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 manoeuvre.
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]