The natural history of the metals seems to have had a considerable share in the mythological mysteries of heathenism *. But leaving these fanciful doctrines of men, who gave the honour of God's works to their idols, we may go on from the metals to the gems, which are of an higher order, and a more refined nature. Here the glory of the terrestrial approaches very near to the glory of the celestial bodies; especially in the diamond, the prince of precious stones; which vies in purity and brightness with the matter of the heavens, and appears like embodied light; insomuch that, if the fluid of life could be fixed into an ice, as the fluid of water is, we may imagine that something like the diamond would be produced. It is remarkable, that the brightest matter of the earth is united

*Copper had its name from the Island of Cyprus, where the use of brass was said to have been first invented; (In Cypro, ubi prima fuit æris inventio. Plin. Lib. 34, cap. 2.) and hence we may account for the mystical dedication of that Island to Venus, the Cyprian goddess, (Diva potens Cypri. Hor.) who agrees in name with a planet in the heavens, and with the ore of Copper in the earth. On this plan, it is very probable that the fable of Jupiter's burial in the island of Crete might, at the bottom, be nothing but a mythological mode of signifying to those who were in the secret, that tin was found under ground in that island.

with the richest, for the formation of a precious stone; the various sorts which receive their colour from some metal; as the ruby from gold; the emerald from copper; whence emeralds were commonly found in the copper mines of Cyprus *. When the metals are united to a chrystalline, or pellucid basis, they form a gem; but, if to an opaque earthy mat ter, they form the high-coloured earths of the painters, which all derive their beauty from some metallic mixture. It is further remarkable, that the chrystalline matter, and the metal which gives it colour, are united in nature by the mediation of water; whereas, if we attempt to unite them by art, in the artifi cial gems, we are obliged to have recourse to the violence of fire, to diffuse the colouring parts through the chrystal. This, and some other like instances of the difference between the chemistry of art and the chemistry of nature, should make us cautious of pronouncing too hastily concerning subterraneous productions, lest we take that for the effect of fire, which was, in reality, the effect of

water.

Instead of naming the several minerals which are dug out of the earth, I shall rather

* Theophrastus.

direct your attention to two which are of more consequence than the rest: these are salt and sulphur. Salt preserves from putrefaction; and, being soluble in water, it keeps the sea sweet and wholesome. Where the heats are greater, the sea has more salt; be-cause there is more danger of putrefaction; which teaches us, that the sea was not salted by accident, but by design*. As the doctrine of truth in the Gospel saves the world from moral corruption, so doth salt preserve it from natural corruption; whence the one is used as a figure of the other. Ye are the salt of the earth, said Christ to his preachers: without you the world would be as putrid as flesh is found to be without the use of salt.

The other mineral substance is sulphur; of universal effect, as the cement of nature for uniting the parts of metals into masses, or mineralizing them, and giving them many of their properties. It is also the grand combustible of the world; which, as it descended

The late Dr. Halley, supposing that the sea grew salt by accident, in tract of time, from the waters washing away some salt from the land, proposed a new method for finding the age of the world, from the saltness of the sea. See Phys. Disq. where some farther observations are made on this subject.

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from the heavens in rain for the destruction of Sodom, so is now the chief cause of those dreadful commotions which happen in the earth. When iron and sulphur and water meet together, a fermentation ensues, which, if strong enough, breaks out into actual fire and flame. It hath pleased God, for wise ends, to lodge these different principles near to each other, in many places, that their mixture may present to our sight one of the most tremendous appearances in nature. When the sun shines upon the calmness of the ocean, we understand that God is benevolent as well as great; and, when the volcano rages, we are to learn that he is just and terrible in his wrath and vengeance. When the law was given on mount Sinai, the whole mount trembled, and burned with fire, and there were thunders and lightnings, and a thick cloud upon it. Here were all the appearances of a volcano; and, as this manifestation of God at Sinai was intended to fill the hearts of the people with the fear of God, by shewing them how terrible he is in his judgment against those who break his law; so every burning mountain, at this day in the world, should inspire the same religious fear; and, I believe, generally does, to those who are spec

tators

tators of it; declaring to the world, that God is the avenger of sin; and that the fires of nature, which are now but partial, and under the restraint of mercy and forbearance, shall at length break out to the burning of the earth, and of all things therein. When the flood came upon the world, the fountains of the great deep were opened; the waters of the air were added to the waters of the earth, and all united their forces to execute the divine sentence: so at the last visitation of this world, all the fountains of fire shall be opened: the burning mountains of the earth shall send forth all their hidden stores, while new ones shall be opened in all places; and the fires of the sky shall co-operate with the fires of the earth. Modern discoveries have taught us, that the sea, the earth, the air, the clouds, are replete with a subtile and penetrating matter, which, while at rest, gives us no disturbance; but, when excited to action, turns into a consuming fire, which no substance can exclude, no force can resist: so that the elements, which are to melt with fervent heat, want no accidental matter to inflame them: since all things may be burnt up by that matter which now resides within them, and is only waiting for the word from its Creator.

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