, any one had said that a certain instrument had been invented by means of which the quarters and points of the heavens could be taken and distinguished with exactness ... it would have been judged altogether incredible ...” (pp. 141–142). “The ‘Clandestine Instances’--which I also call ‘Instances of the Twilight’ [the attraction or coming together of bodies]--and which are pretty nearly the opposite of ‘Striking Instances....’ The most remarkable ‘Striking Instance’ is the magnet ... a ‘Clandestine Instance’ is a magnet armed with iron; or, rather, the iron is an armed magnet ...” (pp. 224–226). “The polarity of the iron needle when touched with the magnet” (p. 261). “The magnetic or attractive virtue admits of media without distinction, nor is the virtue impeded in any kind of a medium” (p. 269). “There is no medium known by the interposition of which the operation of the magnet, in drawing iron, is entirely prevented” (pp. 285–286). “A piece of a magnet does not draw so much iron as the whole magnet” (p. 301). “As for the help derived from the virtue of a cognate body, it is well seen in an armed magnet, which excites in iron the virtue of detaining iron by similarity of substance; the torpor of the iron being cast off by the virtue of the magnet” (p. 311). “There are four virtues or operations in the magnet ... the first is the attraction of magnet to magnet, or of iron to magnet, or of magnetised iron to iron; the second is its polarity, and at the same time its declination; the third, its power of penetrating through gold, glass, stone, everything; the fourth, its power of communicating its virtue from stone to iron, and from iron to iron, without communication of substance” (p. 313). “But the flight of iron from one pole of the magnet is well observed by Gilbert to be not a flight strictly speaking, but a conformity and meeting in a more convenient situation” (p. 315). “The magnet endues iron with a new disposition of its parts and a conformable motion, but loses nothing of its own virtue” (p. 318). Vol. IX. In the fifth book of “De Augmentis Scientiarum,” these questions are asked: (1) A magnet attracts a solid piece of iron; will a piece of a magnet dipped in a dissolution of iron attract the iron itself and so get a coating of iron? (2) Again, the magnetic needle turns to the pole; does it, in so doing, follow the same course as the heavenly bodies? (3) And, if one should turn the needle the wrong way, that is, point it to the South and hold it there for a while, and then let it go; would it, in returning to the North, go round by the West rather than by the East? (pp. 75–76).