Periodic Tales

by Hugh Aldersey-Williams

  In 1995, however, it reopened as the Curie Museum. I meet the museum’s coordinator, Marité Amrani, who has a refreshingly unParisian enthusiasm for her work. She shows me examples of radium-branded products before leading me into the rooms where Marie Curie did most of her work. She assures me that the place has been pronounced safe, but the dishevelled state of the cupboards and the antique bottles of chemicals left on the shelves make me wonder. I examine a sample of pitchblende, a dull-grey rock with hints of pinkish sparkle, and wonder what emanations it is still giving forth. Displayed on the wall is a page of Marie Curie’s notebook, and alongside it a blackened radio-graph of the same page betraying the heavy contamination. Her lab coat–black with white polka dots–betrays a hint of Parisian chic. In a corner is the mahogany box that once contained the gramme of radium that Marie accepted as a gift from the women of America who had raised the $100,000 necessary to acquire it. Inside the box is a solid cylinder of lead the size of a Stilton cheese with a small well dropped into the centre to house the radioactive source. I try and fail to lift it–‘It weighs forty-three kilogrammes,’ Marité tells me. ‘And today you would use much more lead.’

  One of Marie Curie’s greatest legacies is the peer effect that she created. ‘She welcomed many women into the laboratory here,’ says Marité. ‘If someone was made for science, she would encourage them.’ Marie’s daughter Irène was her most obvious protegée, who went on to win her own Nobel Prize jointly with her husband–the second woman after her mother in both distinctions–in 1935. Another was Marguerite Perey, who discovered her own new element, francium, in 1939. Perey rose, like the restaurant plongeur who becomes the chef, from test-tube washer to be first Marie’s personal preparatory assistant and then a fine scientist in her own right. Her discovery, made on the eve of the Second World War, met with none of the fuss that so irritated the Curies. Perey had first proposed the name catium and the symbol Cm for the element preceding radium in the periodic table (because of its predicted likelihood of forming highly reactive positive ions, or cations), but by the time that new element names next came up for official consideration, in 1947, a flurry of other radioactive elements had been discovered as a consequence of the Manhattan Project. One of these new elements had a better claim to the symbol Cm: curium. Perey accepted her second choice of name, francium. In 1962, she became the first woman to be elected to the French Academy of Sciences, which had chauvinistically excluded both Marie and Irène. Perhaps she named her element wisely in the end.

  On my return from Paris, I got off the Eurostar and made my way to my parents’ house, which I was using as a London way-station. I went to wipe from my black shoes the chalk dust that had settled upon them from walking through the Paris parks, and was astonished to find along with the tins of Meltonian polish a rectangular carton of black leather dye branded ‘radium’ in bold 1960s lettering.

  Nightglow of Dystopia

  Gas was the principal means of lighting city streets and town houses from the middle of the nineteenth century. Its hissing white light was excitedly evoked in its prime and was still missed long after its demise. By the time that incandescent electric light was taking over around the turn of the century, the mere image of gaslight was sufficient to deliver a powerful nostalgic kick. In the famous German wartime song ‘Lili Marleen’, written in 1915, Lili is simply presented standing underneath a lamp-post (Laterne). By the time of the Second World War, however, when the song enjoyed renewed popularity, the English translation has her repackaged as ‘Lily of the lamplight’ the allure is as much for a bygone age of innocence as for the femme fatale.

  The wonder of artificial illumination naturally finds its way into descriptions of the urban world. Yet its light is not simply light. It radiates, illuminates and leaves shadows according to its kind, and in doing so establishes moods to which writers have been more or less sensitive. Dark deeds might be done by its beams, but gaslight itself–understandably since it was the first public lighting–was an innocent marvel. Even in novels beset with shadows, such as Joseph Conrad’s The Secret Agent, gaslight comes out of it well. Indeed, Conrad is at pains to point out that its light is completely neutral. At one point, it catches the anti-heroine Winnie Verloc’s cheeks glowing ‘with an orange hue’. This orange is no effect of the illumination; it is the composite of a red blush seen through her bilious yellow complexion. The white of the gaslight shows things in their true colours.

  Writers have greeted the modern innovation of sodium street lighting differently. Like gas, the incandescent lamps that sodium would duly replace shone a generous white light, combining light of many colours, created by the flow of an electric current through a metal filament. Sodium on the other hand shines light of a single wavelength–589 nanometres. When light from a sodium discharge strikes a colourful object all we see is the fraction of that 589-nanometre light that is reflected and no other colour. This monochrome wash is deceptive, not truth-telling; it soaks everything in a nicotinic glare such that it is no longer possible to perceive colour accurately.

  The first sodium lights were installed in the streets adjacent to the lighting manufacturers themselves, Osram in Berlin and Philips near Maastricht in the Netherlands. Purley Way, near the Philips factory in Croydon, was the chosen British test site in 1932. As sodium street lamps became more commonplace after the Second World War, their staining light came to the attention of writers seeking to convey a sinister city atmosphere. In Nausea, Jean-Paul Sartre’s alter ego, the young writer Roquentin, is tormented by his pointless existence, the ‘Nausea’ of the title; at one point he crosses the street to the pavement opposite, drawn by ‘a solitary gas lamp, like a lighthouse’, and is astonished to find that ‘The Nausea has stayed over there, in the yellow light’. The poet John Betjeman, while fond of the Metroland which it illumined, reviled the ‘yellow vomit’ thrown out by the new concrete ‘gallows overhead’. A generation later, J. M. Coetzee makes this idea work harder in his novel Age of Iron, set in apartheid-era South Africa. Coetzee’s narrator, Mrs Curren, a retired professor who is dying of cancer, is being driven with her maid into one of the townships, where they will discover the body of the maid’s son murdered by the police. The car splashes ‘through pools on the uneven road…under the sick orange of the streetlights’. The light is a metaphor both for her cancer and for the cancer that is destroying the country. Anthony Burgess and J. G. Ballard also bathe their dystopian visions in sodium light. The element was surely a worn cliché by the time that Will Self, in The Book of Dave, has his eponymous London taxi driver eyeing up potential fares loitering ‘frowsty under the sodium lamps’.

  Joseph O’Neill manages to refresh the image in his 2008 novel, Netherland. The central character is coming to terms with his wife’s decision to leave him. Staring out from the balcony of his apartment in New York’s Chelsea Hotel, he bitterly twists a metaphor of potential sunrise into a Götterdämmerung sunset:

  a succession of cross-streets glowed as if each held a dawn. The tail lights, the coarse blaze of deserted office buildings, the lit storefronts, the orange fuzz of the street lanterns: all this garbage of light had been refined into a radiant atmosphere that rested in a low silver heap over Midtown and introduced to my mind the mad thought that the final twilight was upon New York.

  The Reagan-era Three Californias trilogy by science-fiction writer Kim Stanley Robinson presents different scenarios for the golden state. The second novel in the series, The Gold Coast, depicts perhaps the most likely of these futures, neither post-nuclear nor ecotopian. Here, Robinson riffs more extendedly on the lights of Los Angeles and their elemental origins:

  The great gridwork of light.

  Tungsten, neon, sodium, mercury, halogen, xenon.

  At groundlevel, square grids of orange sodium streetlights.

  All kinds of things burn.

  Mercury vapor lamps: blue crystals over the freeways, the condos, the parking lots.

  Eyezapping xenon, glaring on the malls, the stad
ium, Disneyland.

  Great halogen lighthouse beams from the airport, snapping around the night sky.

  An ambulance light, pulsing red below.

  Ceaseless succession, redgreenyellow, redgreenyellow.

  Headlights and taillights, red and white blood cells, pushed through a leukemic body of light.

  There’s a brake light in your brain.

  A billion lights. (Ten million people.) How many kilowatts per hour?

  Grid laid over grid, from the mountains to the sea. A billion lights.

  Ah yes: Orange County.

  On every continent, sodium is now the colour of the city at night and the principal means of our knowing this element, its lurid, unlovely light an inescapable feature of metropolitan life. Even the manufacturers and authorities responsible for installing them recognize that sodium lamps are no triumph of aesthetics, but they are favoured nevertheless because they are more energy-efficient than the alternatives. Attempts to change over to whiter lights based on mixtures of other chemical vapours have been thwarted by successive oil crises, and so we go about our nocturnal lives under sodium’s singular glare.

  It is not the 589-nanometre colour that offends. In another context, this can offer cheer, as when sea-salt tints the flames of a driftwood fire. It is the foggy ubiquity of it. I confess I share the general distaste for this artificial illumination inflicted citywide, though I have only happy memories of the single sodium lamp that shone from the other side of the street into my bedroom as a child. I can recall watching how it flickered with fresh-washed pink (due to neon added to activate the sodium at a lower voltage) when first shocked into action on damp autumn evenings before brightening and passing through red and orange on its way to the full radiance that meant I had no need of a night light. I had not read any dystopian novels then.

  It was not its characteristic light that led chemists to the discovery of sodium, as was to be the case with various elements identified later. In 1801 Humphry Davy moved from Bristol to take up a position as director of the laboratory at the newly founded Royal Institution in London. He took with him his galvanic piles, the primitive batteries with which he had lately begun to experiment, and a hunch that the electricity they generated might be key to the discovery of ‘the true elements’ of substances.

  At the Royal Institution, he built more powerful piles by interleaving dozens of square plates of copper and zinc in elongated boxes like Christmas packs of After Eight Mints. He summarized his first experiments with the new apparatus in a prize lecture to the Royal Society in November 1806. It was a piece of work of such promise that it immediately secured his international reputation, including the award from Napoleon that provided the reason for his later trip to France. Having concluded an investigation of the electrolysis of pure water and various solutions by this method, Davy turned his attention to melted salts. The following October, he immersed the platinum wire electrode of his battery into molten potash and almost immediately managed to decompose the material and produce a highly reactive new metal. Davy ‘danced about the room in ecstatic delight at the end of it’, according to his cousin Edmund, who had been enlisted as an assistant. A few days later, Davy repeated the experiment with the corrosively alkaline caustic soda, or sodium hydroxide, in place of the potash, and the same thing happened–another new metal.

  In November, he returned to the Royal Society to give the same prize lecture, a performance that would trump the achievement of the previous year. Davy described how ‘a most intense light was exhibited at the negative wire, and a column of flame, which seemed to be owing to the developement of combustible matter, arose from the point of contact’. The metal obtained from the potash was liquid and looked like mercury, while that from the soda was silvery and solid. Both were dangerously reactive: ‘the globules often burnt at the moment of their formation, and sometimes violently exploded and separated into smaller globules, which flew with great velocity through the air in a state of vivid combustion, producing a beautiful effect of continued jets of fire’. Davy announced that he had chosen the names potassium and sodium for the new elements. But were they metals? They were extraordinarily light. If it were not for the fact that they exploded on contact with water, they would easily float on its surface. He found they floated even on naphtha, a petroleum oil considerably less dense than water. He concluded that their exceptional lightness should not be considered as overruling their other properties, such as high electrical conductivity, which showed them to be indubitably metallic. Using his uniquely powerful electrolytic apparatus, Davy had just discovered the two most reactive metals known to science.

  Chemists strongly suspected that other minerals would prove to contain further explosively reactive new metals that simply awaited a powerful enough force to prise them free. One of these minerals was lime, which Lavoisier had included in his list of ‘simple substances’ on this promise; another was magnesia, which Joseph Black in Edinburgh had shown to be chemically analogous to lime and therefore likely to be a compound of a closely related metal. Strontia and baryta were two more substances that had been obtained by Black’s pupil Charles Hope, who had noted their coloured flames (red and green respectively) as indicating the presence of new elements. Davy proceeded to submit each of these so-called alkaline earths in turn to his electrolytic treatment, this time using an electrode of liquid mercury to capture the metals as they were released in an amalgam before they could burn away. Through the course of 1808, Davy succeeded in isolating, one after another, calcium, magnesium, strontium and barium.

  Chemistry was not Davy’s only talent. He was also a romantic poet of serious promise. Robert Southey, later Poet Laureate, included some of Davy’s verse in the Annual Anthology that he edited, and admiringly called him ‘the young chemist, the young everything’. Davy saw no contradiction between his science and his art, linking the study of nature with a love of the beautiful and the sublime. The first stanza of a poem he wrote at this time seems to incorporate images of the inflammable metals released so dramatically from unyielding minerals:

  Lo o’er the earth the kindling spirits pour

  The flames of life that bounteous Nature gives;

  The limpid dew becomes a rosy flower.

  The insensate dust awakes, and moves, and lives.

  Two further members of the highly reactive group of elements known as the alkali metals were found, unlike Davy’s sodium and potassium, by means that did depend upon the signature light of their salts. In 1859, Robert Bunsen and Gustav Kirchhoff in Heidelberg made a spectroscope, a kind of sophisticated prism that enables scientists to identify elements by separating out the colours they give in a flame (provided perhaps by one of Bunsen’s famous burners) into characteristic lines like a barcode. Bunsen and Kirchhoff used their new gadget to make a systematic investigation of the dissolved ingredients of mineral waters in case an undiscovered element should lurk there. By chemically removing the obvious salts of soda and lime, and the less obvious strontia and magnesia, they were left with a solution of rarer salts, from which they then evaporated all the water. Placing the solid residue of this solution in a flame, Bunsen and Kirchhoff observed a new, blue, light, which could only be due to an undiscovered element. They named it caesium, after caesius, the Latin word for the colour of the sky. A few months later, they followed a similar procedure on a mineral sample from Saxony and saw dark-red lines of another new element: rubidium.

  A fifth alkali metal, lithium, had been found some years before by more conventional methods (named therefore not for its light in a flame but after the earth–lithos in Greek–in which it was found). Now, thanks to spectroscopy, it seemed that these metals were everywhere. One morning Bunsen surprised his coworker by announcing, ‘Do you know where I found lithium? In tobacco ashes!’ The element had previously been thought to be very rare.

  The existence of these relatively uncommon, but hardly rare, elements, caesium, rubidium and lithium, had simply been obscured by the omnipresence of sodium.
Sodium is by far the most abundant alkali metal in the salt of the earth, and its bright yellow light easily washes out other colours from a flame. When astronomers complain of light pollution, it is often sodium street lights they have in mind. Edwin Hubble escaped the glare of ‘Orange county’ by retreating to a mountaintop observatory north of Pasadena, where he recorded the motions of the galaxies that led to his discovery of the expanding universe. But it wasn’t sodium that caused him difficulties. Potassium burns with a mauve flame which can sometimes be seen in a gunpowder explosion or when lighting a match. One night Hubble was excited to detect a potassium spectrum while he examined the galaxies through the world’s most powerful telescope. But it soon became apparent that the reading must be false. Eventually Hubble realized that the equipment had picked up the light from the potassium in the match that he had used to light his pipe.

  The makers of fireworks, unlike the suppliers of artists’ paints or prepared foods, are under no obligation to declare the chemical content of their goods. To those with rudimentary knowledge, their names may suggest certain ingredients. My cheap Fifth of November box made broken-English promises of ‘silver glittering’, ‘green diamonds fountain’ and ‘golden nuggets’. Probably magnesium, copper and sodium, I thought. But verification comes only when the skies are illuminated in the elements’ signature shades.

  Different yellows and oranges are created by sodium salts, powdered charcoal and iron filings, for example. Green has traditionally been made using copper salts, such as verdigris. Long before they knew about the other elements that could answer their wishes, pyrotechnists wanted to recreate the full spectrum of colours through their craft. The Chinese achieved something approaching the effect by using ribbons of coloured paper as filters through which the light of their exploding gunpowder could shine. As early as the mid eighteenth century, fireworks were advertised as offering proper rainbow colours. But in truth, it seems that the colours are brighter in description than they can ever have been in the fireworks themselves. Gold and silver were the predominant tones, obtained from various mixtures of powdered iron and the black sulphide ore of antimony, which sparkled orange and white respectively.