Periodic Tales

by Hugh Aldersey-Williams

  On Christmas Eve 1800, the two men bought up nearly 6,000 ounces of river-dredged platina from a disreputable vendor who had probably obtained it smuggled via the British West Indies from New Granada. The purchase cost them £795, a handsome sum, but the quantity was vast, and platinum was as yet far cheaper than gold. If they succeeded in converting this heap of grey crumbs into lustrous metal, they would be very rich men.

  Wollaston took the lead in this commercial project, dissolving the raw material a pound at a time in aqua regia, then reacting it with ammonium salts to form a precipitate which could be heated to release the precious metal. However, his ingots turned out brittle and were no use for further work. Tennant meanwhile examined the small amount of black residue that always remained behind when the native platinum was dissolved in aqua regia, quickly becoming convinced that it was not merely graphite as others had supposed, but metallic in nature. By extracting the black powder and carefully treating it with various powerful reagents, he was able to obtain new precipitates of different colours and a pungent oily liquid. These proved to be compounds of two new metals, which Tennant named iridium (after the Greek for rainbow because of the colours of its salts) and osmium (from the Greek for smell). Tennant was closely pursued in this work by French scientists, but had wisely taken the precaution of sharing his hunch that the residue was metallic with Sir Joseph Banks, the President of the Royal Society, thereby ensuring that he was rightfully acknowledged as the discoverer of both elements.

  Wollaston followed similar procedures in experiments with the platinum-rich liquor produced by the aqua regia. He too noticed an unexpected precipitate, which he soon satisfied himself contained yet another new metal. He thought to call it ceresium after the minor planet Ceres, which had been discovered a few months before, but then opted for the name palladium. However, rather than publish or communicate the news of his discovery informally as Tennant had done, Wollaston waited until he had amassed a significant quantity of the new metal–and then made his eccentric decision to advertise it for sale in small portions charged at five shillings, half a guinea and one guinea.

  When Chevenix communicated the results of his investigation, it put Wollaston in a quandary. He was now unable to claim the discovery that was his due without admitting his subterfuge. Instead, he issued another anonymous communiqué, this time in a chemical journal, offering a reward of £20 to the person who, before a jury of three chemists, could make twenty grains of palladium. Nobody seems to have risen to the challenge. Meanwhile, he quietly went on with his researches. His next discovery was to offer him a way out. Further experiments with the raw platina and aqua regia yielded new rose-coloured salts, indicative of another new element, which Wollaston named rhodium. This time, there would be no foolishness about the announcement. His friend Tennant had recently given his own paper, formally announcing his discovery of iridium and osmium. Wollaston followed his example and read out his paper on rhodium to the Royal Society in June 1804. He did not use the occasion to disclose the mystery of palladium, but a few months later, he wrote again to the journal where he had advertised his reward, explaining that it was he who had secretly discovered palladium and offered it for sale, putting forward as excuse for his behaviour that chemical anomalies observed at the time of the palladium discovery had prevented him from announcing it then, and that he had resolved these anomalies with the subsequent discovery of rhodium. This was not quite true, but it did enable Wollaston to save face.

  The new elements at last explained the brittleness of the platinum ingots. Armed with this knowledge, Wollaston pressed on with his manufacturing process and eventually obtained a valuable product. Over the next fifteen years, he built a tidy business constructing platinum boiling vessels for use in chemical factories and other specialist devices. Wollaston only revealed the details of the process a month before his death in 1828 when he knew he was suffering from a fatal illness.

  Over the years, Wollaston and his partner Tennant purchased some 47,000 ounces of native platina and produced 38,000 ounces of malleable platinum–about a bath full–as well as 300 ounces of palladium and 250 ounces of rhodium, enough to fill a pint glass with each metal. Some of the platinum was formed into crucibles for scientific experiments or rods for drawing into wire, but most of it went to gunsmiths, who used the metal to improve the contact points of flintlock pistols where it was cheaper and more effective than the gold they had been accustomed to using for the purpose. Wollaston and Tennant bought their platina at a typical price of two shillings for a thousand ounces, and sold pure platinum at sixteen shillings an ounce–a 6,000-fold increase! The secrecy that necessarily attended the perfection of this highly lucrative process simply appears to have warped Wollaston’s judgement when it came to the discovery of palladium.

  Wollaston’s career prospered nevertheless. His momentary lapse of scientific protocol was forgiven, and he won admiration for further discoveries in chemistry and optics as well as for his platinum process, from which he may have made a fortune of £30,000 or more, equivalent to quite a few million pounds today. Chevenix, disheartened by the episode, renounced science, married a French countess and turned to writing historical dramas.

  The Ochreous Stain

  Earthly power may arise from the possession of gold, but iron once radiated celestial power. Lumps of it fell from the sky–they still do. These iron meteorites, gifts of pure metal handed down from the heavens, held an instant sacred appeal. In some ancient beliefs, the sky itself was made of metal. Ilmarinen, the Eternal Hammerer of Finnish mythology, was said to have hammered out the firmament at the dawn of time. A myth for a grey-skied land.

  Having fallen from the sky evidently directed by nothing other than divine will, these aeroliths represented heaven on earth more satisfactorily than any terrestrial material or artefact sanctified by man. Worship must have begun long before it was possible to think of working the metal: there would have been little else to do with the mysterious burnished masses than to place them in the temples. But in more technological times, iron also throws down a moral gauntlet. According to the Qur’an (Sura 57:25), God sent down messengers, scripture and law; ‘And We sent down iron in which is mighty war, as well as many benefits for mankind, that Allah may test who it is that will help, unseen, Him and His messengers.’

  The Hayden Planetarium at the American Museum of Natural History in New York is home to some of the largest iron meteorites ever found. One prize is the Willamette meteorite, a fifteen-tonne black-and-silver lump the size of a small car and contoured like a piece of popcorn. It is almost pure metal–iron with a few per cent of nickel–polished by the touch of visitors over the course of the century that it has been on display. Visiting the museum one day, I find it crowded round by children like a tree in a playground. I touch the meteorite, and realize that I have done so entirely casually. I feel no magic–unlike the time when, at another museum, I was lucky enough to be allowed to hold in my hand a tiny meteorite that had fallen to earth having first been blasted off the surface of Mars. Other visitors touch the Willamette iron too, with curiosity and admiration, with rude familiarity or casual indifference, but not with special reverence. Paradoxically, it is the museum setting that makes this remarkable object seem ordinary, just one among hundreds of spectacular exhibits. I struggle to reimagine the metal mass lying in the crater of its own making deep in the Oregon forest where it was found. There, it could only look alien, truly an object from another world, a gift from the gods.

  The meteorite was found by chance in 1902 by a Welsh immigrant, Ellis Hughes, on land belonging, fittingly perhaps, to the Oregon Iron and Steel Company. Over a period of months, Hughes dug out the massive lump, constructed a cart and transported it the short distance to his house. Claiming to have found the meteorite on his land, he charged people twenty-five cents a time to see the curiosity. Unluckily, one of his visitors was the lawyer for Oregon Iron and Steel, who suspected that the iron had been taken from company land. Hughes duly lost the
complicated legal case that followed, and the company gained possession of the meteorite, later selling it to the donor who gave it to the museum.

  The Willamette meteorite is deeply pitted from centuries of corrosion in the humid woods. The best iron meteorites tend to be found near the poles, where they are preserved in ice. In 1818, the British Arctic explorer John Ross was surprised to come across Inuit hunters using steel tools. He suspected their metal was meteoritic in origin, but it was not until 1894 that an American expedition led by Robert Peary found the source–three of a group of meteorites that had been named by the Inuit according to size: ‘tent’, ‘man’, ‘woman’ and ‘dog’. With a great effort, Peary retrieved the thirty-one-tonne ‘tent’, which is also now in the American Museum of Natural History along with ‘woman’ and ‘dog’. The fourth of the group, ‘man’, was only found in the 1960s and was taken for display in Copenhagen.

  There is a delicious irony here: in order to recover the massive iron meteorites that he found in the Arctic ice Peary was obliged to build a railway. Its construction must have required the import of a quantity of iron far in excess of the mass of the meteorites–proof that celestial iron retains its power over the terrestrial.

  Iron meteorites made mighty objects of worship. But where sheer survival was the priority, the practical value of the metal could not be ignored. For a long time before it was discovered that it could be extracted from terrestrial ores, this metal from heaven was humankind’s main source of iron. Meteorites fall rarely, however, and so in societies from ancient Egypt to the Aztecs, iron was appreciated for its utility, yet at the same time often regarded as more precious than gold. Objects forged from it such as swords were functionally superior to any alternative. Some Bedouin believe that a man armed with a sword of meteoritic iron becomes invulnerable and all-conquering–something quite plausible given the superior qualities of the alloy. But the raw material was never abundant enough to equip armies, and so these weapons were reserved for ritual rather than practical use. The folk memory of a time when forging iron meant working with material from heaven begins to explain the mythic potency of iron and the smiths who have mastery over it.

  It was around 5,000 years ago, probably in Mesopotamia, that humankind gained the ability to smelt iron from widespread terrestrial ores. Gradually, reverence for these celestial objects was replaced by sheer incredulity. Well into the nineteenth century, even the most learned societies scorned the idea that lumps of pure metal could simply drop from the skies. On one occasion, the French Academy of Sciences passed a vote that iron meteorites did not exist. Only later were new techniques of analysis able to confirm their other-worldly nature. Specifically, iron meteorites tend to contain a significant proportion of nickel, which indicates that they cannot have been made from terrestrial ores–they are in effect a kind of stainless steel. Indeed, when alloy steel was first produced with nickel it was marketed in recognition of its superior properties as ‘meteor steel’. Conversely, if nickel is absent from the iron in an ancient object, this tells the archaeologist that the iron must have been smelted from ore.

  Although the words for all the metals in languages derived from Latin are gendered male (neuter in German), it is quite clear that the substances themselves connote gender quite independently of this linguistic happenstance. Gold and silver are linked with the sun and moon, which are almost universally regarded as male and female. In Greek mythology, for example, the sun god Apollo is clothed in gold, and his sister Artemis hunts with a silver bow, and for the Incas the moon was the incestuous bride of the sun. Other ancient metals may be more ambiguously gendered–mercury, for example, is the female principle to sulphur’s male in Chinese and Western alchemical theory, yet is linked to the male god Shiva in Hindu tradition. However, no metal is more clearly masculine than iron.

  When the Soviet press called Margaret Thatcher the Iron Lady for her persistent opposition to communism she took it as a compliment. Iron has always indicated strength and toughness–qualities almost synonymous in everyday usage, but which have rather precise meanings in materials science. The metal is generally hard, which means that it changes shape only very slightly when large forces are applied to it, but it is also less ductile and malleable than the other ancient metals. It is this unbending quality, not simply its hardness, that drives ‘iron’ as a metaphor. Churchill’s inspired coinage of the ‘iron curtain’ draws on this physical and attitudinal inflexibility, as well as making sly reference to Stalin, a nom de guerre meaning ‘steel’. Wellington, on the other hand, earned his nickname as the Iron Duke not through military prowess but for putting iron shutters on the windows of his London home as protection against ‘the mob’.

  Iron’s masculinity is reinforced by the metal’s eminent suitability for making weapons of war. However, this is not to say that fashioning a serviceable sword was an easy business. At Sutton Hoo in Suffolk, an Anglo-Saxon royal burial site uncovered in 1939, archaeologists found the helmet, made from a single piece of iron, thought to have belonged to King Raedwald, who died around 625 CE. They also found his sword and shield, though less well preserved. The blade of the sword was pattern-welded, a process that involves layering sheets of iron together to build up the shape of the blade, and which often results in a fine decorative pattern at the surface. In this way, desirable properties can be directed where they are needed–extreme hardness towards the edge of the blade, but a degree of flexibility in the core so that the weapon does not shatter upon impact. The skill of the forger lay in his intuitive knowledge of when to incorporate more carbon, obtained from the charcoal of his fire, into the molten iron to produce a harder steel. The Sutton Hoo visitor centre has arranged a display of iron sheets and rods of the kind that the swordsmith would have started with. They look like new grey plasticine. But without the heat of the forge, I find it hard to comprehend how they might be transformed into such a beautiful weapon, or to sense the patient, repetitive actions of heating and softening, hammering and quenching, with their implied cycle of death and rebirth by fire, that would have endowed the sword with ritual significance.

  The long-time rarity of iron and the technical difficulty of forging it made blacksmithing a trade of great prestige and mystique. The smithy was a place of hellish fire and stench from the sulphur released by unconverted ore. Wayland or Wieland, the blacksmith god of the Anglo-Saxons, like Hephaestus in Greek myth, is often represented as banished along with his forge to an island because his work is so repulsive. Yet the smith himself is the master of a necessary art and is known for his ingenuity as well as his skill. Ilmarinen, for example, in Finnish mythology, is an inventor as well as a smith.

  Swords made of iron were thus exceptionally precious artefacts–far too precious for use in real battle–and it is natural that they were seen as possessing mythic qualities. Although the metallurgy of these weapons is not always explicit, it seems that Excalibur, the sword of Arthurian legend, was made of iron–the name may derive from the Welsh caled, meaning hard, or from the Greek and Latin word for steel, chalybs. Sigurd’s sword, Gram, in Norse mythology is iron too. Iron craftsmanship has been raised to a high art in Japan, whose islands are poorly supplied with copper for bronze, or with the metals regarded as precious elsewhere. Kusanagi, the seventh-century sword that is part of the imperial regalia of Japan, is thus almost certainly made of iron, although it is impossible to know as the object, or its replica, is kept in a shrine where it is forbidden to be inspected.

  Not content with the scene in Das Rheingold where the hero Siegfried forges such a magic sword, Wagner also began an opera based on the legend of Wieland the Blacksmith (as well as another based on E. T. A. Hoffmann’s story ‘The Mines of Falun’, set in Sweden’s vast copper fields, which we will hear more of later). When excerpts from documents supposed to be Hitler’s diaries were published and then sensationally revealed to be forgeries in 1983, it was one of the more plausible aspects of the hoax that Hitler, an avowed Wagnerite, should have taken up the unfi
nished task.

  Though iron has long been accorded warlike male attributes, it is only with the advent of modern scientific methods that it has been possible to prove that the red of blood and of iron ore are due to the same cause. Yet the connection seems to have been sensed long before. When Siegfried slaughters the dragon Fafner with the sword he has made, he licks the dragon’s blood that has spilt on to his hand. The blood, like the sword, confers magical powers, and the hero is suddenly able to understand the birds in the forest. Perhaps even Irn-Bru–‘made in Scotland from girders’, according to the advertising–appeals in part because it flirts with the taboo against drinking blood, although the amount of iron it contains is minuscule, and its rusty colour is mainly due to E numbers.

  Though noted often enough, the metallic taste of blood was only explained in the mid eighteenth century. It is a story seldom found in histories of science. Yet the experiment was simple, and seems to have been first performed by Vincenzo Menghini, a Bologna physician, around 1745. He roasted the blood of various mammals, birds and fish as well as humans. He then poked among the solid residue with a magnetic knife and was pleased to find that particles of it were picked up on the blade. From five ounces of dog’s blood, he obtained nearly an ounce of solid material, the bulk of it being magnetic. (He presumably obtained similar results using human blood, although accounts do not explain how he got hold of it.)

  The experiment is very easy to repeat: place in a ramekin a tablespoon of blood (I drained mine off a pack of frozen chicken livers) and partially evaporate in a low oven. Transfer the sludgy residue to a small crucible or other container able to resist heat and roast to dryness. Scrape out the residue and grind to a coarse powder until it resembles coffee grounds. Spread the powder on a sheet of paper, and pass a moderately strong magnet closely over it. A few particles will be lifted on to the magnet.