By making use of these the deity put together this world, sensible to touch through the particles of Earth, and to sight through those of Fire; which two are the extremes. Through the particles of Air and Water he has conjoined the world by the strongest chain, namely, proportion; which restrains not only itself but all its subjects. Now if the conjoined object is a plane surface, one middle term is sufficient; but if a solid, there will be need of two. With two middle terms, therefore, he combined two extremes; so that as Fire is to Air, Air might be to Water, and Water to Earth; and by alternation, as Fire is to Water, Air might be to Earth; and by inversion as Earth is to Water, Water might be to Air, and Air to Fire; and by alternation, as Earth is to Air, so Water might be to Fire. Now since all are equal in power, their ratios are in a state of equality. This world is then one, through the bond of the deity, made according to proportion.
How each of these substances possesses many forms; Fire, those of Flame, and Burning and Luminousness, through the inequality of the triangles in each of them. In the same manner, Air is partly clear and dry, and partly turbid and foggy; and Water partly flowing and partly congealed, according as it is Snow, Hoar-frost, Hail or Ice; and that which is Moist, is in one respect flowing as honey and oil; but in another is compact, as pitch and wax; and of compact-forms there are some fusible, as gold, silver, copper, tin, lead and steel; and some friable, as sulphur, pitch, nitre, salt, alum, and similar metals.