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As for those who say they have been sensible of the cold of air and water, but never felt the earth so cold, they consider only the surface of the earth, which is a mixture of air, water, sun, and heat. They are no better than people who deny the aether to be naturally and primitively hot, but believe it to be either scalding water or red hot iron, because they feel and handle the one, but are not sensible of the pure and celestial fire. In like manner, neither do they see the earth which lies concealed at the bottom, though that be what is chiefly to be taken for the earth, separated from all other things. We may see some token of this lower earth in these rocks here about us, which from their depths send forth a cold vapor so sharp and vehement that it is hard to be endured. They also that desire cool drink throw small flint stones into water. For it becomes denser and quicker to the taste, through the cold which is carried upward fresh and unmixed from the stones.
