Because this corrosive is sharp, whenever it meets an earth of any kind it attacks it, always dissolving the most readily soluble portion first, little by little, until the vapours continually rising after it have corroded and dissolved much earth. When the corrosive, as a volatile sour salt-spirit or spirit of salt, attacks earth, it eats itself to death and becomes corporeal, vitriolic, or aluminous upon that earth, according to its nature. Conversely, the earth becomes subtle and the spirit coagulates. What earth the corrosive has not completely dissolved it has partly subtilized and prepared, making it dirty and greasy. Chymists call this dirty or greasy material a metallic Gur, or the first matter of metals, but wrongly: it is the first proximate matter of sulphur and arsenic. When arsenic becomes a marcasite, that is the first proximate metallic matter. Metals come immediately from marcasite, not from this Gur, which is only the remote matter of metals. The following corrosive vapours make this Gur or dirty material ever subtler and dissolve it further. The subtler it becomes, the more corrosive it fixes within itself, making it sulphurous and arsenical. This arsenic matures increasingly into a marcasite and only then into metal. Such is the progress of metals, which we shall make continually clearer.

When vapours rise into the clefts of rocks, condensation and the continual, increasing succession of more vapours make them into water. This water contains spirit of salt and nitre mixed within it. Every chymist knows that this spirit is corrosive, but here in the centre it is surrounded and diluted by much phlegm and water. Through their sharpness these spirits attach themselves to stones and earths, corrode and dissolve them, and make them subtle, swollen, pasty, greasy, and dirty: a moist Gur lying between stones and earths like meat larded with fat. Often the swelling makes it press right out and cling to the walls, as can be seen in every adit and mine. As the rising vapours and saline spirits dissolve and subtilize this dissolved earth further, it swells increasingly; by bulging upward it squeezes and expels the remaining moisture, which runs back to the centre or into other corners and holes in the earth. This swollen Gur now has no rest: the constantly rising and following vapours attack it more and more, cling to it, and fix and coagulate themselves upon the earth. The more corrosive vapours follow, the more fiery and sulphurous the earth becomes; the more sulphurous, the higher it swells; the more it swells, the more moisture it expels, growing steadily drier.

The drier it becomes, the more it loses its sulphurous character and combustibility, thereby acquiring the name of mercury—or, more properly, arsenic—which has arisen from the sulphurous acid. It no longer burns, though it is still volatile. The central heat between the stones increasingly binds, fixes, and coagulates this volatility until it becomes a marcasite. If digestion or the earth’s central heat is strong, the marcasite is fixed into a metal; if weak, it remains arrested as a marcasite, arsenical fumes, sulphur-pyrites, or vitriol-pyrites. The lover of the art should know that when nature has progressed far enough to make sulphur or arsenic, it has already filled the clefts and channels, dissolving and swelling so much earth that the clefts are packed full. Then the material admits no more vapours or moisture and is no longer undergoing dissolution. Drying, fixation, and coagulation now begin and proceed toward metallicity or permanence. This filling of earthly cavities and clefts seems to me exactly like honeybees filling their cells, little by little, with honey until they are packed full, and then closing them for storage.

Nature likewise sends one vapour after another, dissolving and swelling more and more earth. This earth is full of acid and is increasingly filled, until acid and earth are so mixed that, in relation to their first matter, one can no longer properly recognize what they were before. From acid and earth a third thing has arisen, entirely different from the first. This generation is like animal and vegetable generation, except that it intends to make more fixed, harder, stony subjects; it works in the same order. From moist, soft vapours it first makes soft things, gradually bringing them further and hardening them even into stone, just as a tender, soft, juicy young oak shoot or tree grows harder and harder into wood as hard as stone. Mineral creatures differ as follows. First, according to whether they receive much or little corrosive. With much, they become increasingly fusible; with little, they become and remain infusible. If the spirits receive a pure, subtle earth or stone, the more subtly they can work it, the nobler a metal they make. Conversely, the coarser the earth the corroding spirits receive and the less they work it—that is, make it subtler and nobler through dissolution—the coarser the metal. Again, the poorer the digestion and central heat, the less they are dried, coagulated, and fixed; they remain arrested, producing vitriol-pyrites and sulphurous, arsenical, antimonial, bismuthic, and similar ores. Strong digestion, by contrast, also makes lasting metallic ores.

Again, if digestion and central heat are uneven and too strong at first, the earth is dissolved, yet does not become volatile but immediately fixed and coagulated, advancing farther toward metallicity. Chymists call such things fixed embryonic sulphurs: bole, bloodstone, emery, lodestone, tutia, calamine, and so forth. If digestion is weak from the beginning, so that the earth and its cavities are soon filled and no more vapours can enter, the vapours settle elsewhere and the work begun remains arrested. Since it receives no stronger degree of central fire, it remains as it began, volatile and open, like vitriol-pyrites, sulphur-pyrites, and the others mentioned above. But when nature maintains an even degree through the four seasons or parts of the year, the tempered corrosives help it make noble metals, such as gold, silver, tin, and copper. Let the practitioner apply this for himself to the variable differences within the single human race. As the saying goes, many heads, many minds: though all of us are human, we are not alike, especially in our dispositions. In this one race everyone sees God’s greatest wonder: he created so many millions of people and their ideas, and among millions and millions there are scarcely two alike in even one, two, or three respects, much less in the complete bodily machine.

As nature makes great differences within that race, so she does within the mineral race. One vitriol, sulphur, arsenic, marcasite, or metal is not like another. Consider the difference within gold alone: it occurs in different degrees of colour according as nature has disposed it purely or impurely. One silver is finer than another; likewise one copper, iron, tin, lead, or mercury is finer than another. So also with the inferior minerals. Earths and stones are the mother and foundation, or vessel, of minerals, in which the things dug from the earth are made. Vapour or spirit of salt is their food and nourishment. Vitriol, or vitriolic Gur, is the root; sulphur or arsenic the stalk; marcasite the flower or blossom; metal the seed and complete birth and offspring. That vitriol first arises, before sulphur and arsenic, can be proved from Gur. Leach, filter, and coagulate it, and you find a vitriolic salt according to the kind of earth it dissolved. I call it vitriol not because it is ordinary green vitriol such as is bought from dealers, but because it has a vitriolic or aluminous taste.

That sulphur or arsenic comes next can be seen in anatomy. In white metals such as lead, tin, and silver, yellow burning sulphur is seldom found or found only in small amounts, but white arsenic and aluminous vitriol or alum more abundantly. When driven by fire, acid or sour vapours come first. Flowers of sulphur follow; then arsenic, then volatile marcasite. The fixed part flows into a regulus and slag. Anatomy also shows that marcasite is made from arsenic: antimony and bismuth, when brought into flowers, are wholly arsenical and volatile, possessing its entire nature and quality. That metal is made from marcasites through long fixation is shown by almost every marcasite yielding a grain of perfect or imperfect metal in the assay. The lover of the art thus sees how splendidly nature proceeds through middle degrees, rather than from one extreme to another. It proceeds from vapour, volatile according to its kind, toward an increasingly fixed nature; for that vapour is fixed in comparison with vegetable and animal vapour. Many authors have written that vitriol, the Gur, is the first matter of metal; some have added that antimony is the root and mother of metals. But they have made no distinction, so that error and confusion have arisen from which the lover of the art cannot find his way to correction.

Not every chymist descends into mines; even if he does, scarcely one in a thousand understands such things. He looks at mountains, walls, ore, and stones, seeing that something is black or white and is this or that metal. He cannot penetrate farther, as mere inspection indeed makes impossible. But if he breaks off a piece of ore, brings it into the fire, and drives up one portion after another, he can examine those parts further and judge what they are and contain. Generally, if a liquid accompanies them, it is acidic, vitriolic, or sulphurous; if there are flowers, they are usually sulphur and arsenic. Sulphur is recognized by its burning and stench. Of the arsenic, give something to a dog: if it vomits, it is arsenical; then quickly give it a piece of butter stirred together with mithridate. Marcasite is recognized when it has not risen so high, but a volatile part has risen above the more fixed, as cinnabar or mercury rises above the dregs. Melt them together and you obtain a brittle reguline mass: that is the marcasite.