The process of making the sword reflects the delicate control of carbon and of heat treatment by which a steel object is made to fit its function perfectly. Even the steel billet is not simple, because a sword must combine two different and incompatible properties of materials. It must be flexible, and yet it must be hard. Those are not properties which can be built into the same material unless it consists of layers. In order to achieve that, the steel billet is cut, and then doubled over again and again so as to make a multitude of inner surfaces. The sword that Getsu makes requires him to double the billet fifteen times. This means that the number of layers of steel will be 215, which is well over thirty thousand layers. Each layer must be bound to the next, which has a different property. It is as if he were trying to combine the flexibility of rubber with the hardness of glass. And the sword, essentially, is an immense sandwich of these two properties.
At the last stage, the sword is prepared by being covered with clay to different thicknesses, so that when it is heated and plunged into water it will cool at different rates. The temperature of the steel for this final moment has to be judged precisely, and in a civilisation in which that is not done by measurement, ‘it is the practice to watch the sword being heated until it glows to the colour of the morning sun’. In fairness to the swordmaker, I ought to say that such colour cues were also traditional in steelmaking in Europe: as late as the eighteenth century, the right stage at which to temper steel was when it glowed straw-yellow, or purple, or blue, according to the different use for which it was intended.
The climax, not so much of drama as of chemistry, is the quenching, which hardens the sword and fixes the different properties within it. Different crystal shapes and sizes are produced by the different rates of cooling: large, smooth crystals at the flexible core of the sword, and small jagged crystals at the cutting edge. The two properties of rubber and glass are finally fused in the finished sword. They reveal themselves in its surface appearance – a sheen of shot-silk by which the Japanese set high store. But the test of the sword, the test of a technical practice, the test of a scientific theory, is ‘Does it work?’ Can it cut the human body in the formal ways that ritual lays down? The traditional cuts are mapped as carefully as the cuts of beef on a diagram in a cookery book: ‘Cut number two – the O-jo-dan.’ The body is simulated by packed straw, nowadays. But in the past a new sword was tested more literally, by using it to execute a prisoner.
The sword is the weapon of the Samurai. By it they survived endless civil wars that divided Japan from the twelfth century on. Everything about them is fine metalwork: the flexible armour made of steel strips, the horse trappings, the stirrups. And yet the Samurai did not know how to make any of these things themselves. Like the horsemen in other cultures they lived by force, and depended even for their weapons on the skill of villagers whom they alternately protected and robbed. In the long run, the Samurai became a set of paid mercenaries who sold their services for gold.
Our understanding of how the material world is put together from its elements derives from two sources. One, that I have traced, is the development of techniques for making and alloying useful metals. The other is alchemy, and it has a different character. It is small in scale, is not directed to daily uses, and contains a substantial body of speculative theory. For reasons which are oblique but not accidental, alchemy was much occupied with another metal, gold, which is virtually useless. Yet gold has so fascinated human societies that I should be perverse if I did not try to isolate the properties that gave it its symbolic power.
Gold is the universal prize in all countries, in all cultures, in all ages. A representative collection of gold artefacts reads like a chronicle of civilisations. Enamelled gold rosary, 16th century, English. Gold serpent brooch, 400 BC, Greek. Triple gold crown of Abuna, 17th century, Abyssinian. Gold snake bracelet, ancient Roman. Ritual vessels of Achaemenid gold, 6th century BC, Persian. Drinking bowl of Malik gold, 8th century BC, Persian. Bulls’ heads in gold … Ceremonial gold knife, Chimu, Pre-Inca, Peruvian, 9th century …
Sculpted gold salt-cellar, Benvenuto Cellini, 16th-century figures, made for King Francis I. Cellini recalled what his French patron said of it:
When I set this work before the king, he gasped in amazement and could not take his eyes off it. He cried in astonishment, ‘This is a hundred times more heavenly than I would ever have thought! What a marvel the man is!’
The Spaniards plundered Peru for its gold, which the Inca aristocracy had collected as we might collect stamps, with the touch of Midas. Gold for greed, gold for splendour, gold for adornment, gold for reverence, gold for power, sacrificial gold, life-giving gold, gold for tenderness, barbaric gold, voluptuous gold…
The Chinese put their finger on what made it irresistible. Ko Hung said, ‘Yellow gold, if melted a hundred times, will not be spoiled.’ In that phrase we become aware that gold has a physical quality that makes it singular; which can be tested or assayed in practice, and characterised in theory.
It is easy to see that the man who made a gold artefact was not just a technician, but an artist. But it is equally important, and not so easy to recognise, that the man who assayed gold was also more than a technician. To him gold was an element of science. Having a technique is useful but, like every skill, what brings it to life is its place in a general scheme of nature – a theory.
Men who tested and refined gold made visible a theory of nature: a theory in which gold was unique, and yet might be made from other elements. That is why so much of antiquity spent its time and ingenuity in devising tests for pure gold. Francis Bacon at the opening of the seventeenth century put the issue squarely.
Gold hath these natures – greatness of weight, closeness of parts, fixation, pliantness or softness, immunity from rust, colour or tincture of yellow. If a man can make a metal that hath all these properties, let men dispute whether it be gold or no.
Gold is the universal prize in all countries, in all cultures, in all ages.
Greek gold: Mask of an Achaean king, from a shaft grave in Mycenae, 16th century BC.
Persian gold: Gold dinar of Khusrau II – minted in Iran.
Peruvian gold: Mochica puma, stamped with a design of two-headed serpents.
African gold: Cast gold badge, worn by the Asantehene’s (king’s) ‘soulwasher’ as a badge of office, a disk decorated with concentric incised bands, with a pyramidal boss. Ghana, before 1874.
Modern gold: Central input receiver, Concorde Multi-plexing calculator.
Edinburgh, 20th century.
Among the several classical tests for gold, one in particular makes the diagnostic property most visible. This is a precise test by cupellation. A bone-ash vessel, or cupel, is heated in the furnace and brought up to a temperature much higher than pure gold requires. The gold, with its impurities or dross, is put in the vessel and melts. (Gold has quite a low melting point, just over 1000°C, almost the same as copper.) What happens now is that the dross leaves the gold and is absorbed into the walls of the vessel: so that all at once there is a visible separation between, as it were, the dross of this world and the hidden purity of the gold in the flame. The dream of the alchemists, to make synthetic gold, has in the end to be tested by the reality of the pearl of gold that survives the assay.
The ability of gold to resist what was called decay (what we would call chemical attack) was singular, and therefore both valuable and diagnostic. It also carried a powerful symbolism, which is explicit even in the earliest formulae. The first written reference we have to alchemy is just over two thousand years old, and comes from China. It tells how to make gold and to use it to prolong life. That is an extraordinary conjunction to us. To us gold is precious because it is scarce; but to the alchemists, all over the world, gold was precious because it was incorruptible. No acid or alkali known to those times would attack it. That indeed is how the emperor’s goldsmiths assayed or, as they would have said, parted it, by an acid treatment that was less laborious than cupellation.<
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When life was thought to be (and for most people was) solitary, poor, nasty, brutish, and short, to the alchemists gold represented the one eternal spark in the human body. Their search to make gold and to find the elixir of life are one and the same endeavour. Gold is the symbol of immortality – but I ought not to say symbol, because in the thought of the alchemists gold was the expression, the embodiment of incorruptibility, in the physical and in the living world together.
So when the alchemists tried to transmute base metals into gold, the transformation that they sought in the fire was from the corruptible to the incorruptible; they were trying to extract the quality of permanence from the everyday. And this was the same as the search for eternal youth: every medicine to fight old age contained gold, metallic gold, as an essential ingredient, and the alchemists urged their patrons to drink from gold cups to prolong life.
Alchemy is much more than a set of mechanical tricks or a vague belief in sympathetic magic. It is from the outset a theory of how the world is related to human life. In a time when there was no clear distinction between substance and process, element and action, the alchemical elements were also aspects of the human personality – just as the Greek elements were also the four humours which the human temperament combines. There lies therefore in their work a profound theory: one which derives in the first place of course from Greek ideas about earth, fire, air and water, but which by the Middle Ages had taken on a new and very important form.
To the alchemists then there was a sympathy between the microcosm of the human body and the macrocosm of nature. A volcano on a grand scale was like a boil; a tempest and rainstorm was like a fit of weeping. Under these superficial analogues lay the deeper concept, which is that the universe and the body are made of the same materials, or principles, or elements. To the alchemists there were two such principles. One was mercury, which stood for everything which is dense and permanent. The other was sulphur, which stood for everything that is inflammable and impermanent. All material bodies, including the human body, were made from these two principles and could be remade from them. For instance, the alchemists believed that all metals grow inside the earth from mercury and sulphur, the way the bones grow inside an embryo from the egg. And they really meant that analogy. It still remains in the symbolism of medicine now. We still use for the female the alchemical sign for copper, that is, what is soft: Venus. And we use for the male the alchemical sign for iron, that is, what is hard: Mars.
That seems a terribly childish theory today, a hodge-podge of fables and false comparisons. But our chemistry will seem childish five hundred years from now. Every theory is based on some analogy, and sooner or later the theory fails because the analogy turns out to be false. A theory in its day helps to solve the problems of the day. And the medical problems had been hamstrung until about 1500, by the belief of the ancients that all cures must come either from plants or from animals – a kind of vitalism which would not entertain the thought that body chemicals are like other chemicals, and which therefore confined medicine largely to herbal cures.
Now the alchemists freely introduced minerals into medicine: salt, for example, was a pivot in the turn-about, and a new theoretician of alchemy made it his third element. He also developed a very characteristic cure for a disease which raged round Europe in 1500 and had not been known before, the new scourge syphilis. To this day we do not know where syphilis came from. It may have been brought back by the sailors in Columbus’s ships; it may have spread from the east with the Mongol conquests; or it may simply not have been recognised before as a separate disease. The cure for it turned out to depend on the use of the most powerful alchemical metal, mercury. The man who made that cure work is a landmark in the change from the old alchemy to the new, on the way towards modern chemistry: iatrochemistry, biochemistry, the chemistry of life. He worked in Europe in the sixteenth century. The place was Basel in Switzerland. The year was 1527.
The universe and the body are made of the same materials or principles or elements.
Paracelsus’ figure of the furnace of the body with a scale for the study of urine in diagnosis of illness, from the ‘Aurora Thesaurusque philosophorum’, Basel, 1577.
Paracelsus’ figure of the three elements, earth, air and fire.
There is an instant in the ascent of man when he steps out of the shadowland of secret and anonymous knowledge into a new system of open and personal discovery. The man that I have chosen to symbolise it was christened Aureolus Philippus Theophrastus Bombastus von Hohenheim. Happily, he gave himself the somewhat more compact name of Paracelsus, to publicise his contempt for Celsus and other authors who had been dead more than a thousand years, yet whose medical texts were still current in the Middle Ages. In 1500 the works of classical authors were still thought to contain the inspired wisdom of a golden age, in medicine and science as well as in the arts.
Paracelsus was born near Zürich in 1493, and died at Salzburg in 1541 at the early age of forty-eight. He was a perpetual challenge to everything that was academic: for example, he was the first man to recognise an industrial disease. There are both grotesque and endearing episodes in the undaunted, lifelong battle Paracelsus fought with the oldest tradition of his time, the practice of medicine. His head was a perpetual fountain of theories, many of them contradictory, and most of them outrageous. He was a Rabelaisian, picaresque, wild character, drank with students, ran after women, travelled much over the Old World and, until recently, figured in the histories of science as a quack. But that he was not. He was a man of divided but profound genius.
The point is that Paracelsus was a character. We catch in him, perhaps for the first time, the transparent sense that a scientific discovery flows from a personality, and that discovery comes alive as we watch it being made by a person. Paracelsus was a practical man, who understood that the treatment of a patient depends on diagnosis (he was a brilliant diagnostician) and on direct application by the doctor himself. He broke with the tradition by which the physician was a learned academic who read out of a very old book, and the poor patient was in the hands of some assistant who did what he was told. ‘There can be no surgeon who is not also a physician,’ Paracelsus wrote. ‘Where the physician is not also a surgeon he is an idol that is nothing but a painted monkey.’
Such aphorisms did not endear Paracelsus to his rivals, but they did make him attractive to other independent minds in the age of the Reformation. That is how he came to be brought to Basel for the single year of triumph in his otherwise disastrous worldly career. In Basel in the year 1527 Johann Frobenius, the great Protestant and humanist printer, had a serious leg infection – the leg was about to be amputated – and in despair appealed to his friends in the new movement, who sent him Paracelsus. Paracelsus threw the academics out of the room, saved the leg, and effected a cure which echoed through Europe. Erasmus wrote to him saying: ‘You have brought back Frobenius, who is half my life, from the underworld’.
It is not accidental that new, iconoclastic ideas in medicine and chemical treatment come cheek by jowl, in time and in place, with the Reformation that Luther started in 1517. A focus of that historic time was Basel. Humanism had flourished there even before the Reformation. There was a university with a democratic tradition, so that, although its medical men looked askance at Paracelsus, the City Council could insist that he be allowed to teach. The Frobenius family was printing books, among them some by Erasmus, which spread the new outlook everywhere and in all fields.
A great change was blowing up in Europe, greater perhaps even than the religious and political upheaval that Martin Luther had set going. The symbolic year of destiny was just ahead, 1543. In that year, three books were published that changed the mind of Europe: the anatomical drawings of Andreas Vesalius; the first translation of the Greek mathematics and physics of Archimedes; and the book by Nicolaus Copernicus, The Revolution of the Heavenly Orbs, which put the sun at the centre of the heaven and created what is now called the Scientific Revolutio
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All that battle between past and future was summarised prophetically in 1527 in a single action outside the Winster at Basel. Paracelsus publicly threw into the traditional student bonfire an ancient medical textbook by Avicenna, an Arab follower of Aristotle.
There is something symbolic about that midsummer bonfire which I will try to conjure into the present. Fire is the alchemist’s element by which man is able to cut deeply into the structure of matter. Then is fire itself a form of matter? If you believe that, you have to give it all sorts of impossible properties – such as, that it is lighter than nothing. Two hundred years after Paracelsus, as late as 1730, that is what chemists tried to do in the theory of phlogiston as a last embodiment of material fire. But there is no such substance as phlogiston, just as there is no such principle as the vital principle – because fire is not a material, any more than life is material. Fire is a process of transformation and change, by which material elements are rejoined into new combinations. The nature of chemical processes was only understood when fire itself came to be understood as a process.
That gesture of Paracelsus had said, ‘Science cannot look back to the past. There never was a Golden Age.’ And from the time of Paracelsus it took another two hundred and fifty years to discover the new element, oxygen, which at last explained the nature of fire, and took chemistry forward out of the Middle Ages. The odd thing is that the man who made the discovery, Joseph Priestley, was not studying the nature of fire, but of another of the Greek elements, the invisible and omnipresent air.
The Ascent of Man Page 9