WILLIAM PERKIN

A Number of important discoveries have been made by accident. Many experiments must have been discarded when they went wrong, but a few apparent failures have become the starting points for major advances. Anyone can make a mistake, but it takes an exceptional mind to realize the full significance of an unusual result and to develop it successfully.

It was in such circumstances that the young William Perkin made the first synthetic dye in 1856. At the time he was still a student, but so great was the enthusiasm for chemistry that he had a small laboratory at his home.

One day he set out to make  the drug quinine by the action of an oxidizing agent on allyl toluidine, an aromatic compound with an amino (-NH2) group attached to the benzene ring. It is not really surprising that he did not succeed since it is now known that these two compounds are not related structurally.

Although he failed to synthesize quinine, William Perkin did obtain a red-brown precipitate. He was sufficiently interested in this product to repeat the experiment using a simpler aromatic amine. He obtained a black precipitate by the action of potassium dichromate (a powerful oxidizing agent) on aniline sulphate. From the precipitate he separated a small quantity of a mauve substance which he examined further. It had all the properties of a dye and, of even greater importance, it was unaffected by strong sunlight (At that time almost all dyes were of animal or vegetable origin and no mauve dye was ‘fast’ to sunlight)

Several dyers became interested in his discovery so he set out to make this mauve dye in commercial quantities. He was fortunate in having the assistance of his father and brother in this venture and in June 1857 work started on the erection of a factory at Greenford in Middlesex. While the building operation continued, William Perkin was busy ‘scaling-up’ his process.

Thus, at the age of nineteen he had laid the foundation of a whole new industry – the coal-tar dye industry, so named because the raw materials are extracted from coal-tar. William Perkin continued his experiments in search of other dyes and by 1869 had developed the first commercial process for making artificial alizarin, a red dye, had previously been extracted from the root of a pant Rubia tinctorum.

William Henry Perkin was born in London in 1838. He was a pupil at the City of London School before he entered the Royal College of Chemistry in 1853 to study under August Wilhelm von Hofmann.

The dye making business was so successful that William Perkin was able to sell the factory in 1874, so that he could devote all his time to research. As well as synthesizing a number of dyes, he developed a method of making unsaturated aromatic acids (i.e. aromatic acids with a double bond in the side chain). He was also the first person to synthesize the perfume coumarin.

William Perkin was awarded both the Royal and the Davy Medals of the Royal Society. Shortly before his death in 1907, he was knighted.

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