The Pneumatics

...said body by the fluid occupying the same place. But indeed, that there are vacuities may also be perceived from these facts. For if vacuities did not exist, light could not pass through water, nor air, nor any other body, nor could heat or any other corporeal influence. For how would solar rays penetrate through water to the bottom of a vessel? For if water had no pores, but the rays cleaved the water by force, it would happen that full vessels would overflow, which we do not see occur. Moreover, if they cleaved the water by force, some of the rays would not be refracted to a higher place, while others fell downward. But as it is, those which encounter particles of water are refracted toward the upper region; whereas those which fall into the vacuities of the water, encountering few particles, penetrate to the bottom of the vessel. Furthermore, it is evident from these things that vacuities exist in water. For wine poured into water is seen to permeate through the entire space of the water by a certain diffusion; which would not happen unless vacuities were present in the water. One light also is carried through another. For when one lights several lamps, all things are made more