_A._ Thinking upon what you said yesterday, it looked like a generation of living creatures. I saw the love between the loadstone and the iron in their mutual attraction, their engendering in their close and contrary motion, and their issue in the iron, which being touched, hath the same attractive virtue. Now seeing they have the same internal motion of parts with that of the earth, why should not their substance be the same, or very near a-kin? _B._ The most of them, if not all, that have written on this subject, when they call the loadstone a terrella, seem to think as you do. But I, except I could find proof for it, will not affirm it. For the earth attracteth all kind of bodies but air, and the loadstone none but iron. The earth is a star, and it were too bold to pronounce any sentence of its substance, especially of the planets, that are so lapt up in their several coats, as that they cannot work on our eyes, or any organ of our other senses. _A._ I come therefore now to the business of the day. Seeing all generation, augmentation, and alteration is local motion, how can a body not transparent be made transparent? _B._ I think it can never be done by the art of man. For as I said of hard and heavy bodies in the creation, so I think of diaphanous, that the very same individual body which was not transparent then, shall never be made transparent by human art. _A._ Do not you see that every day men make glass, and other diaphanous bodies not much inferior in beauty to the fairest gems? _B._ It is one thing to make one transparent of many by mixture, and another to make transparent of not transparent. Any very hard stone, if it be beaten into small sands, such as is used for hour-glasses, every one of those sands, if you look upon it with a microscope, you will find to be transparent; and the harder and whiter a stone is, so much the more transparent, as I have seen in the stone of which are made millstones, which stone is here called greet. And I doubt not but the sands of white marble must be more transparent. But there are no sands so transparent that they have not a scurf upon them, as hard, perhaps, as the stone itself; which they whose profession it is to make glass, have the art to scour and wash away. And therefore I think it no great wonder to bring those sands into one lump, though I know not how they do it. _A._ I know they do it with lye made with a salt extracted from the ashes of an herb, of which salt they make a strong lye, and mingle it with the sand, and then bake it. _B._ Like enough. But still it is a compound of two transparent bodies, whereof one is the natural stone, the other is the mortar. This therefore doth not prove, that one and the same body of not transparent can be made transparent. _A._ Since they can make one transparent body of many, why do they not of a great many small sparks of natural diamond compound one great one? It would bear the charges of all the materials, and beside, enrich them.