[CHAP. V. Of the LOADSTONE.]
As for the Loadstone, it is not more wonderful in attracting Iron, than Beauty, which admirably attracts the Optick Perception of Human Creatures: and who knows, but the North and South Air may be the most proper Air for the Respiration of the Loadstone; and, that Iron may be the most proper Food for it. But, by reason there hath been so many Learned Men puzled in their Opinions concerning the several Effects of the Loadstone, I dare not venture to treat of the Nature, and Natural Effects of that Mineral; neither have I had much experience of it: but I observe, That Iron, and some sorts of Stone, are nearly allied; for, there is not any Iron, but what is growing, or is intermixt and united in some sorts of Stone, as that which we call Iron-stone. Wherefore, it is no wonder if the Loadstone, and Iron, should be apt to embrace one another.
[CHAP. VI. Of Bodies, apt to ascend or descend.]
There are so many several Causes that occasion some sorts of Creatures to be apt to ascend, and others to descend, as they are neither known, or can be conceived by one finite Creature: for, it is not Rarity or Density, that causes Levity and Gravity; but, the Frame or Form of a Creature's Exterior Shape, or Parts. As for example: A Flake of Snow is as Rare as a Downy Feather; yet, the Feather is apt to ascend, and the Flake of Snow to descend. Also Dust, that is hard and dense, is apt to ascend; and Water, that is soft and rare, is more apt to descend. Again, a Bird, that is both a bigger, and a more dense Creature by much, than a small Worm; yet, a Bird can flye up into the air, when as a leight Worm cannot ascend, or flye, having not such a sort of Shape. Also, a great heavy Ship, as big as an ordinary House, fraughted with Iron, will swim upon the face of the Water; when as a small Bullet, no bigger than a Hasle-Nut, will sink to the bottom of the Sea. A great Bodied Bird will flye up into the air; when as a small Worm lies on the earth, with a slow kind of crawling, and cannot ascend. All which is caused by the manner of their Shapes, and not the matter of Gravity and Levity.
[CHAP. VII. Why Heavy Bodies descend more forcibly than Leight Bodies ascend.]
Although the manner of the Shape of several Creatures, is the chief cause of their Ascent, and Descent; yet, Gravity and Levity, doth occasion more or less Agility: for, a Heavy Body shall descend with more force, than a Leight Body ascend: and the reason is, not only that there may be more Parts in a Heavy Body, than a Leight; but, that in a Descent, every Corporeal Motion seems to press upon each other; which doubles and trebles the Strength, Weight, and Force, as we may perceive in the Ascending and Descending of the Flight of Birds, especially of Hawks; of which, the weight of the Body is some hindrance to the Ascent, but an advantage to the Descent: but yet, the Shape of the Bird hath some advantage by the Weight, in such sort, that the Weight doth not so much hinder the Ascent, as it doth assist the Descent.