sentences:  By 1804, the English dye maker George Field had introduced new techniques known as "lake" madder, that extended the use of the tincture to paints.Robiquet obtained from madder root two distinct molecules with dye properties, the one producing a magnificent red, that he called alizarin, which proved as well extremely stable, and another, of less stable properties, that he called purpurin.Some 30 years later in April 1856, William Henry Perkin, then a mere youngster working as assistant at the Royal College of Chemistry in London within a team intent on research over the synthesis of quinine, a potent drug, discovered a process that obtained a purple dye (which he called mauveine) from aniline, which in turn could be easily obtained from coal tar; over the next ten years Perkin set up the first industrial model of molecules obtained through synthesis from coal tar and his success had prompted intense research from numerous teams all over Europe on coal tar by-products, while he himself pursued such a work on top of his industrial activity.