There were detailed descriptions of how to prepare the lime, followed by directions to chop the woad into small lumps with a spade, and gradually add other ingredients to water set at 195 degrees Fahrenheit. The instructions ran on for several pages. ‘The vat should be set about four or five o’clock in the afternoon, and be attended and stirred again at nine o’clock the same evening,’ before being cooled. By this stage the result should be bottle-green. The dyer was then directed up again at five in the morning, and told to add more lime or indigo to lighten the colour. Bubbles and skin and increasing thickness would denote a good fermentation, which should then be boiled again and cooled, and boiled and cooled, and more lime added, and then it was time for the wool dipping. This was where matters became complicated. You really needed two vats of woad, one two months old, the other new, and the wool should be dipped in each in turn. The temperatures of the dye should be finely held at 125°F–130°F, then cooled overnight, then heated to 155°F–165°F, and then more woad added, with more lime, bran, madder and indigo. If the vats were skilfully managed it should colour 220 pounds of wool every week; within six weeks, the dyer should have four hundred pounds of dark blue wool, two hundred of half-blue, and two of very light. But this was only attainable if the very best woad and indigo were used, and here there were problems: ‘There is probably no article more uncertain in its strength and quality than woad,’ Partridge concluded. He advised buying only the very strongest, as ‘any considerable variation in this particular will prove very disastrous to the operator, however skilful he may be in his profession, and will be altogether ruinous to a young beginner’.
As with cinchona bark, the supply of plant dyes was often limited to specific regions and hampered by a nation’s attempts to monopolise production. Clothes manufacturers were forced to use the colours available in the dyers’ vats; trends in colour were fashioned less by taste than by the vagaries of war and efficiencies of foreign ports. It stood to reason that a colour you could make on demand in a laboratory somewhere, with a constant strength and purity, would surely be worth an awful lot of money.
*
Initially, Perkin called his discovery Tyrian purple, the better to elevate its worth. His detractors, those who believed his discovery insignificant, preferred to call it purple sludge. Chief amongst these was August Hofmann, who learnt of Perkin’s new colour after the summer holidays, along with some distressing news of his protégé’s future. The two arranged a meeting, during which Perkin told Hofmann that he was considering manufacturing mauve commercially. He also said that this would require him to leave the Royal College of Chemistry. ‘At this he appeared much annoyed,’ Perkin recalled at a memorial meeting to mark Hofmann’s death in 1892. ‘[He] spoke in a very discouraging manner, making me feel that perhaps I might be taking a false step which might ruin my future prospects.’
The objection caused a serious rift between them – probably the first cross words they had exchanged. ‘Hofmann perhaps anticipated that the undertaking would be a failure, and was very sorry to think that I should be so foolish as to leave my scientific work for such an object, especially as I was then but a lad of eighteen years of age. I must confess that one of my great fears on entering into technical work was that it might prevent my continuing research …’*
Hofmann and his colleagues would have found it hard to imagine how one of the most promising scientific careers could be summarily abandoned in pursuit of a colour. Chemists came across new colours at random almost every week, and just as easily dismissed them as being an undesirable or irrelevant side-effect of their missions. Besides, some chemists had deliberately produced artificial dyes before mauve, and had observed how well they had coloured silk or wool, but had not attempted to manufacture them in commercial quantities. The first had been the picric acid made by Woulfe in 1771 from indigo and nitric acid (it dyed silk bright yellow), and in 1834 Runge had used carbolic acid to make aurin (a red colour), and pittacal (a deep blue) was obtained from beechwood tar. Other colours encouraged the development of implausible histories, not least murexide, which surfaced in small quantities in Manchester dye works in the 1850s and was said to come from the excrement of serpents (rather than its true source, bird-droppings). But the quantities of synthetic dyes in use at the time of the Great Exhibition of 1851 was so small as to not merit any mention in the huge accompanying Reports.
Then there was the bright crimson produced by Perkin and Church some months before, again considered unworthy of further exploitation. Perkin’s purple might have been cast aside in a similar manner were it not for the further encouragement he received from Robert Pullar in Perth towards the end of 1856.
The scale of Pullar’s dye works must have seemed an impressive place to a young man unfamiliar with industrial practices. The presence of scientists, however, was nothing new to print works, and some had employed their own textile chemists from 1815. In fact, Perkin’s discovery came at a time when the state of technical advance in Britain’s dye and printing works was ideally poised to exploit it. Production levels in the textile industry were increasing at unprecedented rates. Exports in the calico business, for example, increased fourfold between 1851 and 1857, from about 6,500,000 items to 27 million. Employment in the silk industry doubled to 150,000 people between 1846 and 1857. At one of the many jubilee celebrations of Perkin’s discovery, the chemist C. J. T. Cronshaw told a gathering of the Society of Chemical Industry: ‘If a fairy godmother had given Perkin the chance of choosing the precise moment for his discovery, he could not have selected a more appropriate or more auspicious time.’
This was not only true of the position of Britain’s dye works. Perkin could only have discovered mauve when he did because of the particular state of chemical knowledge. He was born not long after the Cumbrian chemist John Dalton had theorised that atoms combine with each other in definite numbers, thus leading to the establishment of chemical formulae. But Perkin conducted his early experiments at a time when so much was yet unknown, thus allowing for his productive error over the synthesis of quinine. If Perkin had been born twenty years later, he would have known how fruitless his search would have been, and thus would not have blundered into mauve. John Dalton, incidentally, died twelve years before Perkin’s discovery, but the beauty would have been lost on him anyway: in 1794 he had been the first person to describe colour blindness – his own.
The principal reason that August Hofmann would have failed to share Perkin’s enthusiasm for his new colour was because he would not have been unduly surprised by it. Even before he came to London he had heard Liebig predict that artificial dyes would someday be made from a substance such as aniline. But the roots of his disapproval lay in the current relationship between pure and applied science, which really meant the relationship between science and industry, two worlds set against each other by deficiencies in education.
In 1853, Lord Lyon Playfair had travelled through Germany and France at the request of the Prince Consort, specifically to report back on the state of foreign scientific and technical education. His analysis was damning: the great universities of Europe had already forged a strong connection between laboratory work and industry, whereas in industrial Britain he found only an ‘overweening respect for practice and contempt for science’. He found the greatest culprit to be the severe shortcomings in basic teaching. Playfair feared the impact on Britain in the event of free trade, suggesting that when ‘the raw materials confined to one country become readily available to all at a slight difference in cost, then the competition in industry must become a competition in intellect’.
The Great Exhibition of 1851 inspired many lectures sponsored by the Society of Arts, and some of them singled out a peculiar irony: while Britain shook the world with its industrial clout, it was virtually alone in Europe in lacking a well-defined system of technical education.
The same year saw the opening of Owens College in Manchester, and at its inaugural gala the college’s professor of chemistry Edward Fran
kland suggested that Britain’s textile industry was ill-prepared for the future. Its pre-eminence in manufacture would only be maintained by far stronger links with men of science. ‘The advantages of chemistry to the chemical manufacturer, the dyer and calico printer are almost too obvious to require comment,’ he said. ‘These processes cannot be carried out without some knowledge of our science, yet with the exception of some few firms … this knowledge is too often only superficial, sufficient to prevent egregious blunders and ruinous losses, but inadequate to seize upon and turn to advantage the numerous hints which are almost sure to be constantly furnished in all manufacturing processes.’
The Chemical Society, founded in 1841, drew its few hundred members from manufacturing and academic backgrounds, and prided itself on the links between the two. In 1853, the president of the society, Frank Daubeny, seemed to express relief when he informed his members that Professor Robert Bunsen’s work on volcanic eruptions could be used as ‘undeniable evidence of the extensive utility of our pursuits’. Four years later, the new president W. A. Miller spoke of the invention of mauve as further proof of the burgeoning usefulness of their skills. ‘One of our Fellows, Mr Perkin, has afforded me the opportunity of bringing before you the results of a successful application of abstract science to an immediate practical purpose.’ At the time, he could hardly have known of the immense implications of this observation.
In fact, the successful application was still some months away, but when it came it did little to placate those who believed that Perkin’s intellect could be better employed elsewhere. Even in 1862, it appeared that Hofmann accepted Perkin’s breakthrough only very grudgingly. After visiting the International Exhibition that year in London, he still wished that ‘the care and time involved in an undertaking of such magnitude may not divert [Perkin] from the path of scientific enquiry, for which he has proved himself eminently qualified’. Such a pure attitude ran counter to the dominant industrial ambition of the age: the pursuit of wealth.
In retrospect, it appears that Perkin shared some doubts about his commercial ambitions, though not for fear of being thought greedy. He resolved to regard his foray into industry as a means to an end. Writing to his friend Heinrich Caro, he stated that at the time of his discovery, ‘for a scientific man to be connected with manufacturing was looked upon as infra dig.’ Scientists who crossed the line were treated as pariahs, betrayers of their calling. Perkin was worried that, should he fail, there would be no way back. ‘Even poor Mansfield, as soon as he started to be a manufacturer, sold his scientific instruments (I have his balance which I purchased from him) evidently with the idea that his research days were over,’ Perkin wrote. ‘This public opinion and example made me dread becoming a manufacturer, because research was the principal ambition of my life, and I determined so far as in me lay that I would not give this up, whatever I did.’
At the time, however, he kept this desire very much to himself, and was treated by some with disdain. ‘It was said that by my example I had done harm to science and diverted the minds of young men from pure to applied science, and it is possible that for a short time some were attracted to the study of chemistry from other than truly scientific motives.’ In other words, Perkin’s discovery affected the whole nature of scientific investigation: for the first time, people realised that the study of chemistry could make them rich.
How to Make Mauve: a modern method
Caution: Petroleum ether is extremely flammable. All evaporations should be performed under hoods (fume cupboards). No naked flames in the lab, please. Disposal of all chemical wastes should follow the standard procedures.
You will need:
2.3ml of water in a 5ml conical flask, to which add
52μl of aniline
6oμl of o-toluidine
I22mg of p-toluidine
600μl of 2N sulphuric acid
Stir, using a large spin vane, until the reactants have dissolved, heating gently if necessary. After solution, add 30mg of potassium dichromate in 160μl of water.
Stir for two hours. Very soon after the addition of K2Cr2O7, the solution will turn a vibrant purple. At the end of the reaction time, use a Pasteur filter pipette to draw off the liquid portion, which can be discarded.
Transfer the solid to a ceramic filter with a seated filter paper already in place. Using gentle suction filtration, wash the dark solid with distilled water until the washing is clear. Dry the remaining solid in an oven at 110°c for 30 minutes. Then wash the solid with petroleum ether until the washings are clear. Dry again for 10 minutes at 110°c.
Wash the remaining solid with a 25 per cent methanol/water solution until the liquid runs clear, being very careful not to contaminate the product. Evaporate this aqueous/alcoholic solution, transferring to a 5ml conical flask as soon as the total volume allows. After evaporation is complete, add 300μl of 100 per cent methanol to the remaining solid, shake to dissolve any soluble materials, and use a filter pipette to transfer the liquid to a clean 3ml flask. Carefully evaporate the liquid in a conical flask until it has a volume of 30μl or less. As the solution volume gets smaller, the purple colour should grow more intense. This final methanol solution contains the ultimate product – a 2mg yield of mauve.
This isn’t much mauve. To get more, you might like to ask all your friends or an eager class of chemistry students to conduct the same experiment, and then pool all the methanol solutions, before evaporating this en masse. A small piece of cotton cloth can then be dipped in the solution, then rinsed in water and dried. It makes a nice pocket handkerchief; the solution will colour three slim bow ties.
How to make a Nesselrode: a traditional method.
The Nesselrode pudding, a frozen tower of chestnut, fruit, custard and cream, is the creation of Monsieur Mouy, chef to Count Karl Vasilyevich Nesselrode, the nineteenth-century Russian statesman best known for his role in the creation of the Holy Alliance. The pudding appears, to some acclaim, in one of the lengthy dinner parties in Proust’s A la recherche du temps perdu, but these days is seldom made, largely due to health considerations.
The Nesselrode has been described as ‘a two-day event, not counting the evening with the orange peel’. One day takes place in the freezer.
You will need (for six people):
½ cup chestnut purée
¼ cup glacé cherries
½ cup candied orange peel
½ cup Marsala
½ cup each currants and sultanas
1 big splash maraschino
2 cups whipping cream
Custard: 2 cups milk, 5 eggs, ¾ cup sugar
Chop the candied fruit and work in the Marsala. Soak the currants and sultanas in warm water and dry. Heat the milk to boiling. Separate the eggs, discard the whites but place the yolks in a bowl and add the sugar, beating vigorously until the mixture is frothy. Pour the milk over the mixture in the bowl, then place the contents of the bowl in the saucepan. Stir frequently and cook over low heat until the custard thickens and then strain through a sieve. Mix the chestnut purée, the maraschino and the custard together well, then add all the fruit. Whip the cream until stiff, and fold into the mixture. Pour into a mould lined with waxed paper or greased up like an oily whippet. Cover with foil and freeze for a full day.
It is a costly dish, but it will feed a big celebration. For a special effect, such as a birthday or where lettering is required to inform people why they have come, the surface may be coloured with a myriad of dyes. Try Annatto, Quinoline Yellow, Fast Green, Citrus Red No. 2, E160C, E100, E150d and E129.
* While Hofmann objected to Perkin’s new obsession, it was not solely due to his pursuit of a practical application of his learning. Hofmann himself was involved in several such projects: in 1854 he analysed the spa waters of Harrogate for the Harrogate Water Committee; he sat on the chemical sub-committee assigned to examine the decay of the limestone and dolomite structure of the Houses of Parliament (no solution agreed upon); and in 1859 the Metropolitan Board of Works asked Ho
fmann to consider the possibilities for deodorisation.
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HINDRANCE AND SYNTHESIS
Patrick mixed paints – a delicate shadowy mauve, a scarlet, a rich blue, a pale sharp green. The paintings, when they arrived, were done suddenly and fast. I watched, from inside my head. Patrick would always smile apologetically, and both of us would laugh nervously, and then his face would set into a detached, slightly furious look, and he would take a stab at the canvas, and then a rush.
A square head appeared, and a decorative trellis of flowers. Various faces, shadowed in the delicate mauve, existed for a moment, and then were wiped away. I was fascinated by how the ghosts of the expunged forms continued to exist and to make the subsequent versions more complex and substantial. Purple is Patrick’s favourite colour. It is not mine. But I became entranced by the shadowy half-depths of that particular mauve running across the canvas.
A. S. Byatt on being captured by Patrick Heron, Modern Painters, 1998
The way Robert Pullar remembers it, William Perkin arrived in Perth, Scotland, in the early winter of 1856 with some problems on his mind. He explained to Pullar that he had severe doubts about his decision to leave the steady world of research for one of commercial industry. He had misgivings about his ability to compete in business, and this insecurity led to more fundamental concerns. Just how valuable would mauve be? How would dyers react to a complete change in the way colour was derived? Would anyone be willing to adapt to new methods of dyeing after employing the same techniques for generations? And although mauve successfully dyed silk, why was it proving so much harder to apply the new colour to cotton?
Mauve Page 5