In March 1856, teenage chemistry student William Henry Perkin synthesised a purple dye from coal tar, the inconvenient waste of the burgeoning coal-gas industry.1 One hundred and fifty years on, has the significance of this discovery been forgotten?

In Short
  • High street rage for 'mauve' among the ladies of Paris and London marks the beginning of the modern, organic chemicals industry

purple material

Source: istockphoto

The young William Henry Perkin (1838-1907), whose interests included mechanics, photography, art and chemistry, was educated at the City of London School. From 1853 he was a student, and then a research assistant, at the Royal College of Chemistry in London.2 Head of the college at that time was the German chemist August Wilhelm Hofmann, renowned for his research into the aromatic amine, aniline (phenylamine), and the 'ammonia type' formula for amines, which was used to describe the constituents of chemical compounds in the days before structural theories became available.  

Like many chemists of this time, Hofmann was investigating ways of transforming coal tar into useful products, but with no success. Perkin, working in his home laboratory during Easter of 1856, was trying to synthesise quinine via condensation of two molecules of allyltoluidine. When that failed, he wisely decided to repeat the experiment with the simplest aromatic amine, aniline. Trituration of the dark mass, obtained via oxidation of the aniline, with alcohol, afforded a purple solution that dyed a piece of silk a brilliant purple.3

The birth of the modern chemical industry

Dyes, or colorants, were valuable products in the 1850s, consumed in vast quantities by calico, or cotton, printers and dyers in the textile producing regions of Lancashire and Scotland. So in August 1856, the astute 18-year old, Perkin, filed a patent for his process: the conversion of benzene into nitrobenzene, reduction to aniline, and oxidation to afford a mixture that included a few per cent of the novel dye. Advantageously, Perkin's aniline dye, or Tyrian purple as it was originally called, showed resistance to light and washing, unlike other purple dyes. However, while the dye adhered fast to silk, it did not stick to cotton. To encourage textile dyers to buy his aniline dye, Perkin devised a way to attach the dye to cotton fabrics by using tannic acid.  

The dyers were reluctant to change from the traditional natural dyes, however, until the synthetic colorant was adopted in France late in 1858. So while Perkin's manufacturing process and the method of application were together a triumph of methodology, based on observation and a keen insight in one so young, the dye succeeded commercially only because the colour purple was all the rage among the fashionable ladies of Paris, and then of London. The colour became known as mauve, from the French word for the mallow flower, though in 1863 Perkin gave his dye a more scientific name, mauveine. (Intriguingly, the structure of mauveine was established only in 1993 by O. Meth-Cohn and M. Smith.)4

And thus the high-street rage for mauve started the modern organic chemical industry which, at first, was based on aromatic intermediates derived from coal-tar hydrocarbons.5 The second important synthetic dye to come on the market was a red. Variously known as magenta or fuchsine, this dye was again discovered by chance, this time by a chemist in Lyon, France. The dye was formed only because aniline contained significant amounts of the aromatic amines o- and p-toluidine. In 1861, a blue aryl derivative of the red was synthesised, and in 1863, Hofmann speculated correctly that alkyl derivatives would afford violets.6

This was just the beginning. From Perkin's discovery there arose not only dyestuffs, but also pharmaceutical products, polymers, and explosives, as well as the first industrial research laboratories, academic-industrial collaborations, and modern academic, organic chemistry. During 1869-70, Perkin and, independently, German chemists Carl Graebe, Carl Liebermann and Heinrich Caro independently discovered routes to synthetic alizarin, the important red colorant in the root of the madder plant, whose large-scale cultivation soon after ceased.  

After 1870, however, through mastery of organic chemistry based on Kekulé's benzene ring theory and superior research and marketing organisations, the dyes industry passed to Germany.7 By 1897, the Germans had taken over leadership from the UK's industry and were manufacturing synthetic indigo by one of two routes, starting with either benzene or naphthalene. (In 1883 Adolf Baeyer wrote the first almost correct structure for indigo in a letter to his industrial collaborator, Heinrich Caro at BASF, and in 1905 received the Nobel prize for chemistry, in part for this work.)8 German synthetic indigo destroyed the British monopoly on the main agricultural export - Indigofera tinctoria - of colonial India. In response, British and Indian scientists tried to improve the yield of the natural product. They failed, but their endeavours did contribute to the development of science in India. 

A celebration dinner

Source: Edelstein Collection, Jewish National and University Library, Jerusalem

Celebrations and lessons

In recognition that Perkin's discovery inaugurated the world's first hi-tech industry - the modern, organic chemicals industry - there were various jubilee (1906) and centenary (1956) celebrations around the world. In 1906, the Manchester Courier advised its readers that:  

To England belongs the honour, if Germany is now reaping most of the gain, of the discovery and, to a large extent, the development of the coal tar colour industry. It is now one of the greatest branches of chemical manufacture.9

This statement accompanied the announcement that British chemists and industrialists were about to convene in London to arrange an international celebration, a 'Scientist's Jubilee', to mark the 1856 discovery of the first synthetic, or aniline, dyestuff.  

Arthur G. Green, at Leeds University, was co-organiser with Professor Raphael Meldola, president of the Chemical Society, and chemist John Cannell Cain, of the 1906 jubilee events for mauve in London. Ironically, perhaps, all three had worked at the London dye-making firm of Brooke, Simpson & Spiller that went bankrupt just before the anniversary. The inventions of Meldola and Green were not fully appreciated by the management and, in the absence of patent protection, Meldola's blue and Green's primuline were copied by the Germans to their commercial advantage. This was a hard-earned lesson for the British. Great inventiveness if not properly controlled or developed was soon applied elsewhere.  

Meldola realised what was happening soon after leaving the dyes industry in 1885. On the basis of his own experience and the results of enquiries among textile dyers and printers, who invariably preferred German-made dyes, Meldola lobbied for improved scientific education to reverse, or at least halt, the loss of the world's first science-based industry. 

In Britain, in contrast to Germany, decline followed lack of interest in the benzene ring theory, a slow response to the reform of patent law, and failure to do research by teams of scientists based in dedicated industrial research laboratories. Despite lectures before the Royal Society of Arts, at London and Oxford, letters to leading scientific journals, including Nature, and lobbying spanning two decades, Meldola's message fell on deaf ears. Science teaching and technical education remained in the doldrums. Britain preferred to rely on profits from its colonial enterprises rather than on a science-based industry. 

Fortunately Meldola was a spokesman for science with influential friends who supported the 50th anniversary events. For Meldola, the 1906 jubilee was a celebration of rational human achievement. He was not about to let the matter of loss of British inventiveness spoil the proceedings. Diplomacy drove his speeches at the Royal Institution and a grand dinner in July 1906, events attended by the then ageing and newly knighted Sir William Henry Perkin, a modest man of strong religious convictions who had given generously to Christian charities. Before British and foreign dignitaries and leaders of science and industry, Meldola refused, as one reporter put it, 'to enter into the vexed question of causes' for loss of the dye industry from Britain.  

It took until 1914 before Meldola's warnings were heeded. With the outbreak of World War I in Europe, the dyes industry - the principal producer of aromatic nitro compounds used in the manufacture of explosives, as well as of dyes for uniforms, and coal tar-derived medicinal products for treating the wounded - suddenly became a strategic industry. The problem for Britain was that the country had become dependent on Germany, now an enemy nation, for the supply of many essential aromatic organic chemicals.  

Revival of the ailing dye industry became a matter of urgency. Meldola was co-opted onto government commissions, and devoted his energies to the war effort. He was appointed a member of the Board of Trade Committee on the Supply of Chemical Products, and in 1915 chairman of the advisory council of British Dyes, and of the forerunner of the Department of Scientific and Industrial Research. Exhausted from his exertions, Meldola died late in 1915.  

The RSC celebrates Perkin's purple

To commemorate the 150th anniversary of William Perkin's discovery of the first synthetic dye, mauveine, the Royal Society of Chemistry (RSC) is holding a number of events, including: 

  • in October, two RSC chemical landmark plaques will be unveiled at Greenford and Sudbury in Middlesex, the former to mark the site of Perkin's factory, the latter on the site of the original community centre that Perkin donated to the people of the borough; 
  • a third RSC chemical landmark plaque will be unveiled in November at the former Avecia site at Blakley, Manchester to commemorate the discovery and development of the dyes industry; 
  • web pages on how the discovery of mauveine made such an impact on the fashion and dyes industries, and the development of the chemicals industry, as well information on natural colours and the colour purple.   

Pause for thought

After World War I, the British dyes industry became the first nationalised industry. British Dyes was expanded to form the British Dyestuffs Corporation, which from 1925 became a major part of Imperial Chemical Industries (ICI). Other nations also began to nurture their dyes industries, including the US. The entry into dyes manufacture forced American firms to adopt new strategies based on the German model, including the opening of industrial research laboratories and an emphasis at universities on complex organic chemistry. This led to successes such as novel polymers, including nylon, and, following German and British discoveries, a range of sulfa drugs that were invaluable during World War II.  

For a quarter of a century, commencing in 1945, the US synthetic dyes industry was the world leader, which is why the week-long New York celebrations for the 100th anniversary of the founding of the coal tar dyes industry were the grandest. Across the Atlantic in 1956, Britain had a lot to be proud of when, to mark the centenary of mauve, ICI announced the first of the fibre reactive (Procion) dyes, that form a chemical bond with the fibre.  

The 1960s' Kennedy round of trade negotiations, which led to massive import of textiles into the US, followed by environmental concerns, caused the US dyes industry to decline from around 1980.10 The Europeans followed suit a decade later.  

In 2006, however, there will be little in the way of celebration to mark the 150th anniversary of the discovery of mauve, apart, mainly, from events organised by the Royal Society of Chemistry (RSC). The reasons are partly to do with current perceptions of the dye-making industry: polluting, mature, and hardly practised any more in Europe and North America. The great European dye-makers of the past have moved on to research and development in the life sciences, pharmaceuticals, agricultural products, and polymers, and many have changed their corporate names - that sometimes included the word aniline (such as AGFA and BASF) - in the process. Despite this, Perkin's work should be celebrated as an inspiration for young aspiring chemists. And it is worth taking a moment to consider where one of our greatest preoccupations, modern chemistry and chemical industry, came from. 

Raphael Meldola

Source: Edelstein Collection, Jewish National and University Library, Jerusalem

Raphael Meldola 

Professor Raphael Meldola (1849-1915), president of the Chemical Society during 1905-07, was a charismatic man whose interests went far beyond chemistry. Grandson of the chief rabbi of London's Sephardic Jewish community, he was a man of both religion and science, and proud of both. Educated at the Royal School of Mines, successor to the Royal College of Chemistry, he later undertook spectrum analysis for Edward Frankland at the Royal College of Science. Following Frankland's recommendation to the astronomer Joseph Norman Lockyer, Meldola was placed in charge of the instruments and chemicals required to photograph the total eclipse of the Sun from the Nicobar Islands, east of India, in April 1875. However, the venture failed at the critical moment - heavy clouds masked the Sun. Meldola later wrote a book on photography, and promoted investigations into ancient earthworks, particularly as a prominent member of the Essex Field Club. Meldola, interestingly, became a member of the Royal Society on the basis of his contributions to biology. A close friend of Darwin, he was a keen evolutionist who kept his wife and mother busy during holidays and trips by encouraging them to collect moths.  

Meldola was a capable chemist who worked for a number of years in the British dyes industry, and invented new intermediates and dyes, including Meldola's blue. His first foray into industry (1871-73) was at a firm in West London that later employed Otto Witt who, in the mid-1870s, suggested a theory of colour and constitution and placed colour by design on a firm footing after successfully predicting a then unknown azo dye. The orange dye was introduced by Heinrich Caro at BASF as chrysoidine.  

Meldola encountered a serious problem with his second employer, Brooke, Simpson & Spiller, where he worked during 1877-85. This firm, based in East London, was not interested in filing patents on new inventions that Meldola had made. Disappointed by this cavalier attitude towards discoveries, Meldola decided to go into teaching. In 1885 he was appointed director of the Finsbury Technical College, a junior institution of what later became Imperial College of Science and Technology. 

Contact and Further Information

Tony Travis

Email: Tony Travis