Nay, the influence of the planets were extended to the bowels of the earth, where they were supposed to produce metals. From hence it appears that when superstition and folly are once on foot, there is no setting hounds to their progress. Gold, as a matter of course, must be the production of the sun, and the conformity in point of colour, brightness, and value, was a sensible proof of it. By the same mode of reasoning, the moon produced all the silver, to which it was related by colour; Mars, all the iron, which ought to be the favourite metal of the god of war. Venus presided over copper, which she might be well supposed to produce, since it was found in abundance in the isle of Cyprus, the supposed favourite residence of this goddess. In the same strain, the other planets presided over the other metals. The languid Saturn domineered over the lead mines, and Mercury, on account of his activity, had the superintendency of quicksilver; while it was the province of Jupiter to preside over tin, as this was the only metal left him, it would appear, a kind of "Hobson's choice." This will explain the manner in which the metals obtained the names of the planets; and from this opinion, that each planet engendered its own peculiar metal, they at length formed an idea that, as one planet was more powerful than another, the metal produced by the weakest was converted into another by the predominating influence of a stronger orb. Lead, though really a metal, and as perfect in its kind as any of the rest, was considered only half a metal, which, in consequence of the languid influences of old Saturn, was left imperfect; and, therefore, under the auspices of Jupiter, it was converted into tin; under that of Venus, into copper: and at last into gold, under some particular aspects of the sun. From hence, at length, arose the extravagant opinion of the alchymists, who, with amazing sagacity, endeavoured to find out means for hastening these changes or transmutations, which, as they conceived, the planets performed too slowly. The world, however, became at length convinced that the art of the alchymist was as ineffectual as the influences of the planets, which, in a long succession of ages, had never been known to change a mine of lead to that of tin or any other metal.[69] The first author we are acquainted with who talks of making gold by the transmutation of one metal, by means of an alcahest[70] into another, is Zozimus the Pomopolite, who lived about the commencement of the fifth century, and who has a treatise express upon it, called, "The divine art of making gold and silver," in manuscript, and is, as formerly, in the library of the King of France.