Indigo plant
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Inflorescences and leaves of an indigo plant ( Indigofera tinctoria ) |
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| Indigofera tinctoria | ||||||||||||
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The tropical indigo plant Indigofera tinctoria belongs to the legume family (Fabaceae). The homeland of the indigo is - apart from India - in tropical Africa and in China .
description
The indigo plant bears odd- pinnate leaves. The leaflets are elliptical and have entire margins . The red butterfly blossoms are in clusters at the branch tips.
The number of chromosomes is 2n = 16.
use
The Indigofera is primarily used to extract indigo , a valuable dye from which the color indigo , a deep blue on the border with violet, takes its name.
The leaves of the indigo plant contain indican in a concentration of 0.2-0.8%. This colorless and water-soluble derivative of the amino acid tryptophan is the precursor of indigo, which was obtained as follows:
- The harvested leaves were watered so that the indican glucose was split off ( hydrolysis ).
- Naturally present enzymes ensured that the indican was broken down into yellow indoxyl within about ten days ( fermentation ).
- The fermentation product combined with the oxygen in the air to form the blue indigo dye ( oxidation ), which flocculated.
- The precipitate was mixed with a strong base such as sodium hydroxide solution ( alkalization ), pressed into cakes, dried and finally pulverized.
Today the indigo dye is produced synthetically.
The dried, ground leaves of indigo plants are also used for hair coloring. This is how you get a dark brown to black color. They are also mixed with other plants such as henna ("black henna").
Cultural history of indigo
The cultivation of the indigo shrub comes from the countries of origin in India and East Asia and is already 2500 BC. Can be proven in Egypt. Pliny describes the origin from India. The dye occurs in the foam of the rivers and is deposited on a certain type of reed from which the locals collected it. Indigo was rare in Europe until the 12th century; it was imported in small quantities from India via Syria and Alexandria . Around 1420 it is listed on a Venetian freight list. From 1600 he has been in large quantities by the Dutch in the East Indies introduced and displaced the hitherto used for dyeing of textiles woad .
Beroai is a Japanese term for imported indigo . Beroai was particularly popular in the Bunsei (1818-1830) and the subsequent Tenpō period (1830-1844). An example is 36 views of Mount Fuji by Katsushika Hokusai from the Tenpō period.
In 1878 Adolf von Baeyer succeeded in fully synthetic production of indigo for the first time . Synthetic indigo has been sold commercially since 1897 and has almost completely supplanted indigo production from vegetable raw materials.
Cultivation
India
Indigo cultivation in India has been documented since ancient times. The plant is called Nila in Sanskrit (Nile in Hindi).
In the middle of the 19th century, European capitalists ("planters") in British India began to acquire cultivation rights in the area of permanent settlement from the local large landowners ( zamindar ) by means of so-called Tinkathia leases and to grant the farmers ( raiyat ) to them undertake to cultivate 3 / 20th of their best land with the indigo plant. The farmers had to accept interest-bearing advances through middlemen for the purchase of the seeds, with fraudulent contracts and interest rates of 50–500% being common. However, the tenants did not receive a guaranteed price, but a price fixed at harvest time, which was below market value. Another problem was that indigo could not be integrated into the regular crop rotation. The dye was processed in local factories. When the sale of indigo was no longer profitable for the planters ( thikadari ) and their middlemen, they demanded “ redemption ” ( tawan ) and lease surcharges ( sharahbeshi ) from the farmers . The exploitative practices led to the so-called indigo riots in 1859–1862 . The last remnants of the Tinkathia were not abolished until 1917/18 after the Champaran campaign (northeastern Bihar) Mohandas Gandhi .
United States
Overview
On the territory of what is now the United States , the first attempts to cultivate indigo were made as early as the mid-17th century. However, indigo cultivation only became commercially successful in the British colonies after Elizabeth Lucas Pinckney (1722–1793) introduced the plant to South Carolina in 1739 . After a series of unsuccessful attempts, in 1747 she succeeded for the first time in producing enough indigo for a shipment to Great Britain, where climatic conditions do not allow the plant to be grown. From then on, indigo from South Carolina was in high demand in the kingdom, so that it became one of the colony's main agricultural products. Production reached its peak in 1773.
When the British export market ceased during the Revolutionary War , indigo cultivation in South Carolina was replaced by rice cultivation. After the end of the war, the American indigo could no longer hold its own against the cheaper and better indigo from India. By the end of the 18th century, cotton became the main agricultural product in South Carolina, displacing indigo even further.
Indigo was also grown on a small scale in Georgia and Louisiana . In Louisiana the plant was cultivated by the French since 1718; By 1763, indigo had become the most important export product there, but at the end of the 18th century it was replaced by more profitable agricultural products such as cotton, sugar cane and tobacco. In Florida Indigo was introduced in the 17th century by the Spanish.
Indigo cultivation and slavery
Growing indigo required a lot of manual labor, but not quite as much as growing sugar cane or rice . The sowing (April) was followed by a first cut on the North American mainland in early July and often a second cut in late August. The chores involved in growing indigo included preparing, plowing , hoeing and leveling the fields, sowing , pulling weeds and plowing again to aerate the soil. After the cut , which takes place shortly before flowering, the plant had to be cut into pieces, bundled and processed on the same day. Further processing comprised watering in tubs or vats, where the dye was released from the plant and, as a result of a fermentation process, acquired the desired blue color. At this stage the processing of the indigo was particularly disgusting; the stinking (and in the opinion of many contemporaries harmful) brew had to be pounded incessantly for hours after it had been poured off from the rest of the plant so that the dye separated from the water and precipitated in flakes on the bottom of the tub. After the water had been poured off, the dye, which now had a pudding-like consistency, was spooned into cloth sacks in order to continue to lose water overnight. The next day the mass was poured into molds, pressed again and dried, and finally cut into cubes.
Slaves worked on the indigo plantations of the North American colonies from the start . The Spaniards had initially used Indian slaves to cultivate indigo , but then came to the conclusion that the diseases from which they died in large numbers were caused by the processing of indigo. The Indians were then replaced by slaves imported directly from Africa. African-born slaves also worked on the indigo plantations in the French and British colonies. Since the European colonial masters had little experience with the plant, the expertise of these slaves, who were often familiar with indigo cultivation from Africa, made a significant contribution to the rise of American indigo production. Unlike in many other areas of work, the slaves on the indigo plantations in South Carolina and Georgia were employed according to the task system , i.e. In other words, they did not work a certain number of hours in the column ( gang system ) under an overseer , but were given defined tasks for each day, which gave them a certain power of disposal over their time, which they also had to manage their supply gardens and fields required. The cultivation and processing cycles of indigo and rice made it possible to have both plants cultivated by the same slaves at the same time.
literature
- David Patrick Geggus: Indigo and Slavery in Saint Domingue. In: Verene A. Shepherd (Ed.): Slavery without Sugar. Diversity in Caribbean Economy and Society since the 17th Century . Gainesville, 2002, p. 1935.
- Carlos O. Stoetzer: The Central American Indigo and its echo in the early modern period. In: Yearbook for the History of the State, Economy and Society of Latin America. 32/1995, pp. 123-146.
- David L. Coon: Eliza Lucas Pinckney and the Reintroduction of Indigo Culture in South Carolina. In: The Journal of Southern History. 42, 1/1976, pp. 61-76.
- Fritz Lauterbach: The fight of the woad with the indigo . Leipzig 1905.
- Elie Monnereau: Le parfait Indigotier ou description de l'indigo… Amsterdam 1765.
Individual evidence
- ↑ Indigofera tinctoria at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ^ Engraving from the Histoire générale des Antilles by Jean-Baptiste du Tertre (1667)
- ↑ a b Robin JH Clark, Christopher J. Cooksey, Marcus AM Daniels, Robert Withnall: indigo, woad, and Tyrian Purple: important vat dyes from antiquity to the present. In: Endeavor. NS 17/4, 1993, 192 (Pergamon Press) ISSN 0160-9327 .
- ^ J. Crawfurd: On the History and Migration of Textile and Tinctorial Plants in Reference to Ethnology. In: Transactions of the Ethnological Society of London. 7 (1869), pp. 1-15.
- ↑ a b A Brief History of Indigo in the United States ( Memento of the original dated November 5, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. ; The Devil's Blue Dye: Indigo and Slavery ( Memento of the original from June 14, 2012 in the web archive archive.today ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ A Brief History of Indigo in the United States ( Memento of the original dated November 5, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ A b The Devil's Blue Dye: Indigo and Slavery. ( Memento of the original from June 14, 2012 in the web archive archive.today ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
