Mauve

by Simon Garfield

  Even in the 1850s, no one was sure what caused this disease. There were plenty of theories, most involving marshlands and airborne infection, but, despite vague hunches from Livingstone and others no one had yet made the scientific link with mosquitoes.

  Treatment for malaria was more straightforward, although often difficult to secure. Up until 1820, when the French chemist–pharmacists Pelletier and Caventou isolated quinine from cinchona bark, many physicians still proffered such remedies as three days of blood-letting, or treatment with mercury, or three bottles of brandy. The superstitious believed that carrying a spider in a nutshell, or eating one, would cure the disease.

  But this was the era of the new alkaloid. Cinchona bark (and roots and leaves) contained not only quinine (named after the Spanish spelling of ‘kina’, the Peruvian word for bark), but also cinchonine, and in the next two decades, two more alkaloids were isolated from the tree, quinidine and cinchonidine. Each had a slightly different molecular structure, and none was quite as effective against malaria as pure quinine (but nonetheless sold as such). In the same period, the two Frenchmen also isolated the strychnine from St Ignatius’s beans, and other chemists found other alkaloids – caffeine in coffee beans and codeine in opium.

  Quinine was in limited supply, and thus expensive. The cinchona tree is about the size of a plum tree with leaves like ivy, and was found almost exclusively in Bolivia and Peru. By 1852, the Indian Government was spending more than £7,000 annually on cinchona bark, and £25,000 for supplies of pure quinine. The East India Company was spending about £100,000 annually. Predictably, this was not intended to treat the poor, and still bought nothing like the 750 tons of bark required by the British army in India alone.

  The clamour for quinine from the great European imperialists was immense, and Britain and Holland mounted costly attempts to grow cinchona seeds in India and Java; the British tried to grow the tree for commercial use in Kew Gardens. The initial planting missions failed, as explorers would often plant the wrong seeds in the wrong place. Some did get rich on the disease, the most notorious being John Sappington who marketed Dr Sappington’s Pills in the Mississippi valley by persuading local churchmen to ring their bells in the evening to remind people to take them. Sappington had capitalised on the one fundamental property of quinine – its scarcity – and had added other worthless substances to his pills to make his supplies go further. In London and Paris, the cost of bark was about £1 per pound, but as it took approximately 2 lb of bark to treat each person, only the well-off got better. When, in the 1840s and 1850s, hundreds of thousands began demanding quinine as a prophylactic, it was clear that it had become the most desirable drug in the world.

  In his room in Oxford Street, August Hofmann had a theory as to how quinine might be made in the laboratory. To his credit, he seems not to have been interested primarily in the fortune to be made by such a discovery. He had noted how naphtha, which he called the ‘beautiful’ hydrocarbon, produced in great quantities in the manufacture of coal-gas, may be converted by a relatively straightforward process into a crystalline alkaloid known as naphthalidine. This substance was found to contain 20 equivalents of carbon, nine of hydrogen and one of nitrogen.

  Coal-gas contains more than 200 different chemical compounds, although only a few of them were known to Hofmann and his students in 1850. These are split between hydrocarbons (which include naphthalene, benzene, and toluene) and those compounds containing oxygen (the most important being phenol or carbolic acid).

  Hofmann believed that, as the formula for quinine differed from that for naphthalidine by only two additional molecules of hydrogen and oxygen, it might be possible to make quinine from the existing compound just by adding water. ‘We cannot, of course, expect to induce the water to enter merely by placing it in contact,’ he wrote. ‘But a happy experiment may attain this end by the discovery of an appropriate metamorphic process.’

  William Perkin was only eleven when Hofmann published this theory, and he read it only after he was admitted to the Royal College in 1853. He soon recognised the importance of the idea. ‘I was ambitious enough to want to work on this subject,’ he recalled, and was motivated further three years later by Hofmann’s chance remark that artificial quinine was now surely within their grasp. What he had not grasped was that the apparent simplicity of quinine’s constituent parts would so thoroughly conceal the hidden complexity of their architecture. The ‘happy experiment’ desired by his mentor would not be forthcoming, or at least not in the way he had anticipated.

  * On another visit Hofmann found one of his students making good use of the gas fires to cook his meals. ‘At lunch time he used to grill sausages in the empty, scoured dish of the sand-bath … or bake ham and eggs for him and his friends,’ Hofmann’s student Volhard recalled. ‘Hofmann had often observed the not-quite chemical-smelling scent; one day he followed it and appeared quite unannounced in the makeshift kitchen … He dealt with his English pupil in masterly manner. No word of reproach, but he kept him busy until the last sausage was wholly charred.’

  4

  THE RECIPE

  She said she was going to do it, and by golly, on Thursday, she did it. Because she is the first female secretary of state of Missouri, Judi Moriarty changed the color of the state manual to … mauve.

  For those who don’t know, mauve is a delicate shade of purple.

  ‘I wanted a color that represents me and made a statement,’ Moriarty said when introducing the new state manual. ‘It’s in good taste, and it has a lot of beauty.’

  St Louis Post-Dispatch, 1994

  In the first months of 1856, Gustave Flaubert began Madame Bovary, Karl Bechstein opened his piano factory, the plans for the bell Big Ben were drawn up at a foundry in Whitechapel and Queen Victoria instituted the Victoria Cross. During the Easter holidays of that year, August Hofmann returned briefly to Germany, and William Perkin retired to his laboratory on the top floor of his home in the East End of London. Perkin’s domestic workplace contained a small table and a few shelves for bottles. He had constructed a furnace in the fireplace. There was no running water or gas supply, and the room was lit by old glass spirit lamps. It was an amateur’s laboratory, an enthusiast’s collection of stained beakers and test tubes and rudimentary chemicals. The room smelled of ammonia. The table on which he worked was stained with spillage from previous efforts, and probably of ink as well. He was surrounded by landscape paintings and early photographs, and by jugs and mugs and other domestic trinkets that were as alien to a laboratory as delicate soda crystals were to any other house in this smoky residential neighbourhood. It was an unexpected setting for one of chemistry’s most romantic and significant moments.

  Looking back, Perkin adopted a rather nonchalant tone to describe his actions. ‘I was endeavouring to convert an artificial base into the natural alkaloid quinine, but my experiment, instead of yielding the colourless quinine, gave a reddish powder. With a desire to understand this particular result, a different base of more simple construction was selected, viz. aniline, and in this case obtained a perfectly black product. This was purified and dried, and when digested with spirits of wine gave the mauve dye.’

  In effect, the discovery at that time of one apparently simple molecule could rarely claim such a far-reaching impact on the development of science and industry. The room in his father’s house afforded views of the ships in the London docks, and of the London and Blackwall Railway, an inspiring vision of travel and progress. But Perkin’s view of the distance held no glimpse of the future, no vision of the Lancashire factories 200 miles away which soon would reverberate with the sound of his invention.

  The chemistry was simple, involving the then popular ‘additive and subtractive’ method: find a compound that looks similar to the one you are trying to create -in this case, Perkin chose allyltoluidine – and used two standard processes, distillation and oxidisation, to alter its formula by adding oxygen and removing hydrogen (in the form of water). It was a naive ma
noeuvre.

  Most chemists, particularly those trained by Hofmann at the Royal College, would have thrown the reddish powder into a rubbish bin, and begun again. It was Perkin’s intuitive talent – an enquiring mind in an unsupervised laboratory – that led him to experiment further, and test the effect of this procedure on aniline. And it was a mark of his skill that, in analysing the crude black product that resulted, he was able to separate out the five per cent that contained his colour.

  By the time Perkin found mauve, aniline had been linked with colorants and colour-producing reactions for thirty years. The liquid had first been discovered by the Prussian chemist Otto Unverdorben in 1826, one of several products isolated from the distillation of natural vegetable indigo. Some years later the chemist Friedlieb Runge obtained it from the distillation of coal-tar, and found it gave a blue colour when combined with chloride of lime. But such colours were considered to have no practical use. In the unlikely event that a scientist would have thought a particular tint might be useful in the dyeing of a woman’s dress, they would most certainly have believed such fripperies unworthy of their calling.

  But Perkin was excited about his unexpected find. Chemists blundered every day; partly, that was the nature of their job. But only occasionally did their errors lead them in interesting directions. Perkin stained a silk cloth with his discovery, and did little more than admire the new shade. It was, he realised, a brilliant and lustrous colour, and he found that it did not fade with washing or prolonged exposure to light. The problem he faced was what to do with it next. ‘After showing this colouring matter to several friends, I was advised to consider the possibility of manufacturing it upon the large scale.’

  One of these friends was Arthur Church, with whom Perkin discussed the seemingly insurmountable problem of making more than a small beaker of his colour. Liquid aniline was hard to obtain in quantity, and expensive; Perkin had never set foot inside a factory, and knew nothing of manufacturing chemicals outside the laboratory; and he knew no one in the textile or dyeing trades to whom he could turn for advice.

  Both Perkin and Church knew that their mentor would disapprove of any schemes not directly connected with research. They resolved not to tell Hofmann about mauve when he returned from Germany, certainly not until Perkin had established its exact properties and had conducted further experiments.

  For this, Perkin moved to slightly largely premises – a hut in his garden. He enlisted the help of his brother Thomas, and together they made several batches of mauve, each purer and more concentrated than the last. Through a friend of his brother, Perkin learnt the name of a highly regarded dye works in Scotland, and decided to send the owner some samples of cloth. He received a lengthy reply from a man called Robert Pullar in the middle of June, and his tone was encouraging.

  ‘If your discovery does not make the goods too expensive it is decidedly one of the most valuable that has come out for a very long time. This colour is one which has been very much wanted in all classes of goods and could not be had fast on silk and only at great expense on cotton yarns. I inclose you patterns of the best lilac we have on cotton. It is done by only one house in the United Kingdom, Andrews of Manchester, and they get any price they wish for it, but even it is not quite fast, it does not stand the tests that yours does and fades by exposure to air.’

  Pullar was twenty-eight, and was later described by a general manager of his company as possessing ‘a mind always looking forward for something new and better’. His large dye works in Mill Street, Perth, had recently received a royal warrant, and now advertised itself proudly as silk dyemakers to the Queen. Robert Pullar liked to quote Faraday: ‘Without experiment I am nothing; still try, for who knows what is possible.’ Perkin had been lucky in his choice of adviser; he was to discover later that not all dyers or printers were as progressive or encouraging.

  Pullar explained to Perkin that he could not put a price on the colour, not until he had tested it himself in a dyeing vat. ‘If the quantity of yarn or cloth that could be soaked in one gallon of your liquor would take up all the colouring matter in that gallon, then I would say that the price would be much too great …’ If this happened, the dyestuff required to colour one pound of silk or cotton would cost about five shillings – ‘far too much for a manufacturer to pay’.

  Pullar offered to help Perkin in any way he could, and regretted that he did not live nearer London to meet him in person. ‘We are always very desirous here to have every thing new, as we do a large trade in manufacturing and a new colour in the goods is of great importance.’

  Perkin showed this letter to Arthur Church, who encouraged him to take out a patent immediately. But there was a problem with Perkin’s age, as patents were usually only granted to those over twenty-one. He sought counsel’s opinion, and was advised that since a patent was a gift from the Crown, the matter of age should be immaterial. Perkin filed his application at the end of August 1856, when he was eighteen. But then he began to wonder: what good would it do him? Just how much was a new colour worth?

  *

  New colours had been discovered by chance since ancient times, and some magnificent myths had evolved. A sheep dog belonging to Hercules, while walking along a beach in Tyre, bit into a mollusc which turned his mouth the colour of coagulated blood. This became known as Royal or Tyrian purple. It brought prosperity to Tyre around 1500 BC, and for centuries remained the most exclusive animal dye money could buy. It was the colour of high achievement and ostentatious wealth, and came to symbolise sovereignty and the highest offices of the legal system. Within Jewish practice, the dye was used on the fringes of prayer shawls; in the army, the wearing of purple woollen strips was used to denote rank. Purple was also the colour of Cleopatra’s barge, and Julius Caesar decreed that the colour could be worn only by the emperor and his household.

  It was prohibitively expensive. The molluscs – Murex brandaris from the Italian coast or Murex trunculus, located first on the Phoenician coast – were drained of their glandular mucus in their thousands to make a single robe. Pliny described how, during autumn and winter, the shellfish were crushed, salted for three days and then boiled for ten. The resultant colour resembled ‘the sea, the air and a clear sky’, suggesting that Tyrian purple defined not one particular shade but a rich spectrum from blue to black. The dying process varied from port to port, and might have water or honey mixed in to achieve different hues.

  Of the other animal dyes the most popular was cochineal, the crimson dye from cactus insects. Introduced into Europe by the Spanish from Mexico (then New Spain) in the sixteenth century, it was widely used as cloth dye, artists’ pigment, and much later a food colorant, but again required a huge seasonal harvest – about 17,000 dried insects for a single ounce of dye. What may have been the first English dye house was established for cochineal in Bow, east London, in 1643, and the scarlet became known as Bow-Dye and was described in terms of bruised flesh.

  Vegetable dyes tended to be cheaper, and in greater supply. In Perkin’s day the most common were madder and indigo, the ancient red and blue dyes used for cloth and cosmetics. Madder, from the roots of some 35 species of plant found in Europe and Asia, has been found in the cloth of mummies and is mentioned by Herodotus, and is probably the first dye to be used as camouflage – Alexander the Great spattering his army with red to persuade the Persians that they had been critically wounded in earlier battle. In ‘The Former Age’, c.1374, Chaucer depicts the idea of man’s early innocence when

  No mader, welde, or wood [woad] no litestere [dyer]

  Ne Knew; the flees [fleece] was of his former hewe.

  Indigo, used not only as dye and pigment but also an astringent lotion, derived from the leaf of Indigofera tinctoria, a shrub-like plant that was soaked in water and then beaten with bamboo to hasten oxidation. During this process the liquid changes colour from dark green to blue, when it is then heated, filtered and formed into a paste. Before the colonisation of America, it came predominantly from India in
the form of dye-cakes, and this ancient derivation held firm to the time when Perkin could observe the colour in women’s fashions in the West End.

  There were several other important plant dyes – carthamus, woad, saffron, brazilwood and turmeric – but even these represented an extremely narrow range of colours, confined variously to red, blue, yellow, brown and black. Woad, again known to Pliny and used commonly by ancient Britons as a facial and body dye, contained a similar colouring matter to indigo, although derived from a different plant and containing about one-tenth the tinctorial power.

  Throughout much of the eighteenth century the greatest advances in dyeing technique were made in France, but between 1794 and 1818 an American working in London called Edward Bancroft claimed many significant improvements. Bancroft patented three new natural dyes, including the yellow quercitron, and wrote the first scientific treatise on dyeing in English. His Experimental Researches Concerning the Philosophy of Permanent Colours combined exact chemical observations with personal anecdotes: he noted, for example, how his favourite purple coat hardly faded though he wore it for several weeks. Bancroft had a further claim on posterity, as he was later exposed as a double agent during the American Revolution, working both for the British government and for Benjamin Franklin.

  The process of dyeing cloth had not changed much in centuries, and the most skilled practitioners had passed complex and guarded procedures through generations. But in New York in 1823, William Partridge published A Practical Treatise on Dyeing of Woollen, Cotton and Skein Silk, with the Manufacture of Broadcloths and Cassimeres Including the Most Improved Methods in the West of England, for thirty years the standard text, in which all the most popular dyes were disclosed like magicians’ secrets and presented like cookery recipes. To prepare the fastest blue, for example, you would need an English vat containing ‘five times one hundred and twelve pounds of the best woad, five pounds of umbro madder, one peck of Cornell and bran, the refuse of wheat, four pounds of copperas, and a quarter of a peck of dry slacked lime’.