Seven Elements That Have Changed the World (19 page)

The Spanish saying ‘vale un Potosí’, as rich as Potosí, became an expression of the highest praise.
⁶
Potosí became a global symbol of wealth, leading the Holy Roman Emperor to grant Potosí the title of Imperial City, presenting a shield with an inscription, translated as: I am rich Potosí, treasure of the world, king of the mountains, envy of kings.’
⁷

But underneath Potosí’s glittering display of wealth lay a darker reality, the effective slavery of millions of Indians. Inca society was based around a system of coerced labour so that the Indians had an ‘ingrained acquiescence to the notion of tribute.’
⁸
Effectively, the conquistadors exploited this social structure which enslaved the native workers. It was kept in place for 250 years. Over 10,000 men were taken each year from their homes in the Bolivian and Peruvian highlands.
⁹
The Spanish considered them ‘animals without masters’, sometimes making them work up to half a kilometre underground for twenty-three weeks a year without rest, day and night.
¹⁰
Whipping and beating was common practice and this often killed the exhausted miners. Cerro de Potosí came to be known as ‘the mountain that eats men’, a name it retains among miners today who still risk their
lives extracting tin from the ancient mine shafts.’
¹¹
A llama is still sacrificed every year at the mouth of the mine in the hope of appeasing the devil that lives inside the mountain. But today the city of Potosí, like the mountain, is a shell of its former self. High in the Andean mountains, with a climate unsuitable for growing crops and disconnected from major South American cities, only the silver mines sustained the lavish city life in the sixteenth and seventeenth centuries. When the precious metal was gone, the people, the gambling halls and the grand fiestas followed. Unlike in California after its gold rush, there were few opportunities for the local economy to diversify. The mountain, riddled with tunnels, has long since been ransacked, the surface a slag heap, coated in worthless, discarded rock that gives Cerro de Potosí a reddish hue.

Along with the gold of Atahualpa and of the Muisca, much of Potosí’s silver was shipped to Europe by merchants or as tribute to the King of Spain. But as one seventeenth-century observer remarked: ‘What is carried to Spain from Peru is not silver, but the blood and sweat of the Indians.’
¹²

Silver from Potosí flowed through the trading centres of Genoa, Florence and Venice. Production at Europe’s own silver mines was also booming. In the late fifteenth and early sixteenth century, new mines were discovered in Saxony and the Tyrol and new mining technologies were making many old mines profitable once again.
¹³
In 1527, during this mining boom, Georgius Agricola became the town doctor in the small Bohemian city of Joachimsthal, close to where he was born in Saxony. Joachimsthal, today Jáchymov in the Czech Republic, sits on the slopes of the Ore Mountains, the centre of Europe’s mining industry. There he saw how the science and technology of mining and processing ores was transforming the world around him. The town had only been founded eleven years before Agricola’s arrival, but within that time had grown from a population of 1,000 to over 14,000, as a result of the prodigious output of the city’s silver mines and the ‘thaler’ coins minted from it.
¹⁴
Much of Agricola’s time was spent studying and visiting the mines and smelters on the surrounding hillside. Around 1530 he resigned his
position as town doctor and spent the next few years travelling. His subsequent studies came to form part of his work on mining,
De re metallica
, whose authority on the subject would not be surpassed until the Age of Enlightenment.

In this work, Agricola not only explains, in meticulous detail, how to find, extract and process valuable ores but also becomes a lobbyist for the miner and his art. To Agricola, the advantages of mining were all too clear, yielding the ingredients for medicines and paints, and metals for coins. ‘No mortal man,’ writes Agricola, ‘ever tilled a field without [metal] implements.’
¹⁵
To those who questioned the relevance of mining, who believed that miners have ‘the most bitter and miserable lives’, Agricola asked: ‘How much does the profit from gold or silver mines exceed that from agriculture? … Those who condemn the mining industry say that it is not in the least stable, and they glorify agriculture beyond measure. But I do not see how they can say this with truth, for the silver-mines … remain still unexhausted after 400 years.’
¹⁶
But, he says, mining is only profitable ‘to those who give it care and attention’.
¹⁷
The miner must understand a great many arts and sciences if he is to be successful.
¹⁸
He must know how to ensure the health of his workmen and how he may ‘claim his own rights’ through the law. It almost feels as if Agricola is describing the capabilities of today’s mining companies.

Agricola recounts the discovery ‘by chance and accident’ in the twelfth century of a great silver vein by the River Sala near the town of Freiberg, fifty miles from Joachimsthal, under the control of the Margrave Otto of Meissen, more commonly known as Otto ‘the Rich’.
¹⁹
For much of the thirteenth century, Freiberg was the centre of European silver discoveries, with one mine taking over when the previous one became exhausted. But this stopped in the second half of the fourteenth century, when fewer and fewer new mines were discovered and the silver stopped flowing into Europe.
²⁰

Miners following a silver vein eventually reached thin black veins of pitchblende, which we know now as uranium ore, and which usually meant the end of that particular silver vein. The pitchblende at Joachimsthal was very rich in uranium and, much later, was used for the building of atomic bombs. Other mines would be abandoned because they contained
‘demons of ferocious aspect’, wrote Agricola, which must be ‘expelled and put to flight by prayer and fasting’.
²¹
We now interpret these demons as noxious and explosive gases. The art of mining has made great leaps since his time. We no longer use astronomy to judge the direction of veins, nor do we believe in demons and trolls. The four-kilometre-deep Tau Tona gold mining pit in South Africa and the complex chemistry of rare earth metal extraction are beyond Agricola’s wildest imaginings. However, his reverence for the wide benefits that mining can bring to society holds true today. Whether these benefits are realised depends on how we choose to extract and use minerals. Agricola understood that the elements are neither good nor bad: ‘For good men employ them for good, and to them they are useful. The wicked use them badly, and to them they are harmful.’
²²

The silver from Bohemia transformed European coinage. Otto the Rich and his successors opened dozens of mints in Germany, casting silver coins that flowed into England in exchange for wool and cloth. Silver coins were minted on an unprecedented scale. They were, for many purposes, more practical than gold ones. Their lower value enabled them to be used for smaller transactions among medieval Europe’s burgeoning merchant class. Silver coins even passed through the hands of peasants, perhaps for the first time since antiquity.

The Owls of Athens are thick and heavy silver coins stamped with the helmeted head of Athena on one side and her owl, the symbol of wisdom, on the reverse. First minted at the end of the sixth century
BC
in Athens, they soon spread far outside its walls. They were used as a tool of foreign trade and became a symbol of Athenian power. Other coins came and went; only the weight and form of the Owl remained constant for more than three centuries. And that consistency ensured that Athenian coins were accepted and trusted throughout the Mediterranean. Only the Venetian ducat of medieval Europe, which was minted for more than half a millennium, would rival the longevity and credibility of the Owl. The first Owls were minted just as Athens was starting to go through a period of
unprecedented political and economic growth with democracy firmly established.
²³
Athens’ prosperity depended on its control of the Aegean seas, its islands and coastal cities, and that was made possible by its formidable fleet. It also depended on silver, much of which came from the silver mined at Laurium, 65 kilometres south of the city. The mines helped Athens rise to become the pre-eminent civilisation of the Mediterranean. Xenophon wrote: ‘the Divine Bounty has bestowed upon us inexhaustible mines of silver, an advantage which we enjoy above all our neighbouring cities, who never yet could discover one vein of silver ore in all their dominions.’
²⁴
But in 413
BC,
Athens began to lose control of its silver when the Spartans captured a nearby town, creating a fortress from which to occupy the region.
²⁵
A general defected to the Spartans and told them how their occupation could cut Athens off from the silver mines of Laurium.
²⁶
The plan worked, the mines were closed and, in an act of desperation, the city melted down the gold objects on the Acropolis, including eight gold statues of Nike, the goddess of victory. In 404
BC,
following a prolonged siege, Athens surrendered to the Spartans. Thucydides described the chronic shortage of silver as a principal cause of Athens’ defeat. The silver mines had supported the rise of a great civilisation, but their absence hastened its fall.

Nike had been abandoned. From her, new gold coins were made with the same weight and form as the silver coins they replaced. But because of gold’s greater value, each coin was worth twelve times its silver counterpart. This high value made the coins of little use for local retail transactions and they were predominantly used to pay for shipments of goods from abroad. It was silver, not gold, that reigned supreme during Athens’ cultural, political and economic heyday. The importance of silver was evident in the historically low ratio between the value of gold and that of silver. In Athens, gold was worth twelve times the value of silver, very similar to a ratio of ten decreed by King Croesus in Lydia. For over three millennia it has fluctuated in the range of 9:1 and 16:1; in 2011, gold was worth at least fifty times as much as silver.

The relative values of silver and gold simply float, based on relative supply and demand. Local variations in the distribution of sources of gold and silver lead to local differences in the ratio of their values, but,
as international trade develops, these variations are gradually smoothed out. An ounce of silver was always worth much less than an ounce of gold. That was one of its historic attractions because it could be made into smaller ‘change’, low-value coins for everyday trade. To make this practical and to ensure that tradesmen knew where they stood, state treasuries or monetary authorities would need to fix, as opposed to let float, the ratio of value between gold and silver. That, time and time again, opened up opportunities for unintended arbitrage at the expense of the state. For example, as early as the Middle Ages, when silver was abundant in Europe, it was profitable to ship the bullion across the Mediterranean to northern Africa where it would be swapped for gold. Silver has always been more abundant than gold and, for state treasuries who wanted to ease the money supply, silver was the thing they used. That ‘unsound’ monetary practice could never be sustainable. Over time, gold became the preferred international standard of value, it became more in demand and its relative price strengthened.
²⁷
Silver became a shadow of its former self until, in the middle of the nineteenth century, it found a new role as the basis for photography.

In the hot New York summer of 1973, I spent weekend afternoons in Washington Square Park taking photographs. In the centre of the park an array of chess tables were always crowded with old men, faces staring intently at the black and white chequered boards. As I pressed my shutter release, light reflected from this city scene streamed in through the open aperture and on to the silver halide film. Where photons struck, atoms of pure silver formed, recording an image of history.
²⁸

The idea of permanently fixing images was first conceived by Thomas Wedgwood, the son of Josiah Wedgwood, the renowned English potter, at the end of the eighteenth century. Josiah had used a camera obscura, which projects an image of its surroundings on to a screen, to draw images more rapidly and accurately on to his pottery. Wedgwood wondered how he might be able to give these images permanence and set about experimenting with silver nitrate, whose light-sensitive properties
had been known since an accidental discovery by a German university professor in 1725. Johann Schulze was investigating the properties of a nitric acid and chalk solution (which also happened to contain some silver) at the University of Altdorf, near Nuremberg. He was working near a window and, since it was a sunny day, light streamed into the clear jar in which he had placed the solution. Suddenly he noticed that the part of the mixture facing the window had turned purple, while that facing inwards was still white. Perhaps, he thought, it was the heat of the sun that was causing a chemical reaction in the solution. He tried the experiment again, but this time kept the jar in the dark. Nothing happened. Schulze realised it must have been the action of the sunlight transforming the mixture and, after further investigation, concluded that silver was the vital element in this reaction.
²⁹
Wedgwood used this discovery. He coated sheets of paper with silver nitrate solution and then placed objects on top of them. By exposing the sheets to sunlight, he created silhouettes of the objects but sunlight would gradually blacken the remaining silver nitrate and the image would disappear.
³⁰
Frustrated and suffering from ill health, he stopped his experiments. The invention of photography, which created permanent images, would have to wait another thirty years.