India indigo

As early as 2500 bce m India indigo was used to dye cloth a deep blue The early Phoenicians discovered that a purple dye of great value Tyrian purple could be extracted from a Mediterranean sea snail The beauty of the color and its scarcity made purple the color of royalty The availability of dyestuffs underwent an abrupt change m 1856 when William Henry Perkin an 18 year old student accidentally discovered a simple way to prepare a deep purple dye which he called mauveme from extracts of coal tar This led to a search for other synthetic dyes and forged a permanent link between industry and chemical research... 

Indigo was originally made from two plants. One is woad, Isatis tinctoria, a native of Greece and Italy, and the other is indigo, Indigofera tinctoria, a native of India. At the end of the nineteenth century, German scientists synthesized the dye, and production from plant sources declined. Most of the dye today comes from China. 

The natural dyes industry was also a large, sophisticated, and worldwide employer. Master dyers made a wide range of reasonably fast colors and handed down secret dye recipes to their apprentices. Europe s two staple dyes were madder red from the Mediterranean and indigo blue from India. Other natural dyes included violet from lichens dark red from the forget-me-not family brown from African aloe plants and black from tumorlike... 

It is employed by the natives of North-wcstom India for precipitating their indigo, and in tanning. English tanners, however, object to its use on account of the disagreeable color it communicates to the leather. 

Indicum, mentioned by Vitruvius and described by Pliny and Dioscorides as a production of India, being a slime which adheres to certain reeds there, is our indigo. When... 

As both Vitruvius and Pliny have described under the same name indicum, the blue or purple indigo, this black indicum is doubtless India ink, known to have been made in China before our era. It is also probable that the ancients in Europe did not know whether the black and the blue indicum were of essentially different origin or not. As a matter of fact, the India ink also has lampblack as its base. 

Blue materials used as pigments or dyes, were the lapis lazuli (ultramarine), azurite (armenium). Both of these sometimes were called caeruleum. Indicum was indigo imported from India. Purpurissium was the name given to a pigment made from chalk colored with a purple dye, but whether from murex, indigo or woad does not seem definitely stated. 

Mix black indikon (indigo—or India ink ) with resin and heat the crystal. If you let it cool in the mixture, it will become excellent beryl. 

In the period 1700 to 1900, the production of what came to be known as natural indigo was carried out on a very large scale. The indigo plant was cultivated in enormous plantations, chiefly in India and the countries of South-East Asia and America. As much as one square kilometer was needed to obtain a tonne of indigo a year [2], The reason for such a high land requirement was simply that the plant material contains barely 1 % of the dye s precursor indican, the rest being biomass. 

Towards organic substances ozone is strikingly active. Organic colouring matters are bleached for example, indigo is oxidised to isatin.8 Turpentine rapidly absorbs the gas, and if the hquid is exposed on filter paper in an atmosphere of ozone, inflammation may occur.9 India-rubber is rapidly attacked and so is of little value for connections... 

The blue dye indigo, derived from the plant Indigofera tinctoria, has been used in India for thousands of years. Traders introduced it to the Mediterranean area and then to Europe. Tyrian purple, a natural dark purple dye obtained from the mucous gland of a Mediterranean snail of the genus Murex, was a symbol of royalty before the collapse of the Roman empire. Alizarin, a bright red dye obtained from madder root Rubia tinctorum), a plant native to India and northeastern Asia, has been found in cloth entombed with Egyptian mummies. 

The increase in the production of the synthetic indigo has decreased the cultivation of the indigo plant, especially in India where the land formerly used for this purpose is now used for other crops such as rubber, turmeric, hemp, cotton, etc. 

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