Combustion is a rapid form of oxidation, the chemical combination of a substance with oxygen, while what goes on in the stomach is the opposite process, known as reduction, which is accomplished by the action of bacteria. The simplest reduction of sulphur yields another foul gas, hydrogen sulphide. Between them these two basic chemical processes account for a vast range of sulphur chemistry that is essential to life. The handful of noxious compounds so made undoubtedly give the element its evil reputation, but this reputation would not exist if these compounds were not locked into a cycle with others responsible for more pleasant sensations. For example, the various pungent odours of the alliums arise from this chemistry, with onion, garlic, leeks and chives each containing a different sulphur compound in minute quantities. During cooking, these compounds are converted into substances far sweeter than sugar, related to those used in artificial sweeteners. In the cabbage family, on the other hand, cooking gradually converts sulphur-containing compounds into smellier forms, which is one of the things that makes overcooked brussels sprouts so unappealing. The sulphur compounds released when we digest our food are passed out of the body in excrement, and especially, because so many of them are volatile, as flatus and bad breath. One of them, methyl mercaptan, allegedly the world’s smelliest molecule, is added to otherwise odourless natural gas so that we may be sensitive to leaking pipes. Though the sulphur is only present in tiny amounts, its foul odours and association with bodily functions are enough to explain its devilish cultural reputation among the elements.
The sulphur I saw on the quay at Galveston was a by-product of the local petrochemical industry. It made me think of the fumaroles under the Gulf of Mexico where specialized marine bacteria synthesize pure yellow sulphur out of the gases released from the bowels (the cliché apt for once) of the earth. I knew, of course, that the element was in fact recovered from hydrogen sulphide in the natural gas brought ashore from the offshore platforms, but in both cases the gas is ultimately the product of the decay of palaeozoic plants. Even the ‘smell of the sea’, it has recently been found, is owing to a sulphurous gas, this time dimethyl sulphide, released by living microbes in surface waters.
The smell of the sea must have beckoned the sailors who embarked at Plymouth on Christmas Eve 1835 at the beginning of what was to be a seven-year circumnavigation of the globe with the purpose of surveying the oceans and collecting scientific specimens. Their ship was called HMS Sulphur.
The expedition was similar in intent to that of HMS Beagle, which was then on the final leg of its own long voyage, and shortly to set ashore its dangerous cargo of Charles Darwin and all his specimens and new ideas. It is recounted in the two volumes of a Narrative of a Voyage Round the World, performed in Her Majesty’s Ship Sulphur, during the years 1836–1842, including details of the Naval Operations in China, from Dec. 1840, to Nov. 1841 by the ship’s captain, Edward Belcher. The surgeon on board, Richard Brinsley Hinds, produced three companion volumes describing the mammalia, mollusca and flora they saw on the voyage.
Belcher’s Sulphur, a ten-gun bomb vessel, was the third of three Royal Navy ships of that name. The first of them already bore this curious name when the navy bought it from its American owners in 1778. I have been unable to discover a specific reason for its chemical christening. I suppose that it was simply regarded as a suitable sign of belligerence since the second HMS Sulphur, purchased in 1797, took part in the Battle of Copenhagen alongside sister ships named Volcano, Explosion and Terror. Like the second, the third Sulphur was equipped with mortars that were able to lob explosive shells or ‘bombs’ forward from the bow rather than simply firing cannon from the sides. This capability was to be put to use when the ship was sidetracked from its scientific mission into military conflict with China during the First Opium War.
Her route took the Sulphur via Tenerife and the Cape Verde Islands, around Cape Horn, and up the South American coast to Panama, from where she made three huge perambulations of the north and south Pacific, plumbing the depths and scanning the horizons for unknown islands, before passing westward through the Pacific islands and the Malacca and Madagascar straits and round the Cape of Good Hope to home. The main task was survey work, for which the ship was equipped with chronometers, both ‘pocket’ and ‘heavy’, and rockets that could be sent up to provide time signals. Comparing chronometer readings at two stations on land at the moment the rocket flare is seen allows the distance between them to be calculated. As the crew took readings on the island of Gorgona, off the Colombian coast, some faulty rockets went off at ground level. Fortunately, though, there was enough gunpowder to try again. A second signal was successfully improvised by hauling some bags of powder up a tall tree and igniting them there.
At Nootka Sound in British Columbia, ‘Indians’ gathered round the Sulphur in their canoes seeking to trade fish and furs. Some form of entertainment seemed to be in order, and so Captain Belcher sportingly went ashore at dusk with ‘a magic-lanthorn and supply of fireworks’. The lantern show inspired delight, but the fear occasioned by the fireworks was such that ‘I had several women grasping me by each hand’.
The Sulphur’s voyage up to this point had amounted to a Cook’s tour of some of the world’s geological hotspots–the Canaries, Panama, the Sandwich Islands (Hawaii), Alaska. Belcher went yomping up Mexican volcanoes as if they were the Munros. Five thousand feet up on the rim of one of the three craters of the Viejo volcano, he plunged a thermometer into the soil and found the temperature went off the scale. ‘It speedily warmed me to an unpleasant degree through thick boots.’ Another time, at Tepitapa, where the Lake of Managua falls into the Nicaragua River, they dallied by a sulphur spring: ‘My thermometer was not graduated above 120°, therefore I cannot state more than that eggs were boiled in it,’ Belcher reported. ‘Crystallization was abundant on the small stones between which it flowed, and some specimens I examined were a mixture of sulphur and calcareous matter. The taste was not unpleasant.’ Belcher does not on this or any other occasion think it worth noting the coincidence of his vessel’s name.
Meanwhile, Surgeon Hinds and his scientific assistants observed or collected whelks, clams and scallops, lemurs and jerboas, parrots and kingfishers, mimosas, euphorbias, cactuses and oaks. The discovery that sulphur plays a role in plant and animal life had been made a generation or two earlier from investigations of horseradish and ox bile. The men perhaps would have been aware of this, although they would not have known, for example, that their clams fed for bacteria around submarine sulphur vents. Nor were they fortunate enough, as the Sulphur passed through the Malacca Strait, to discover the Sumatran titan arum, or corpse flower, whose massive bloom bursts open once every several years to release a cadaverous stink based on a cocktail of dimethyl polysulphides.
But more sulphurous adventures lay in wait. At Singapore, Belcher picked up orders from the Admiralty to proceed instantly to Canton in order to take part in naval operations against the Chinese. The First Opium War had broken out in 1839, when Britain seized Hong Kong in an attempt to force China to open to trade. The Sulphur’s botanist on board made his excuses and left to return to Kew, ‘conceiving himself out of his sphere in our prospective cruize’. On 7 January 1841, the Sulphur took up her position at the outer defences of the Canton River and began shelling the enemy, ‘giving lower Chuenpee a dose of grape and canister’. Then they attacked the junks. One rocket set off the magazine of the ship closest to the Chinese flagship ‘and she blew up in great style’. The British prosecuted their success by capturing an important fort, only to find that the enemy had removed its guns in the night. ‘A “flare up” we might easily have had, as the lines were plentifully strewed with powder.’
On their return to Spithead, the surviving crew of the Sulphur were pleased to learn they had qualified for a bonus under a scheme brought in during their absence to compensate them for the longevity of their voyage. Edward Belcher was knighted. Richard Hinds opened his cases to find that many of his specimens had been ‘re
duced to powder’ by insects and later learnt that 200 species of plants laboriously gathered from California and the Pacific islands were ‘already described’.
What the circumnavigation of HMS Sulphur unwittingly demonstrated was the ubiquitous occurrence and daily utility of the element for which she was named. Her crew paid their respects at its frequent eruptions from the earth and put it to use for science, revelry and war. The ship returned to a country where the inventor Thomas Hancock had just obtained a patent for the use of sulphur in the vulcanization of rubber, and the brimstone terrors of the Book of Revelation had been sufficiently tamed that the name of Lucifer could be tolerated as a brand of matches.
Pee is for Phosphorus
Long before phosphorus came to scientific light, there was Phosphorus, gentle usher of the dawn:
Sweet Phosphor, bring the day!
Light will repay
The wrongs of night;
Sweet Phosphor, bring the day!
So wrote Francis Quarles in his Emblems Divine and Moral of 1635, in a typical evocation of the morning star known in Greek as Phosphoros and Latinized as Phosphorus. The morning star we know now–and in truth it was known then, although poetic fancy favoured the idea of a self-generating light–is the planet Venus, which is always seen in the sky near the sun, and brightly reflects its light so to appear to us as the herald of the new day. The same planet does double duty as the evening star Hesperus, which catches the light of the sun just set, and to which the poets, natural late risers, refer rather more often than Phosphorus.
So useful were these luminous companions of the dawn and dusk that they continued to gain lyric employment long after science had shown the names to be falsely applied. Poetic Phosphorus was not yet at its zenith when one Hennig Brand of Hamburg took it for the name of the new element he discovered, probably in 1669. Slowly, though, the poets began to assimilate the additional meaning. In the nineteenth century, for example, Tennyson’s ‘In Memoriam’ still invokes Phosphor to indicate the time of day, as does Keats atop Ben Nevis. But in his poem ‘Lamia’, Keats is drawn to the idea that this natural glow might be captured by man–literally caged, in fact–as he describes a portal ‘Where hung a silver lamp, whose phosphor glow / Reflected in the slabbed steps below, / Mild as a star in water’. This image corresponds in turn to accounts of ‘perpetual lamps’, which were presumably based on phosphorescent materials, supposedly used by early Christians such as Saint Augustine.
The idea of a substance glowing with light that seems not to be fire is a compelling one, and elemental phosphorus does indeed glow in the dark. The light comes from the combustion of short-lived oxides that are created at its surface when it is exposed to air, something only confirmed in 1974, 300 years after Brand first observed the eerie light. But not everything that we tend to describe as phosphorescent actually owes its glow to phosphorus. Marine phosphorescence–observed at night in warm waters when the sea blooms milky white like the negative of a photograph–occurs when enzymes trigger chemical reactions in bioluminescent bacteria and does not involve phosphorus itself. Similar chemistry is observed in other luminescent organisms from fireflies to honey fungus.
Phosphorus is involved in some equally peculiar goings-on, however. Herring, for example, are said to emit light as they rot away. Intrigued by this unlikely claim, I bought some herring, and set one out to decay in the garage where the ammonia smell would not be too oppressive. Two nights later, I felt my way towards where I had put the fish. At first, I saw nothing. But as my eyes grew accustomed to the blackness, I was amazed to detect the faintest of glows following the torpedo shape of the herring, the brightest part lying towards the head. In The Rings of Saturn, W. G. Sebald says ‘this glowing of the lifeless herring’ remains to be explained. But the chemistry is straightforward. Along with the ammonia is generated a smaller quantity of its phosphorus analogue, phosphine, and a related compound, diphosphine, which is spontaneously combustible. The slow flame of this gas burning as it seeps forth from the fishy carcass is what produces the light. The same reaction has been proposed to explain tales of human spontaneous combustion. In Bleak House, Charles Dickens memorably has the rag-and-bone man Krook meet his end in this way. His lodger finds him a ‘crumpled black thing’ having suffered a death ‘engendered in the corrupted humours of the vicious body itself’. Dickens reveals that he had read up on human spontaneous combustion when he cites a number of ‘true’ cases in his account of the inquest into Krook’s death. When the episode first appeared in serial form, Dickens was criticized by the philosopher George Henry Lewes and others for giving credence to pseudoscientific ideas. But he stoutly defended his position in the preface to the published novel, adding a reference to a further case only recently reported. Puzzling stories of human spontaneous combustion still crop up from time to time, although first-hand witnesses tend to be thin on the ground. Phosphorus released by the body has not been eliminated as a possible source of ignition.
Hennig Brand was an alchemist who had married well, and with his wife’s indulgence, he was able to maintain a laboratory on the Michaelisplatz in the shadow of the newly completed St Michaelis church in the new part of the thriving Hanseatic port of Hamburg. He was an upright, if somewhat pompous, citizen, earning the satirical nickname of Dr Teutonicus, although his real name now seems more appropriate than any alternative: Brand is the German for fire. He believed according to the alchemical orthodoxy that there might be a divine connection between the gold he sought and that abundant golden liquid, human urine. This led him to collect and evaporate a large quantity of urine and then to distil the residue. He noticed that the vapour which came off had a ghostly glow, and that the waxy white material which condensed from it had the same inner light. It also burst into flame as it escaped from the retort and came into contact with the air. He was astonished to find that the light was not dependent upon the heat of the experiment, but seemed to be an intrinsic property of the mysterious substance. Brand realized that he was now in possession of something quite remarkable, a miraculous light that sprang from the substance of our own bodies. Perhaps it was the philosopher’s stone itself. At the very least, it had to be a sign. Diligent alchemist that he was, he spent the next few years in a futile attempt to convert his find into gold. Others sought to take advantage of Brand’s success, but the philosopher Gottfried Leibniz, then in the employ of Duke Johann Friedrich of Hanover, befriended the alchemist and set up contracts for him whereby he was able in the end to obtain at least some gold for his efforts.
Brand’s experiment–the earliest documented piece of science that led to the discovery of a new element, even if it was not appreciated as such at the time–looked like the sort of thing I ought to be able to repeat at home. I could make my own phosphorus from my own urine.
But first, if I was to have any chance of succeeding, I would need a more precise recipe. Where was this to be found? Brand did not publish his work, at first keeping it secret, only occasionally spilling crucial details in exchange for a few thalers. With these meagre clues, Brand’s rivals were unable to repeat his achievement for some years. On the rare occasions when somebody succeeded, they too took steps to preserve the mystery: it naturally heightened people’s interest to unveil a glowing specimen of the miraculous substance if one kept quiet about how it was made.
There are many paintings of the famous scientists associated with the discovery of the elements–foremost among them Jacques-Louis David’s sumptuous portrait of the great chemical modernizer Antoine Lavoisier and his wife–but very few that show them at work, or that purport to show the moment of discovery. However, the discovery of phosphorus is an exception. Of this there is a marvellous painting made by Joseph Wright. It bears the cunningly revealing title: The Alchymist, In Search of the Philosopher’s Stone, Discovers Phosphorus, and prays for the successful Conclusion of his operation, as was the custom of the Ancient Chymical Astrologers.
I went to see the painting in the city art gallery of D
erby, where Wright was born and worked for most of his life. There was much in it to wonder at. Why is the ‘alchemist’, Brand, wearing monkish robes and working in a vaulted Gothic room if this is 1669? The scene is more like a Frankenstein film set than a proper laboratory. Such anachronisms are probably deliberate, as we shall see. For the moment, though, I need to focus on the experiment in progress. Wright shows Brand kneeling, hands outspread in amazement, before a brightly glowing glass flask which sits on a tripod stool. Next to this is a plastered brick chimney flue, free-standing in the room, which is fed by an unseen fire. A pipe runs out from the top of the flue and down into the flask, and some luminous material is pouring along this pipe into the flask. It is clear that no heat is being applied to the flask, and that every effort has been made to exclude air from the apparatus, for the joint between the pipe and the flask is carefully sealed with clay. Both of these details emphasize that the generated light is to be regarded as a natural wonder and not as any sleight of hand on the part of the alchemist.
Periodic Tales Page 11