DYES AND TANS
Most vegetable dyes are now superseded by artificial dyes, as aniline, alizarine, and other products of coal tar, etc., but certain kinds are still of some commercial importance and are generally considered more permanent than the latter.
Vegetable dye stuffs owe their origin to the presence of small quantities of certain chemical substances secreted in the plant tissues which are extracted by processes of fermentation, boiling, or chemical treatment.
Tannin, closely related to dye-stuffs, often occurs in plants as an excretum in the bark and other parts, which are either employed direct, or used for the extraction of the substance in a concentrated form. Tan stuffs are also often used for dyeing or staining as well as for tanning purposes.
The fruits are collected when nearly ripe, and as the shells dry they burst open, the seeds being then either pressed and made into " annatto paste," or merely dried with their covering and then marketed as " annatto seed." Formerly the paste form was preferred by manufacturers, but the demand for this has now declined in favour of the dried "seed." The dye, however, is very fugitive.
Annatto seed is exported from Trop. America, chiefly to the United States and England, and commands about 1 shilling. per lb. In Ceylon, small plantations of Annatto were made about 1890�95, chiefly in the Matale district, and the product was until recently an article of export. It has now, however, disappeared from the Island's exports, but the dye is sometimes used locally by the peasants, as for colouring cacao beans.
The tree is readily propagated from seed, and the plants may be spaced 18 x 15 ft. A small crop may be obtained after the third year from planting, the yield from mature trees being about 5 cwt. seed per acre. Two or more varieties occur in Ceylon.
Cochineal consists of the dried bodies of woolly insects, commonly known as "bugs" (Coccus cacti), which live on species of Opuntia or Nopalea, chiefly N. coccinellifera or Spineless Cactus (q.v.). The insect occurs in two varieties, viz. "silver cochineal," which has a grayish red colour, the furrows of the insect body being covered with a white down; and "black cochineal," which is of a dark reddish-brown and is destitute of down. The former is the more valuable. The male insect is winged, but the female is wingless and when full-grown is of the size of a rice grain. It is the latter which forms the cochineal of commerce, to produce a pound of which some 70,000 insects are required.
The insects are gathered three times a year; they are carefully brushed from the Cactus into bags, killed by immersion in boiling water, and then dried in the sun or over a fire. The dried insects keep in good condition for many years. Cochineal was formerly of considerable importance, being valued for dyeing silk and for colouring butter and cheese. It produces beautiful scarlet shades, but is now mostly superseded by aniline dyes, its chief use being for artists' paints. Originally a Mexican industry, it has been introduced into Brazil, Java, Canary Islands etc the last-mentioned country still doing a considerable trade in it. Europe alone takes some 1 million pounds of cochineal annually, the price ranging about 3s. per lb. Formerly it fetched from 6s. to 9s. per lb.
Cutch or Catechu; Khair or Katha of India. (Acacia Catechu.) A medium sized tree, common in parts of India, Burma, etc. A black gum-resin known as Cutch or Catechu, obtained by boiling chips of the heart-wood, is astringent and extensively employed for dyeing and tanning, being largely exported. It is estimated one ton of the heart-wood yields on an average 250 to 300 lb. of cutch. A form of cutch is commonly used in India for chewing with "betel" leaf (q.v.), and a valuable gum, resembling gum arabic, is also obtained from it, while the wood is one of the best for charcoal. The term "cutch" is applied to a similar extract from Gambier (q.v.).
Dragon's Blood. A resinous incrustation obtained from the scaly covering of the fruits of Daemonorops propinquus, a climbing palm of the Rattan family (q.v.), collected chiefly in Borneo, Sumatra, Malaya, etc. The small, round fruits, about � in. diameter., are dried, then shaken in a basket, through which the resin falls; it is collected on a cloth damped in hot water, and pressed into moulds. "Singapore Lump " dragon's blood is now quoted at about �27 per cwt. Similar substances, known by the name of Dragon's Blood, are obtained from Dracaena Draco in the Canary Islands, Dracaena Cinnabari in Socotra and Zanzibar, and Croton Draco in Mexico. The chief use of the product is for colouring varnishes.
Henna ; Tree Mignonette; Maruthondi, T'. (Lawsonia inermis. Lythraceae.) A shrub 6 - 8 ft. high, widely distributed in the drier parts of N. and E. Tropical Africa, Madagascar, Trop. Asia (including Ceylon) and Australia. It is often cultivated in hedges and as a dye plant, especially in India, Persia, Egypt, etc. The small oval leaves, powdered and made into a paste, give the Henna dye, which is commonly used, especially by Mohammedans, for dyeing the hair, nails, beard and skin a dull orange-yellow. The leaves are exported to Europe for use in cosmetics and similar purposes. At each clipping of the plants, about 8 or 9 in. are taken off the young shoots, the annual yield being about 1,600 lb. of dried leaves, etc., per acre. In Europe, Henna is often mixed with the flower-heads of Chamomile (Anthemis nobilis). Indian henna leaves now quoted in London at 45s. per cwt.
Indigo. Nil - awari, S. A blue dye obtained from species of
Indigo fera (Leguminosae), chiefly I. arrecta and
During the Great War, however, indigo received a fresh impetus, the price advancing in one year from �17 to �67. This and other vegetable dyes are, however, considered to have certain advantages over aniline dyes, being " softer " and more permanent, e.g., the famous Persian rugs and carpets in which natural dyes are used.
Cultivation. The plant requires a hot and moist climate (rainfall not under 70 - 80 in.) and well-drained, light friable soil. Thorough tillage is necessary. The seed is sown in lines about 2 ft. apart, 12 -15 lb. being required to the acre. The seed germinates in 3 or 4 days, and about 3 months later the flowers appear, when the plants are ready for harvesting. The crop is usually cut down to within about 6 in. from the ground, tied up in bundles, and carried fresh to the factory. The stumps left in the ground will afterwards "rattoon," and two, or in favourable conditions as many as four, rattoon crops may be obtained from the same roots within the year. The plant is best grown in rotation with other crops.
To produce the dye, the green crop is placed in large masonry tanks and weighted down with planks. Water is laid on so as to cover the whole, which is subjected to a process of fermentation and churning. Fermentation is allowed to go on for 12-16 hrs., and stopped when the leaves become a pale colour. The liquid is run off by means of a tap at the bottom of the tank, into a second tank or cistern, and is kept constantly agitated by either wading coolies beating with paddles, or by a mechanical contrivance, for 2 or 3 hrs., after which the indigo settles in the bottom in the form of bluish mud. This, after draining off the water, is put into bags which are hung to dry, being afterwards cut into cubes about 3 in. square, stamped, and further dried for export.
Yield. A good yield should be about 12,000 lb. of green crop per acre from the first cutting, giving 60 lb. dry indigo. Subsequent or rattoon crops give smaller yields. About 35 - 40 lb. of indigo paste may be obtained from 1,000 lb. of green plant, and 500 lb. of paste per acre is considered a good average annual yield. Normally, indigo fetches about 2s. 6d. - 3s. 3d. per lb. in England.
Chinese Indigo is obtained from Polygonum tinctorium, a large herbaceous perennial, commonly cultivated in China and Japan, and known in Korea as "Tjok" Yoruba Indigo, see Lonchocarpus.
Logwood. (Haematoxylon campechianum. Leguminosae.) A small, slow growing tree, about 20 ft. high, native of Cent. America introduced and naturalised in Jamaica and other W. Indian islands. The heart wood as well as the roots are exported for the extraction of a valuable fast dye (violet, dark blue, or purple), which is used in the manufacture of ink and in dyeing woollen and silk goods, and for numerous other purposes. Introduced to Ceylon in 1845. The tree thrives naturally in a hot and rather dry climate, a moist atmosphere and rich, heavy soil being unfavourable to the development of the dye.
In cultivation, care should be taken to select the red-wood kind, the "bastard" or colourless sort being of no value. Propagation is by seed. Seedlings may be planted out 12 X 12 ft. apart, or about 300 to the acre. Little attention is necessary, beyond weeding, after the plants are well established. From the age of 10-12 years the trees are ready for felling; the sap-wood, being valueless, is chipped off and discarded, and the brownish red heartwood is made up in bales for export, being usually valued at about �3 - �6 per ton, and the roots about �2. In Jamaica it is used to some extent for the extraction of the dye locally. British Honduras, where the tree is indigenous, is the principal exporting country.
Orchella. (Rocella Montaguei.) A pale, greenish grey lichen, with flaccid, ribbon like fronds, found growing on rocks or old tree trunks, chiefly in drier districts close to the sea coast. The lichen was formerly collected in Ceylon and, being dried and made up in bales, exported for the purpose of extracting the dyes litmus, orchil, etc. It was valued at about 15s. - 20s. per cwt.
Saffron. (Crocus sativus. Irideae.) Small, showy bulbous plant of the Iris family, 6 -10 in. high, native of S. Europe, cultivated in Spain, S. France, Turkey, Persia, Kashmir and China for the sake of the orange-coloured stigmas of the flowers. From these the true saffron of commerce, used as a colouring agent, is obtained. This is employed in India chiefly for princely marriages and for caste markings of the wealthy. Its cultivation dates back to remote antiquity, and at one time was much used in medicine. It requires a warm or sub-tropical climate and a rich, well drained garden soil. It is propagated from bulbs (corms), which when once established may be left in the ground undisturbed for 10 -15 years or more.
During the blossoming period (October-December in Kashmir) the
flowers are collected daily, just as they open. The stigmas are then
removed by hand and dried immediately, usually in a fine sieve over a
low fire. When fully dried, they are at once packed or stored. The yield
is variously estimated at from 10 to 30 lb. per acre. About 40,000
flowers are required to produce a pound of dry saffron, which
consequently is very expensive, being valued at from about
Safflower, or False Saffron; Kasum or Kurdi of India. (Carthamus tinctorius. Compositae.) A prickly, herbaceous plant, 2 - 4 ft. high, supposed to be indigenous to India; cultivated in Egypt, China, India, Persia, Spain, etc., for the orange yellow florets of the aster like flowers, which are used as a dye. These are collected fresh in the morning, dried in the shade on muslin trays, and afterwards stored in tins. In India the crop is sown in October or November and harvested in January-April. It thrives in a light, well-tilled, sandy soil. Seed is sown broadcast or in drills (spacing about 18 x 22 in.) at the rate of about 6 lb. to the acre. The yield of florets should be about 80 lb. per acre. The red colouring matter (carthamin) is valued for dyeing silk, cotton, etc. Safflower was at one time largely exported from N. India and Persia to Europe. The chief use of the plant now is for the oil from the seed, esteemed for cooking, etc. Yield of seed per acre about 500 lb. or 10 bushels.
Sappan wood. Bakam, Tairi, or Patang of India; Pattangi, S. (Caesalpinia Sappan. Leguminosae.) A large, straggling, prickly, semi-climbing shrub, native of India and Malaya, naturalised in the moist low-country of Ceylon. The dark red heartwood yields a red dye and is exported, chiefly from Siam and the Philippines, after removal of the sapwood, for the extraction of the dye. Some 900 cwt. of Sappan wood is exported from Ceylon annually, valued at about 9s. per cwt. The dye is used for dyeing wool, calico, etc. The plant grows in clumps, producing several stems, which take about 6 years or more to produce a marketable heartwood, and requires no cultivation. As the older stems are removed, others grow up and take their place. Seed season, August - November. The plant, woven by itself or between trees, forms a good barrier hedge. It was once known as Brazil Wood, which properly belongs to G. echinata of S. America, on account of which the country Brazil takes its name.