(Alluded to in the Gilbert A.D. 1600 Article, p. 83)
Book I. chap. iii. The loadstone ever has and ever shows its poles, which look toward the poles of the earth and move toward them and are subject to them.
Book I. chap. vi. The loadstone attracts iron ore, as well as the smelted metal, the best iron, acies, being the most readily attracted.
Book I. chap. ix. Iron ore attracts iron ore.
Book I. chap. x. Iron ore has and acquires poles, and arranges itself with reference to the earth’s poles.
Book I. chap. xi. Wrought-iron, not magnetized by the loadstone, attracts iron.
Book I. chap. xii. A long piece of iron, even not magnetized, assumes a north and south direction.
Book I. chap. xiii. Smelted iron has in itself fixed north and south parts, magnetic activity, verticity, and fixed vertices or poles.
Book II. chap. ii. Not only do amber and jet attract light substances: the same is done by the diamond....
Book II. chap. ii. When the atmosphere is very cold and clear, the electrical effluvia of the earth offer less impediment.