The Universal Herbal: Indigofera Tinctoria; Dyer's Indigo.

The Universal Herbal;
or botanical, medical and agricultural dictonary.
Containing an account of All the known Plants in the World, arranged according to the Linnean system. Specifying the uses to which they are or may be applied, whether as food, as medicine, or in the arts and manufactures.
With the best methods of propagation, and the most recent agricultural improvements.
collected from indisputable Authorities.
Adapted to the use of the farmer - the gardener - the husbandman - the botanist - the florist - and country housekeepers in general.
By Thomas Green.
Vol. I
Liverpool.
Printed at the Caxton Press by Henri Fisher.
Printer in Ordinary to His Majesty.
1824Leaves pinnate, obovate; racemes short; stems, suffruticose; branches, like the stem, alternate, upright; legumes drooping, subcolumnar, sharp, straight, very finely villose.

Linneus says that it is almost an exotic in Ceylon, but common in Paliacotta and Coromandel. According to Loureiro, it is spoutaneous all over China and Cochin-china. Dr. Patrick Browne, besides the Wild Indigo, mentions two other sorts which he calls the Indigo and the Guatimala Indigo: the first seldom above two feet and a half high, and seeming to divide rather than to branch in its growth, yielding more of the dye than any of the others, and generally preferred, though subject to many more mischances: the second commonly three or four feet high, throwing out many suberect branches as it rises; this is hardier than the former, and affords a finer pulp, but yields a less quantity, and is only cultivated where the seasons are certain, or in moist fields.

The ancients were acquainted with the dye which we call Indigo, and the name of Indicum. Pliny knew that it was a preparation of a vegetable substance, though he was ill informed both concerning the plant itself, and the process by which it was prepared for use.

From its colour, and the country from which it was imported, some authors call it Atramentum Indicum, and Indicum Nigrum. The American name is Nil or Anil, from which the Portuguese have adopted their Anil or Anileira; the other European nations generally call it Indigo. The Arabian name is Nile; and the Chinese, Tien Laam, or Sky Blue.

The works for steeping and fermenting this extremely valuable and useful plant, consist of three or five square cisterns or vats, well cemented, terrassed, and seasoned. They are made gradually smaller, and so situated as to have the top of the second and third on a line with the bottom of the first, or a little lower; and the top of the fourth and fifth on a line with or lower than the bottom of the second and third. The first is called the Steeper, and is generally made about eight or ten feet square by four deep, and opens into the second and third by round holes made close to the bottom, so as to discharge all the tincture readily; the second, or second and third vats, are called the Beaters. If there be only one, and the liquor is to be worked up with hand-buckets, it should be eight or ten feet square, and six deep; but if there be two, and the tincture is to be beaten with an engine, they should be so deep as to hold all the liquor a good way below the main or horizontal axis into which the buckets are fixed; and the walls should be nearly as high over the rollers as the cistern is deep below them, to prevent the wasting of the tincture. After the liquor is well beaten, it is left to settle; and when the pulp is deposited, the clear fluid is drawn off by a vent placed some inches above the bottom of each cistern: and the remainder is discharged into the fourth and fifth cisterns, by convenient outlets placed close to the bottom. These last cisterns are small, and are generally made square, and proportioned to the quantity of pulp such works commonly produce at a time. When the works are in good order, and the plants cut and carried to them, they are laid in the steeper; and when that is pretty full, boards are laid over them supported by props, from the beams that overlay the cistern: when these are well settled, they pour in as much water as will cover the weed, and leave it to digest and ferment until the greatest part of the pulp is extracted, without letting the tender tops run to putrefaction; and in the management of this point, the judgment of the planter chiefly consists; for, if he draws off the water but two hours too soon, he loses the greatest part of the pulp; and if the fermentation runs but two hours too long, the whole is spoiled: they frequently, therefore, draw out a handful of the weed, and when they find the tops grow very tender and pale, and observe the stronger leaves change their colour to a less lively pale, they draw the liquor off without delay. They soon learn to know this critical point by the height of the fermentation, and grain of the tincture; of which they frequently beat a little in a silver cup kept for that purpose: the pulp being thus extracted, the tincture is discharged into the beaters, and there worked up by two or three n***s, each with a bucket, or by an engine; they agitate it until the dye begins to granulate, or float in little flosculae in the water, which separation is greatly forwarded by a gradual addition of clear lime-water: the different stages of this operation are distinguished by examining a small quantity of the liquor in the silver cup, from time to time; and a little experience soon teaches them when to stop, by a single drop upon the nail, at any degree of height, as they would have their indigo of a deep copperish blue, or of a paler colour: the liquor is now left undisturbed, until the flosculae settle, then the water is discharged, and the magma or mud let out by a lower vent into its proper receptacles; this is again by some put into a cauldron, and heated over a gentle fire, but not so as to boil, and then emptied into little bags to drain; by others, it is not heated, but immediately put into the bags; it is afterwards put into square boxes, with sides not above four inches deep, that it may dry the sooner, without crumbling.


Propagation and Culture.

In the West Indies, Indigo seems to thrive best in a free rich soil, and a warm situation, but, to answer the planter's ends, it should be cultivated where it may be frequently refreshed with moisture: having chosen a proper piece of ground, and cleared it, hoe it into little trenches, not above two inches or two inches and a half in depth, nor more than fourteen or fifteen inches asunder; in the bottom of these, at any season of the year, strew the seeds pretty thickly, and immediately cover them: as the plants are short, they should be frequently weeded, and kept constantly clean, until they spread sufficiently to cover the ground. Those who cultivate great quantities only strew the seeds pretty thickly, in little shallow pits, hoed up irregularly, but generally within four, five, or six inches of one another, and covered as before: plants raised in this manner are observed to answer as well, or rather better, than the others, but require more care in the weeding. They grow to perfection in two or three months, and are observed to answer best when cut in full blossom; this is done, with rape-hooks, a few inches above the roots: they are then tied in loads, carried to the works, and laid by strata in the steeper. Seventeen negroes are sufficient to manage twenty acres of indigo; and one acre of rich land will, with good seasons and proper management, yield five hundred pounds of indigo in twelve months, for the plant [], and gives four or five crops a year, but must be afterwards replanted. Mr. Miller thought the planters of indigo sowed their seeds too thick, which drew up the plants with slender stems, not sufficiently furnished with leaves, and those leaves not so large and succulent as if the plants were allowed a greater share of room.

It is a common observation among the cultivators of woad, that juice, when the plants spire, and have narrow thin leaves, they produce little dye; they not only therefore make choice of rich strong land, but carefully thin the plants, to allow them room to spread, and produce large succulent leaves. If the planters of indigo in America would imitate the cultivators of woad in this practice, they would certainly find it highly advantageous. Another error is, suffering the plants to stand too long before they cut it; for the older it is, the drier and firmer are the stalks, and the less will be dissolved by fermentation; nor will the faeces of old plants be half so beautiful: it is therefore highly desirable, that the planters should try the effects of sowing thin, keeping the plants perfectly clean, and cutting them while young and full of juice. The dearness of labour in the West Indies may be the principal objection to this method of cultivation, but the seeds might be sown with a drill plough; and, by the use of the hoe-plough, ten acres may be kept free from weeds, at as little expense as one with the hand-hoe; and by stirring the ground often, and earthing up the plants, they would grow much stronger, be less liable to be destroyed by insects, and produce larger and more succulent stalks and leaves. Though all seasons will admit of sowing indigo, care must be taken to avoid a drought, because the seeds may by eaten by vermin, carried away by the wind, or choked by the weeds: the planters usually choose a season that promises rain, and then they are sure of seeing the plant spring up in three or four days. It has been introduced into Jamaica only of late years.