7.  Thus, in the eyes of God, the sea is good, because it makes the under current of moisture in the depths of the earth.  It is good again, because from all sides it receives the rivers without exceeding its limits.  It is good, because it is the origin and source of the waters in the air.  Warmed by the rays of the sun, it escapes in vapour, is attracted into the high regions of the air, and is there cooled on account of its rising high above the refraction of the rays from the ground, and, the shade of the clouds adding to this refrigeration, it is changed into rain and fattens the earth.  If people are incredulous, let them look at caldrons on the fire, which, though full of water, are often left empty because all the water is boiled and resolved into vapour.  Sailors, too, boil even sea water, collecting the vapour in sponges, to quench their thirst in pressing need.