The Blue Dye Plant.

The Living Age 57, 29.5.1858

From Household Words.

The indigo plant is a beautiful, bright green grass, or shrub; and is called a biennial, because it passes though all the phases of its existence in two years. Its leaves consist generally of collection of leaflets arranged, alternately, one above the other upon each side of the petiole or leaf-stalk. At the base of the leaf-stalk, but separated from it, are two leaflets called stipules, which are distinguishable from the others by having no median nervure or vein down the middle. In the Monocotyledonic plants, or plants with one primordial leaf, such as the palm-trees, the stipules form the sheaf, - a kind of living cradle provided by Nature for the protection of the leaves during their tender infancy.

The bright-red flowers of the indigo plant, which are all assembled together at the summit of the peduncules or flower-stalks, present the appearence, like the sweet-pea in blossom, of a butterfly; for this reason all the plants of this class are called papilionaceous, from the Latin papilio, - a butterfly. The shapes of the petals or flower-leaves, which to the number of five compose this blossom, are so peculiar that each of them has received a distinct name. Thus the large upper one, which turns backwards, is called the standard or flag; the two next, which are both alike and placed one on each side, are the wings; the lower one between the wings is the boat or keel, and is composed of one or two hollow flower-leaves, holding the stamens and the pistil, and sheltering them from the rain. In the indigo plant the wings are sometimes joined together in the form of carina, ear or bark.

All the butterfly plants, including the indigo, have the habit of spreading out their wings in the day and folding them up at night. Linnæus discovered this fact in an interesting way: A friend having sent him some seeds of a butterfly-plant, he sowed them in his green-house where they soon produced two beautiful flowers. His gardener having been absent when he forst observed them, Linnæus went with a lantern in the evening t o show them to him. But to his surprise they were nowwhere to be found, and Linnæus was obliged to content himself by supposing that they had been destroyed by some accident or by insects. Great, however, was his astonishment next morning at finding his blossoms exactly where they had been the day before. Accordingly he took his gardener again in the evening to see them, and again they could bot be found. Finding them once more, the following morning, looking as fresh as ever, his gardener said: "These cannot be the same flowers, they must have blown since." But LinnæMus himself, not being so easily satisfied, re-visited the plant as soon as it was dark, and, lifting up the leaves one by one, found the flowers folded under them, and so closely concealed as to be completely invisible at first sight. Led by this incident to observe other plants of the butterfly tribe, he found that they all, more or less, closed their wings at nightfall; and this fact formed the basis of his theory of the Sleep of Plants.

The seed-vessel of the indigo plant is like that of the common pea. Once sown in a loose and dark soil, the indigo plant requires no further care, until the time comes for cutting it. As the rainy season aapproaches, and the red butterfly blossoms begin to appear, the planter hastens to have it cut, for fear of the dye being washed away or spoilt by the inundations. In the moth of July, parties of Hindus may be seen in the indigo plantations in the upper provinces, clipping the bright green leaves and twigs to the level of the ground, followed by others who, picking up the plants as they are cut, bind them together and load them upon carts, while the planter passes through the fields, wearing a hat with a brim nearly as large as an umbrella, covered with white cloth, and comfortably perched in a dounsh or car on the back of a huge elephant, whose neck is bestrode by a native mahout or driver armed with an iron rod.

From the fields of the indigo is taken into a building called a vat, which is about thirty feet broad, and forty feet long. There are steps outside, leading to a platform within the building, from which a sort of immense bath is seen filled with the plant. Water being then let in from a reservoir, the indigo is allowed to ferment for about fourteen or sixteen hours. At the end of that time, the plant becoming entirely decomposed,and the water turning quite green, it is allowed to run into another building called a beating vat. A dozen natives, with scarcely any covering upon their bodies, and with their skins dyed blue - deeply and darkly, if not beautifully, blue - may be seen here, striking the liquid with long sticks, and making a sound like the splashing of oars in a river. When at work they shout and scream, as indeed they always do when trying to exert their strength. After having been beaten for about three or four hours, and the green liquor having become blue, just as our black blood becomes red from contact with oxygen in the air, it is left alone, to allow the sediment to settle at the bottom. The water is then gradually drawn off by taps fixed at equal distances in the sides of the vat, leaving a beautiful, soft, blue, pulpy matter, like very thick cream, on the floor. This blue cream is next boiled, until no froth or scum rises to the surface, and the blue cream looks as smooth as liquid glass. It is then poured into huge sieves, made by streching coarse cloth over wooden frames, through which the water strains off gradually, leaving the indigo of the consistency of cream-cheese. It is still, however, unfit for travelling to Calcutta, and from thence to all parts of the world. It must, therefore, be put into boxes with perforated bottoms, where every drop of moisture is finally squeezed out by mechanical pressure. The pressed indigo is then cut into cakes about three inches square, and is put into a drying-house, where it remains for three months.

The indigo is now fit for packing and travelling. It is truly astonishing to see the quantities of this paste, which are annually sent from Bengal, for the use of the painters and dyers distributed all over the globe. Indigo, however, is not only employed in dyeing blue, but is necessary for the production of almost every other color. The indigo plant in itself is perfectly harmless, while the indigo paste prepared from it is a rank poison. When rubbed with the finger nail, the paste assumes a copper color.

The smell of an indigo factory is very disagreeable; and the Hindus who work in it, besides having their bodies dyed of a dreadful color, are very meagre; yet they are contented with the work, and do it well.

An European indigo planter in the interior of India leads an isolated life, which, however, is not without its enjoyments. His business though it has its anxieties, is now irksome. He is generally a farmer and a sportsman, and master and owner of a fine mansion, with plenty of elephants, Arabian horses, cows, sheep, goats, and dogs, and perhaps a few tame leopards and tigers. His elephants, besides being useful in enabling him to ride over his plantations, will carry him better than any other animal, when out in the jungles tiger-hunting. The planter often lives twenty or forty miles from any other European; but this does not prevent him from constantly making and receiving visits. Moreover, his time is well taken up with paying his people, superintending his vats, and settling disputes among the neighboring farmers. In his own district, the planter is perfectly independent, being looked up with awe and respect by all around him. In their hour of trouble, the poor, miserable, hard-worked, and ill-fed ryots or laborers always fly to the British planter for protection against the oppressions of their own masters and countrymen.

One of the annoyances of a planter's life is the plague of flies. All over India, they are a great nuisance during the rainy season, but nowhere to such a degree as in the vicinity of an indigo factory; were they are attracted by the smell. When the servants are preparing the table for a meal, they put a white muslin cloth over the plates, cups and saucers, and in an instant it is covered with black flies. Before taking off the muslin cloth, the bearer begins pulling the large geavy punkah or fan, which has generally a deep fringe at the edge of it; the waiters whisk about small fans in every direction to keep the flies from off the table; as soon as the tea is poured out, a silver cover is put over the cup.

In the cold season, from November to March, the planter generally spends a month in one of the towns, for the purpose of negotiating the sale of his indigo.

One of the first records to be found of the commerce in indigo occurs in a letter addressed by Lord Bacon to King James, supporting some complaints made by the East India company, in which he says that in return for English commodities, we received from India great quantities of indigo. And a work, entitled the Merchant's Map of Commerce, published in sixteen hundred and thirty-eight by Lewis Roberts, says, we then exported from England a considerable quantity of indigo to Turkey and Italy. Davenant, in his Discourses on the Public Revenues and Trade, mentions some exports of indigo from America in sixteen hundred and eighty-two. About the year seventeen hundred and thirty-two, the indigo plant was extensively grown, and its produce exported from Jamaica and the sugar islands; nevertheless England was obliged to pay more than two hundred thousand pounds annually to France for indigo. Some Carolina rice-planters found they were overstocking the European market with rice, and began to cultivate indigo; and, in seventeen hundred and forty-seven, they sent nearly two thousand pounds of indigo to England. Parliament having granted a bounty of sixpence per hundredweight on all indigo grown in any of our American colonies and imported into England, the cultivation of the blue-dye plant continued to be pursued in Carolina with such success that, in about ten years, the export of indigo amounted to four hundred thousand pounds a-year.

The cultivation of indigo plant is carried on at present in India, Egypt, and America; but the best indigo paste is manufactured in the Bengal Presidency. French, Germans, Italians, and the Arabs have all in turn tried to cultivate the indigo bearer in their own countries; and they have always failed, owing to the plant requiring a tropical climate for the production of the indigotine or blue coloring matter.

Respecting this precious chemical principle, the chemists tell us, that when a bit of indigo-paste is subjected to the influence of great heat, purplish vapors are seen rising from it, which, condensing upon cold bodies, form brilliant purple needles of indigotine.