_A._ What I want of experiments you may supply out of your own store, or such natural history as you know to be true; though I can be well content with the knowledge of the causes of those things which everybody sees commonly produced. Let us therefore now enquire the cause of some effect particular. _B._ We will begin with that which is the most universal, the universe; and enquire in the first place, if any place be absolutely empty, that is to say in the language of philosophers, whether there be any vacuum in nature? ========== CHAPTER III. OF VACUUM. _A._ It is hard to suppose, and harder to believe, that the infinite and omnipotent Creator of all things should make a work so vast as is the world we see, and not leave a few little spaces with nothing at all in them; which put altogether in respect of the whole creation, would be insensible. _B._ Why say you that? Do you think any argument can be drawn from it to prove there is vacuum? _A._ Why not? For in so great an agitation of natural bodies, may not some small parts of them be cast out, and leave the places empty from whence they were thrown? _B._ Because He that created them is not a fancy, but the most real substance that is; who being infinite, there can be no place empty where He is, nor full where He is not. _A._ It is hard to answer this argument, because I do not remember that there is any argument for the maintenance of vacuum in the writings of divines: therefore I will quit that argument, and come to another. If you take a glass vial with a narrow neck, and having sucked it, dip it presently at the neck into a basin of water, you shall manifestly see the water rise into the vial. Is not this a certain sign that you had sucked out some of the air, and consequently that some part of the vial was left empty? _B._ No; for when I am about to suck, and have air in my mouth, contracting my checks I drive the same against the air in the glass, and thereby against every part of the sides of the hard glass. And this gives to the air within an endeavour outward, by which, if it be presently dipped into the water, it will penetrate and enter into it. For air if it be pressed will enter into any fluid, much more into water. Therefore there shall rise into the vial so much water as there was air forced into the basin. _A._ This I confess is possible, and not improbable. _B._ If sucking would make vacuum, what would become of those women that are nurses? Should they not be in a very few days exhausted, were it not that either the air which is in the child’s mouth penetrateth the milk as it descends, and passeth through it, or the breast is contracted? _A._ From what experiment can you evidently infer that there is no vacuum?