That metals consisted partly of water was obvious from the fact that, when you heated them up, they became fluids. But some other substance must be combined with water in order to create a metal. The missing ingredient was supplied by invisible rays from the planets, which penetrated the ground and combined with the water that was there in the earth. The rays from that dimmest and most sluggish of planets, Saturn, created the basest of all metals, lead. Jupiter was responsible for tin and Mars for iron. Venus did copper, the moon silver, Mercury, obviously, accounted for mercury, and the Sun made gold. This was why the gold-hungry Spaniards, in their explorations and conquests, had never strayed far from the Equator, for that was where the Sun beat down most directly, and produced the richest deposits of its precious Element.