Natural food colourings, such as spinach, saffron and beetroot, have been used for thousands of years. But a synthetic organic dye called mauveine, also known as aniline purple, was accidentally created by British chemist William Henry Perkin in 1856 when he was trying to synthesise a medicine for malaria. The synthesis yielded a ‘failed’ black solution, but when he cleaned the flask with alcohol, he noticed a vivid, purple compound. The dye was being used in clothes and drugs as a cheaper alternative to natural dye by the early 20th century, and as a food colouring as well, until the chemical was linked to certain types of cancer.