Periodic Tales

by Hugh Aldersey-Williams

  The supposed author of The Triumphal Chariot, Basil Valentine, and his fellow alchemists regarded the amorphous grey phase of antimony–‘the sage’s matter’ and the ‘grey wolf of the philosophers’–as the tantalizing last stage before the realization of the philosophers’ stone because of its ambivalent capacity to produce either the lustre or the hue of gold, but never yet the two together.

  More alluring still is the metallic form of antimony, which has been celebrated since antiquity for its ability to solidify in a large crystalline mass that combines the gleam of precious metal with the faceted symmetries of gemstones. The phenomenon was undoubtedly noticed when the pure element, or regulus, was first made. The disc of crust that formed on top of the melt became known as ‘star antimony’ after the characteristic radiating pattern produced as the antimony crystallized in the cooling vessel.

  Isaac Newton, an alchemist as much as a mathematician and physicist, read Valentine and followed his recipe for making the regulus of antimony, thinking he might be able to use its gleaming surface in telescopes. One biographer invites us to believe that the stellate pattern he produced may have helped him to visualize the lines of force that led him to develop the theory of gravity. This seems fanciful to me. I can see how the patterns might inspire ideas about optics, which Newton was also investigating at the time of his experiments with antimony, but not gravity. I decide to go in search of antimony stars.

  For such beautiful artefacts of nature, they are surprisingly hard to find. I am quickly disabused of the idea that every Victorian collector would have owned one and that they would today be littering the store-rooms of provincial museums. However, photographs and illustrations show crystal patterns that are not acicular, which is to say like the chrome-spoked wheels of a sports car, converging on one central point, as would have to be the case for a diagram of gravitational force. Instead, the solid rink of antimony tends to be divided up into polygonal domains, smoother and larger near the centre of the disc and disintegrating into extravagantly foliate intaglio, like frost on a window, towards the outer edges according to its rate of cooling. The overall design is indeed star-like, not in the astronomical sense of a point source from which all light radiates, but in the manner of a child’s typical drawing of a star with a number of triangular points or, more particularly perhaps, like Renaissance emblems of the flaming sun.

  Perhaps this resemblance inspired another famous experiment with antimony. In 1650, one Nicolas le Febre was demonstrator in chemistry at the Jardin du Roi in Paris, where, for the edification of the young King Louis XIV, then a thoughtful eleven-year-old boy, he embarked upon ‘the Solar Calcination of Antimony’ by means of ‘Magical and Celestial Fire, drawn from the Rayes of the Sun by the help of a refracting or burning Glass’. Le Febre focused sunlight on to ‘the Stellat or starry Regulus’ and showed that the product of the reaction weighed more than the antimony he had started with. Perhaps the antimony star gave the young Louis the idea for the symbol that would shine over his long reign as the Sun King. Whether it did or not, the experiment was a milestone in modern chemistry for demonstrating proper method in place of alchemical obscurantism, and showing the first glimmerings of the understanding that the air itself contains chemical elements.

  Part Five: Earth

  Swedish Rock

  At the beginning of my chemical odyssey, I had traced a map of the world and placed a dot on it wherever one of the elements had been discovered. A very curious map it turned out to be. Aside from zinc and platinum, which were found without the assistance of Western science in India and the Americas respectively, all the dots relating to the naturally occurring elements fell in Europe. A cluster of dots in Berkeley, California, accounted for most of the elements heavier than uranium that have been made artificially following the discovery of nuclear fission. Another cluster at Dubna, north of Moscow, showed where some more recent radioactive elements have been synthesized.

  Europe showed four major hotspots of earlier date–London, boosted by the multiple successes of Davy and Ramsay, and Paris could claim just over a dozen elements apiece. Berlin, Geneva and Edinburgh also made their mark. But the two largest clusters of dots after Paris and London were both in Sweden, one at the old university city of Uppsala, and the other in the capital, Stockholm. Swedish science could claim the discovery of at least nineteen elements, more than a fifth of the naturally occurring total. Many of them, indeed, celebrate the places where they were found (yttrium, erbium, terbium and ytterbium named after the ore mine at Ytterby; holmium named after Stockholm itself) or after more or less romantic ideas of Scandinavia (scandium, thulium).

  (In old Europe, it is quite often the case that the elements are named for places associated with their discovery. For instance, strontium happens to be the only element named after a place in the British Isles, Strontian in Scotland. It’s more often the other way round in the United States, where chemical knowledge helpfully preceded westward expansion and the rush to uncover the riches of the wilderness. America’s Golden Hills and Silver Lakes were no idle poetic allusion; they expressed a direct connection to the earth into which adventurers hammered their tent pegs, and the hope, whether fulfilled or ultimately dashed, that these precious metals were to be found there. Aside from gold and silver, a dozen elements appear nakedly in town names, from the expected Irons, in Missouri and Utah, Leadville in Colorado, and Copper Center, Alaska, to the frankly surprising Sulphur, Oklahoma, Cobalt, Idaho, Antimony, Utah and Boron, California.)

  What made Sweden figure so largely in the story of the elements? I have been concerned throughout this book to suggest that we are familiar with many of the elements in a cultural way, that is to say without ever stepping into a laboratory. We know neon and sodium for the light they cast, iodine for its brown balm, chromium for its cheap shine. Others, such as sulphur, arsenic and plutonium, we tend to know more by reputation. The Swedish finds are mostly obscure by these measures–they include metals such as manganese and molybdenum, and a good handful of the elements known collectively as the rare earths, a group that includes all of those elements directly named after Swedish locations. They have not made a mark in the sense that they have become a byword for some human horror or delight. Yet these elements too have a cultural connection, and, as their toponymy implies, it is a connection that runs deep. Paris and London revealed new elements to the world because they were major centres of intellectual life. Berkeley and Dubna happened to be the sites chosen for the specialist machines needed to manufacture the heavier elements beyond uranium in the periodic table. But in Sweden’s case, the logic is unshiftable: her elements sprang from the very ground of the country.

  In order to learn more about this fertile womb of the elements, and how it was that there were men of science ready there to act as midwives, I decided to visit Sweden myself in order to find out how it was that two cities on the margins of Europe–one scarcely more than a small town–sustained an advantage over a period of a century and a half that enabled them to outstrip London and Paris in this race of discovery. During the first half of the seventeenth century, Sweden briefly became the new superpower of northern Europe, overrunning Norway, Finland and parts of Russia, northern Germany and the area now occupied by the Baltic states. Underwriting the expansion were Sweden’s vast reserves of iron and copper ore, which provided the necessary military and economic might. In time, these imperial ambitions were superseded by a new and more attractive idea, that of Scandinavia. But the mining continued, and it was from these mines, during the years of Sweden’s gentle decline, that this one nation made its lavish contribution to the periodic table. I muse on this history and how it is reflected in the Swedish elements, whose names became gradually less localized with each successive discovery, from yttrium in 1794 to scandium in 1879, as my plane flies over lakes and forests towards Stockholm.

  In Stockholm, I meet Hjalmar Fors, a young historian of chemistry with a wispy blond beard, who has agreed to lead me on a walking tour of the
scientific sights. We start in the Stortorget. It means big ‘square’, although it is a little square on the little island of Stadsholmen, Stockholm’s old town. Commanding one short side of the square is a red-washed merchant’s house with baroque gables and a psalm inscribed on a tablet above the door; it is where Carl Scheele, the nearly man of oxygen and chlorine, worked as a pharmacist around 1768. Our next stop is the national mint, which stands on the waterside hard by the Royal Palace. Here, in 1735, Georg Brandt, the Guardian of the Mint, speculated that the blue colour of the smalt ore obtained as a by-product from the royal copper mines might be the clue to a new element. The Board of Mines based at the mint was responsible for the analysis of minerals and maintained the first chemical laboratory in Sweden long before there was one at the university in Uppsala or anywhere else. This laboratory had been around for long enough to have fallen into some decay when Brandt came on the scene and set about modernizing it. It seems that Brandt may not have been thanked for this labour, however. Brandt was a rationalist, but his masters were Rosicrucians disinclined to let go of their mystical beliefs. In time, however, Brandt gained greater control over operations and was able to exert a more enlightened influence. During the later part of his career he continued to devote much energy to disproving charlatans’ claims to have transmuted silver and other metals into gold. It took him seven years to obtain the first specimen of cobalt metal. It was, Hjalmar tells me, the first truly modern discovery of a chemical element, that is to say the first to be supported by a solid notion of chemical theory, not merely alchemical hocus pocus.

  We move on, crossing over the water to Karl XII Square. Among the grand buildings overlooking the greenery is a substantial nineteenth-century yellow-ochre edifice that was the headquarters of the iron mines when Sweden was the world’s greatest exporter of the metal. An extended bas-relief frieze runs around the top of the building. It shows heroic figures engaged in every stage of the iron-making process, from extracting the ore, to smelting in the furnace, to casting the pigs. Lower down, the façade is punctuated by plaster medallions of Scheele, Berzelius and other great Swedish chemists. ‘I rather like this,’ says Hjalmar with a glint in his eye. ‘Nobody really knows who these guys are now. But there they still are up on the wall.’

  I am beginning to sense the vital connection not only between national prosperity and mining, but also between mining and chemical science. Sweden’s first true chemists were kept in employment one way or another by mining interests. Unlike their peers in Britain and France, they tended to be highly trained in the analysis of minerals. They worked at the Royal Mint or the Board of Mines or in direct collaboration with mine owners. They obtained their specimens from the mines and were frequent visitors themselves to the mines at Falun and Västmanland, a day or two’s ride from Stockholm or Uppsala. Here they were doubtless to be seen scrabbling through the tailings for exceptional stones or searching the exposed veins for glimmers of unusual colour, often performing their preliminary analyses in makeshift laboratories set up on site. These were no aristocrats amusing themselves in plush home laboratories, but realists aware that wealth came by virtue of hard labour out of the cold earth, and that any scientific knowledge gained in addition to that would be the more meritorious if it led to an increase in that wealth. And these men were justly rewarded for their realism by the business community whom they served: no medallions of Lavoisier or Cavendish are to be found on the commodity exchanges of Paris and London.

  We stop for a beer at a café in the Royal Hop Garden public park, with Scheele’s unreliable statue gazing down on us. Hjalmar tells me of his pipe-dream to rewrite the history of science by shifting the centre of gravity eastward to focus on the intellectual traffic across the Baltic, between the Scandinavian, German and Russian powers, ignoring for a change the bickering rivalry of the English and the French. It is a project that could restore to their rightful place in the chemical pantheon the shrinking violets of Sweden’s mining laboratories, men whose congenital modesty led them fatally to delay publication of their discoveries or even to shun it altogether, so helping to ensure they never received their due on the world stage–Johan Gahn, the discoverer of manganese; Torbern Bergman, the éminence grise behind many of the metals first isolated from Swedish sources, but the direct discoverer of none; and Scheele, who, having moved on from Stockholm, found even Uppsala too exciting, and spent the years when he might have been famous holed up in the little Västmanland town of Köping, batting away offers of employment from wealthy English and German patrons.

  The next day I take the train to Uppsala. Stockholm was the commercial and financial centre where the metals from up-country were assayed, traded and made into coin. What was Uppsala’s role? Uppsala has the oldest university in Scandinavia, established in 1477, but it wears its history lightly. The place hardly seems like an intellectual hothouse. There is life on its few shopping streets but no real bustle. Pedestrians and bikes weave happily around each other, and cars are few: it is easy to picture the city as it must have been two or three centuries ago. A fast-flowing river in a granite channel divides town from gown, but students are as thin on the ground as the shoppers.

  I meet Anders Lundgren, a lecturer in the history of science at the university, who sports a tangle of grey beard on a scale that Hjalmar Fors can only aspire to. As we stroll along, I observe idly what an extraordinarily genial place Uppsala seems to be. ‘Yes it is,’ Anders agrees. ‘Now. But not in the winter.’ It is early June. He points out a white dormered building where in the mid eighteenth century Uppsala’s first professors of chemistry, Johan Wallerius and Torbern Bergman, made their laboratories. It was in this building and its successors that most of Sweden’s element discoverers either learnt their art or passed it on as professors to the next generation. This was the case whether they came from Stockholm, like Anders Ekeberg (tantalum) and Per Cleve (holmium and thulium), or from the mining country, like Brandt (cobalt), or even from the Finnish territories like Johan Gadolin (yttrium): they all spent time in Uppsala. Peter Hjelm (molybdenum) and Lars Nilson (scandium) were two more Uppsala graduates. Scheele, meanwhile, ran the pharmacy in the town square where he made the first chlorine and oxygen, although he played no official part in academic life. Uppsala has a splendid university museum, the onion-domed Gustavianum, but, in what I am coming to accept as the inevitable Swedish fashion, it omits to celebrate even one of these men.

  Equidistant from Stockholm and the mines, Uppsala was the third point of a triangle–the thinking brain to the labouring hand and the pumping heart of the Swedish body politic. It was not a straightforward relationship, however. The crown needed the mines to fund its imperial ambitions, and the mine owners no doubt enjoyed the royal patronage. But it is not immediately clear why either of them needed the scientists. Anders Lundgren has studied the way mining influenced the development of science in Sweden. ‘Chemistry could never pay back to mining,’ he explains. The miners had no need of chemists to point out the valuable ores to them, and may well have resented these secular intruders with their blithe unconcern for the miners’ obscure traditions. And if the chemists were lucky enough to discover new elements, then these were of no interest either. They might fill odd gaps in theoretical understanding. ‘But theories of chemical affinity were no use in a blast furnace.’

  Yet the chemists did gain support such that for a long time in Sweden chemistry was probably the only science to offer the prospect of a decent career. The crown gained intellectual prestige from supporting the laboratory at the Board of Mines, and mine owners emulated this largesse on their own modest scale. Some mine owners indeed, such as Berzelius’s patron and collaborator Wilhelm Hisinger, were scholars in their own right. The national ‘minerography’ that Hisinger produced at the age of twenty-four, for example–a kind of atlas of mineral resources–was less the stake-claiming project of an avaricious prospector, far more a product of humanistic pleasure in knowledge for its own sake.

  Though it may do littl
e to commemorate them, the Gustavianum did contain one further clue to the extraordinary success of Sweden’s chemists. I have indicated elsewhere that the discovery of elements often relies on the possession of some special technology, and that given this device or that technique, the discoveries then often come in a rush. It is easy to believe that in the eighteenth century there was no such technology in place to assist in prising the rare earths and other elements from the grudging Swedish rock. This is so in the sense that no high-powered gadget suddenly unlocked the floodgates, and the discoveries came instead in painful fits and starts over a long period. Yet during all this time there was one tool which no self-respecting Swedish chemist was ever without: his blow-pipe. The specimen in the museum is perhaps twenty centimetres in length and appears to be made of iron. It is essentially a thin, elegantly tapered tube not unlike a cigarette-holder. At one end it is slightly flared so as to produce a good seal with the user’s mouth. At the other, the airway is bent through ninety degrees and forced through a small hole, while a separate outlet drains off spittle as in a musical wind instrument.

  This simplest of equipment was the key to the analysis of unfamiliar minerals. It had the great advantage that it could be used in the field. According to a guide published by one distinguished Swedish mineralogist, it amounted to nothing less than a ‘pocket laboratory’. Even Goethe, a keen scientific amateur, had Berzelius instruct him in its use. The blow-pipe was eventually superseded by the spectroscope, but it remained a feature of analytical chemistry teaching until the middle of the twentieth century; Anders Lundgren remembers trying one out at school, and describes to me how it works. Though simple enough, it demands powerful lungs and fiendish skill if it is to deliver good results. Its great versatility lies in the fact that it may be used to blow a jet of air through different regions of a flame, thereby producing a high-temperature zone that is able either to oxidize or to reduce (the reverse chemical process) a mineral sample positioned in the way.