What is arsenic but a corrosive? Does it not eat away and corrode all metals, sparing neither gold nor silver? Do we not clearly see that in some places subterranean vapours are so corrosive that they drive miners out of the pits unless they wish to suffocate? If there is no corrosive in the earth, why are some miners’ clothes eaten away as though steeped in aqua fortis when they merely lean against certain places? Consider and examine subterranean waters and concentrate a good quantity of them by distillation: the warm baths of sulphur, alum, and vitriol, and the sour springs. Are these not extended corrosives? Concentrate them, heat them a little, and put a slaughtered hen into them: will they not loosen and strip off not only feathers but skin and flesh, which fresh or even salt water upon and above the earth never does? One sees this even without preparation when a person bathes too much in such waters: they violently attack the constitution and skin, often making the person hideous and peeling the skin. Sour springs likewise cause this if too much is drunk. After the death of a patient who used a sour spring, his muscles were found quite loose, detached, and friable, as if he had been steeped like a fowl, and they could have been separated from the body without an anatomical knife.

Concentrate several measures of such waters: how little powerful substance they contain, amid a great quantity of water, yet what a powerful effect it produces! Chymists cannot understand how this corrosive can conceal itself, still less the squared-off, chattering Peripatetic Aristotle; no miner speaks of it, and no historian has written of it to date, or scarcely at all. The reasons, as I have said, are: first, the abundance of water; second, the earth, which takes the corrosive into itself and coagulates it; third, that no corrosive can ever be perceived as a vapour, though it can as water. The following trial bears witness. Take oil of vitriol or sulphur, or spirit or oil of salt, nitre, and so forth. Pour one pound into a tub or bucket of water and stir well. This can be given to a person to drink without harm, showing that the corrosive is not noticed. So it is within the earth. Again, put one or two pounds of chalk into such water and let it boil well together. Pour the water off the chalk and test the chalk: you will find it has become salty. This salt comes from the corrosive that the chalk has drawn in and fixed. Part remains in the water: evaporate and crystallize it, and you find a vitriol formed and fixed from the dissolved chalk. So it is in the earth.

Fourth: when a corrosive is surrounded by water and driven upward as vapour, it cannot be perceived, except sulphur alone, which is a pure concentrated corrosive. Take aqua fortis or aqua regia, spirit of vitriol or its oil, and so forth; put it in a little dish over the fire and let it evaporate in a room. It will make an enormous vapour and mist, so that one little quint will fill a whole room with nothing but vapour and mist. Anyone can breathe this vapour without noticing the least sharpness. Yet put only one or two liquid drops on a person’s tongue and see how he jumps, whether the fire does not penetrate him! The higher such a corrosive is driven into the air as vapour, the more it mixes with air and is sweetened and made chaotic by its volatile salt. From this the lover of the art should again observe carefully that circulation returns not only air but every dissolved thing to first matter or chaotic water: not only animal exhalations, but vegetable and mineral ones too, and whatever is resolved by any means into water or vapour—animals by fire, water, and earth, and plants by fire, water, and earth.

How many animals and plants are daily dissolved by water! Some are cooked for human food, releasing vapours as they cook; others are consumed by fire and used for cooking, while great smoke issues cloud-like through the chimney. Cooks burn no small number of animal bones in that fire and send them through the smoke-hole; butter and fat, too, are not too good for them when the fire will not burn. From what has been said it is now clear that nature can make no metal without a corrosive. If nature made metals with raw, corporeal saltwater and nitre-water—which might indeed be possible, since saltwater alters all readily soluble earths—where it otherwise had to work for a hundred years, here it would certainly have a thousand years’ work. For when salt is spiritual and resolved, it attacks twenty times more strongly than when merely dissolved in water.

Take a corrosive, or a salt made spiritual, and digest an earth with it in a small flask in a sand bath, dissolving it. Then take the corporeal salt from which that corrosive was made, put it in water so that it dissolves, pour it upon an equal quantity of the same earth, and set both to dissolve together. Examine them and see the difference. When both have dissolved, the corrosive will give a bitterish, astringent vitriol; the corporeal salt will give nothing of that quality. What then? Dissolve a metal with dry or wet corporeal salt into such a truly mineral vitriol, whether by fusion or through water in a liquid state: a great difference will appear. The corrosive will begin to attack immediately and make a vitriol, while the salt will deliberate long enough and never give a vitriol equal to the corrosive’s in virtue, power, and taste. If someone still doubts and says it is untrue that nature makes minerals through a corrosive, I tell him, first, to withhold his belief until many mistakes and wanderings compel him to it.

Second, I refer him to the more volatile and much weaker race of animals, in which sufficient sharpness is found to allow an inference to the mineral kingdom, from the lesser to the greater. If the human stomach had no sharpness attacking food, how could it accomplish such a marvellous, swift, rapid putrefaction? Give a person a readily soluble metal, such as copper or antimony: does the stomach’s menstruum not immediately attack and dissolve it? But because it is heterogeneous to him, it causes a convulsion and throws it out again by vomiting. Everyone sees that every dissolution requires sharpness. If human sharpness is great, it is greater in plants and greatest in minerals, which must have the strongest digestion because they must cook raw, fixed earth. Plants, by contrast, need a subtle earth, already putrefied long before and daily, for their being; humans and animals must digest and cook the softest, juiciest plants with their stomach and acid. This sharpness is called a dissolving corrosive acid, a corrosive menstruum—from corroding—because it attacks, crushes, grinds, dissolves, and makes the subject subtle and small.

Chymists themselves call the sharpest rectified spirit of wine and urine a corrosive, although in its diluted condition it is an excellent medicine for the lamp of life and a refreshment of all natural powers. Thus, although everyone receives animal and vegetable spirits in a diluted or extended condition, when concentrated and rectified from superfluous moisture they are extremely sharp and must be taken in the smallest dose. If there is such great sharpness in us and in other animals and plants, who should doubt it in minerals, which necessarily need three times more sharpness to dissolve raw earth? I have said that the acid or corrosive mineral menstruum—that is, the subterranean sour and salty vapours—dissolves earth, thereby making itself together with the earth into a greasy Gur, which is vitriolic or aluminous and acidic. The more this Gur is resolved, digested, fermented, coagulated, and fixed by the corrosive acid continually rising after it, or the chymical-salty vapours, or vaporous volatilized salt, the more sulphurous and arsenical it becomes. Simple water or phlegm cannot accomplish this—that is, dissolve such earth and make metal from it—without spiritual salt.

As acid accumulates in Gur and Gur in acid, the more acid it receives, the more sulphurous and fusible it becomes. This sulphur is increasingly digested and fixed, degree by degree, becoming arsenic; arsenic becomes marcasite, the proximate matter of metal, just as sulphur and volatile arsenic are the proximate matters of marcasite, and Gur or the vitriolic being is the proximate matter of sulphur and arsenic. When vitriol or Gur is overwhelmed with acid and dried, sulphur arises. This may be seen by repeatedly distilling aqua fortis or aqua regia from common vitriol through an alembic at the third degree in sand, so that the vitriol continually becomes drier. Throw it upon a glowing coal and sulphur will immediately be perceived. When sulphur and arsenic, together or separately—though sulphur is born first through the accumulation of vitriolic acid or the saline acid of salt—have been brought into marcasite, long digestion and maturation, or evaporation, coagulation, and fixation, make the marcasite into metal according to the strength of digestion and incidental properties. This gives in theory the beginning and end of mineral, metallic generation.

We shall now set down anatomical operations, as far as possible, to confirm our theory, although this has already been indicated sufficiently, here and elsewhere, to make it as plain as possible to a well-informed person. Since many faithful but simple people also venture into our art, I shall contribute the following. Take an ore as it comes from the mountain, before any operation by fire—for example lead, tin, iron, copper, gold, or silver ore. Wash one of these clean from its gangue on the washing apparatus, or leave the gangue with it; either will do. Powder it to the size of millet grains, not dust: dust would lie too fine and densely together and become more fixed than resolved, because the rising vapours would be stifled. Put this powder in a strong retort over an open fire, attach the receiver, and apply fire by degrees. You will see a little water rise first: this is the superfluous moisture. Strong mists follow, constituting the mineral corrosive; they settle in the receiver and resolve into corrosive water. Vapours then rise again, but less volatile than the first, for the more volatile always comes first and the more fixed parts follow. Little of these vapours reaches the receiver. Especially with a long retort neck, they settle toward its front, and each following portion farther back toward the retort’s belly, because the later portions can endure fire better.