clothes only by his breath? Or from the hangings of a chamber wherein a man hath died? It is impossible. Therefore whatsoever killing thing is in the clothes or hangings, it must rise and go into his mouth or nostrils before it can do him hurt. It must therefore be a fly, whereof great numbers get into the blood, and there feeding and breeding worms, obstruct the circulation of blood, and kill the man. _A._ I would we knew the palate of those little animals; we might perhaps find some medicine to fright them from mingling with our breath. But what is that which kills men that lie asleep too near a charcoal-fire? Is it another kind of fly? Or is charcoal venomous? _B._ It is neither fly nor venom, but the effect of a flameless glowing fire, which dissipates those atoms that maintain the circulation of the blood; so that for want of it, by degrees they faint, and being asleep cannot remove, but in short time, there sleeping die; as is evident by this, that being brought into the open air, without other help, they recover. _A._ It is very likely. The next thing I would be informed of, is the nature of gravity. But for that, if you please, we will take another day. ========== CHAPTER VIII. OF GRAVITY AND GRAVITATION. _B._ What books are those? _A._ Two books written by two learned men concerning gravity. I brought them with me, because they furnish me with some material questions about that doctrine; though of the nature of gravity, I find no more in either of them than this, that gravity is an intrinsical quality, by which a body so qualified descendeth perpendicularly towards the superficies of the earth. _B._ Did neither of them consider that descending is local motion; that they might have called it an intrinsical motion rather than an intrinsical quality? _A._ Yes. But not how motion should be intrinsical to the special individual body moved. For how should they, when you are the first that ever sought the differences of qualities in local motion, except your authority in philosophy were greater with them than it is? For it is hard for a man to conceive, except he see it, how there should be motion within a body, otherwise than as it is in living creatures. _B._ But it may be they never sought, or despaired of finding what natural motion could make any inanimate thing tend one way rather than another. _A._ So it seems. But the first of them inquires no farther than, why so much water, being a heavy body, as lies perpendicularly on a fish’s back in the bottom of the sea, should not kill it. The other, whereof the author is Dr. Wallis, treateth universally of gravity. _B._ Well; but what are the questions which from these books you intend to ask me? _A._ The author of the first book tells me, that water and other fluids are bodies continued, and act, as to gravity, as a piece of ice would do of the same figure and quantity. Is that true?