Indigo

 

India was a primary supplier of indigo to Europe as early as the Greco-Roman era. The association of India with indigo is reflected in the Greek word for the dye, indikón (Ἰνδικόν, Indian). The Romans latinised the term to indicum, which passed into Italian Dialect and eventually into English as the word indigo.

The demand for indigo in the 19th century is indicated by the fact that in 1897, 7,000 km² (2,700 sq mi) were dedicated to the cultivation of indican-producing plants, mainly in India. By comparison, the country of Luxembourg is 2,586 km² (998 sq mi)

In 1865 the German chemist Adolf von Baeyer began working on the synthesis of indigo. He described his first synthesis of indigo in 1878 (from isatin) and a second synthesis in 1880. It was not until 1883 that Baeyer finally determined the structure of indigo.

Indigo Dye Uses 

Snapshot

The use of indigo for dyeing textiles was most popular in England, and was used to dye clothing worn by men and women of all social backgrounds. Natural indigo was replaced in 1880, when synthetic indigo was developed. This pigment is still used today to dye blue jeans. However, over the last decade scientists have discovered that the bacteria Escherichia coli can be bio-engineered to produce the same chemical reaction that makes indigo in plants. This method, called “bio-indigo,” will likely play a big part in manufacturing environmentally friendly denim in the future.

Fun fact: Sir Isaac Newton—the inventor of the “color spectrum”—believed that the rainbow should consist of seven distinct colors to match the seven days of the week, the seven known planets, and the seven notes in the musical scale. Newton championed indigo, along with orange, even though many other contemporary scientists believed the rainbow only had five colors.