The author mentioned that an Englishman, William Perkins, accidently discovered an artificial dye but Britian did not capitalize on this discovery. As a consequence Britain lost out on being a leader in which important 20th century technology?

The pharmaceutical industry

Explanation:

While attempting to produce quinine, the young William Henry Perkin discovered mauve, the first synthetic dye. He then found that the yellow dye flavine killed the germs responsible for abscesses; this led to the development of a wide range of useful drugs, all derived from chemicals found in coal tar.