The Pneumatics

is interspersed between the particles of sand, is similar to the vacuums contained within the air. Wherefore, by the application of some force, it happens that the air is condensed and settles into the spaces of the vacuums, the bodies being compressed among themselves contrary to nature; but when the pressure is released, it is restored again to the same order on account of the natural tension of the bodies, just as in shavings of horn and in dry sponges, which, if they are released after being compressed, return again to the same place and assume the same bulk. Similarly, if by some force the particles of air are drawn away from one another, and a vacuum space larger than nature allows is created, they run back toward one another again. For through a vacuum, a swift motion of bodies happens to occur, with nothing obstructing or repelling them, until the bodies are joined to one another. If therefore anyone, taking a very light vessel with a narrow mouth and applying it to his mouth, should suck out the air and let go, the vessel will immediately be suspended from his lips, the vacuum drawing the flesh in so that the emptied space may be filled. Thus from these things it becomes clear that the space which was in the vessel was entirely a vacuum. But this is also manifest for another reason. Eggs...