For most of recorded history purple was the color you could not buy. It signaled rank because the dye cost more than the cloth it colored. Kings guarded it, and laws in some places made it a crime for common people to wear it. Then in one stretch of years the price collapsed, and shop girls in London wore the same shade as the queen. The cause was not a fashion movement or a new trade route. It was an eighteen year old chemist who was trying to make a malaria drug and failed. His failure is the reason color is cheap today.
The old purple came from sea snails. Dyers along the eastern Mediterranean crushed murex snails, let the glands rot in the sun, and boiled the sludge for days. The yield was tiny. Modern estimates put it near ten thousand snails for a single gram of dye. The smell of the dye works was so bad that Roman law pushed the shops to the edge of town. Tyrian purple held its color instead of fading, which made it worth the cost to anyone who could pay. Roman emperors reserved it for themselves, and the phrase born to the purple came out of that rule.
William Henry Perkin was a student at the Royal College of Chemistry in London. His teacher, August Wilhelm Hofmann, wanted someone to build quinine in a lab. Quinine treated malaria, it came only from cinchona bark, and Britain needed a great deal of it for troops overseas. Perkin took the problem home over the Easter break in 1856 and worked in a rough lab on the top floor of his house. He started with aniline, a cheap byproduct of coal tar, which was the black waste left over from making gas for street lamps. He mixed it with an oxidizer and hoped for quinine. He got a black sludge instead.
Most students would have washed the flask and moved on. Perkin rinsed his with alcohol, and the sludge gave up a deep purple solution. He dipped silk in it and the silk took the color. Then he ran the test that mattered. He left the dyed silk in sunlight and washed it, and the purple stayed. Natural dyes of the day faded fast, so a color that held was worth real money. He sent a sample to a dye works in Perth, and the reply told him he had something. He was still a teenager, and he decided to quit school and sell it.
He filed a patent in August 1856, weeks after his nineteenth birthday. His father put up the family savings and his brother joined him, and they built a plant at Greenford Green outside London. Nothing about it was simple. He had to make his own aniline because nobody sold it at scale, and he had to design equipment that did not exist yet. He also had to teach dyers how to handle a dye that behaved unlike anything in their shops. The first orders were small and the early losses were real. Within three years the business turned a profit.
The color caught on because two women wore it. Empress Eugenie of France liked how it matched her eyes, and Queen Victoria wore mauve to her daughter's wedding in 1858. Demand ran ahead of supply, and the price of purple cloth fell every season after that. In 1859 the magazine Punch joked that London had caught the mauve measles. Working people bought ribbons and shawls in a shade that had been off limits for two thousand years. That shift is easy to miss now, because we assume any color can be had for a few dollars. It could not, and the whole change happened inside one man's lifetime.
The bigger result was an industry. Chemists across Europe saw that coal tar held a fortune and started pulling new colors out of it, and German firms took the lead. BASF, Bayer, and Hoechst all began as dye makers. The lab skills they built for color turned out to work on drugs, because the same ring structures sat at the heart of both. Bayer sold aspirin in 1899 out of a business that started with dye. The chemical giants of the twentieth century grew from a purple that nobody set out to make.
Medicine gained something else. Aniline dyes stained tissue and bacteria in ways older stains could not, so scientists could finally see what they were studying. Robert Koch used them to identify the bacteria behind tuberculosis. Paul Ehrlich noticed that certain dyes stuck to some cells and ignored others, and that observation led him to hunt for a drug that would attack a disease and leave the patient alone. That idea became the foundation of chemotherapy. None of it was the plan. A student wanted a malaria cure, made a mess, and rinsed the flask instead of scrubbing it clean.
