Heronis Alexandrini spiritalium liber

vanishes. Wherefore it is mixed and itself becomes earth. But if anyone says that it is absorbed and not imbibed by the earth, but evaporates and is dried out by the heat of the sun or some other heat, he will be detected as saying what is false. For the same water poured into some vessel, whether glass or bronze, or consisting of other dense matter, and exposed to the sun for a long time, is not diminished, except in a very small particle of itself. Wherefore, water is also changed into an earthy substance. For slime and mud are changes of water into an earthy substance. A thinner substance is also changed into a thicker one; just as we see flame from extinguished lamps, when the oil fails, being carried upward a little and, as it were, pushed into its own place, departing. I speak, however, of the highest place, which is above the air, but overcome by the much intermediate air, it is no longer carried to its destined place, but, mixed and tangled with the bodies of the air, it is turned into air. It is proper to understand something similar regarding air. For when it exists in some vessel that is not large and is closed...