Perkin , Sir William Henry

(1838–1907) British chemist

Perkin was born in London, the youngest son of a builder. His interest in chemistry was aroused early by some experiments shown to him by a young friend and he was fortunate to attend the City of London School, which was one of the few London schools where science was taught. Perkin's teacher there, Thomas Hall, was a pupil of Johann Hofmann at the Royal College of Chemistry and Hall pleaded with Perkin's father to allow his son to study chemistry and not to force him into a career in architecture. Hall was successful and Perkin entered the college in 1853.

In 1855 he was made Hofmann's assistant and the following year was given the task of synthesizing quinine (despite much effort, this difficult task was not achieved until 1944, by Robert Burns Woodward and William von Eggers Doering). Perkin started from the coal-tar derivative allyltoluidine, which has a formula very similar to that of quinine. He thought the conversion could be achieved by removing two hydrogen atoms and adding two of oxygen. Although no quinine was formed by this reaction, it did produce a reddish-brown precipitate. Perkin decided to treat a more simple base in the same manner and tried aniline and potassium dichromate. This time a black precipitate was produced. Addition of alcohol to this precipitate yielded a rich purple color. Perkin soon realized that this coloring matter had the properties of a dye and resisted the action of light very well. He sent some specimens of dyed silk to a dyeing firm in Perth, Scotland, which expressed great interest provided that the cost of the cloth would not be raised unduly. With this behind him, Perkin took out the appropriate patents, borrowed his father's life savings, and in 1857 built a dye factory at Greenford Green, near Harrow, for mass production of the first synthetic dye – mauveine.

Initially there were difficulties. Since aniline was not readily available, it had to be produced at the factory from benzene. There was also the conservatism of the dye industry to overcome.

The significance of Perkin's discovery lay in its being the firstsynthetic dye; before this all dyes were derived from such organic sources as insects, plants, and mollusks. Purple had traditionally come from a Mediterranean shellfish and could be produced only at great cost, so that it was used only by royalty. Apart from the difficulty of supply there was also the problem of the quality of the dyes: vegetable and animal dyes were not particularly fast and tended to fade in the light. The market was ripe for anyone who could provide a dye in bulk that was cheap, fast, and did not fade. Perkin quickly made his fortune and stimulated a rush to find other synthetics. Carl Graebe and C.T. Liebermann soon synthesized alizarin, the coloring ingredient of madder. Magenta and Bismarck brown were among the other new colors that were soon to flood the market.

In 1874 Perkin sold his factory and retired, a wealthy man, at the age of 35, devoting the rest of his life to research in pure science. He became particularly interested in Faraday rotation and produced over 40 papers on this topic.

Perkin was knighted in 1906. His son and namesake was also a chemist.