The species generally cultivated is the I. tinctoria, which requires a rich moist soil and warm weather. The seed, which is at first sight not unlike coarse gunpowder, is sown three or four inches deep, in straight lines, twelve or fifteen inches apart. The shoots appear above ground in about a week; at the end of two months the plant flowers, when it is fit for cutting, which is done with a pruning knife. It must be mentioned that great care is requisite in weeding the indigo field when plants first shoot through the earth. In the State of St. Salvador, large vats made of mahogany, or other hard wood, are constructed for the reception of the plant, where it is allowed to undergo maceration and fermentation. In a short time the water becomes greenish, and emits a strong pungent smell, while carbonic acid gas is freely evolved. In about twenty-four hours it is run off into large flat vessels, and stirred about until a blue scum appears, when additional water is added, and the blue flakes sink to the bottom. The supernatant water has now acquired a yellowish tinge, when it is run off carefully, and the blue deposit or sediment put into bags to drain. It is subsequently dried in the shade, or sometimes in the sun, then placed in cotton bags and carried to the indigo fair, or forwarded to the city of Guatemala.
The East Indian mode of manufacturing the indigo differs materially, and many suppose it preferable to the Salvador. It consists in steaming the fermented mass in large pipes enclosed in huge boilers. I am inclined to believe this to be the most economical, if not the best way of manufacturing indigo. From Guatemala alone, it is computed that from 6,000 to 8,000 serons of indigo are exported annually; while San Miguel, Chalatenaugo, Tejulta, Secatecolnea, St. Vincent, Sensuntepepe, not only, it is said, produce a larger quantity, but the four last-mentioned places have the advantage as to quality. The Belize Advertiser stated, some time since, that the value of this dye from one State in 1830 produced 2,000,000 dollars, the minimum of an immense sum which has been most unjustly and unwisely wrested from the people of Jamaica, and the West India islands.
Bridges ("Annals of Jamaica," p. 584, Append.), speaking of the vast returns of an indigo plantation, says, "The labour of a single negro would often bring to his owner £30 sterling per annum clear profit,—a sum which was at the time the laborer's highest price. It continued the staple of Jamaica till an intolerable tax oppressed it, while its price was lowered by the competition of other colonies.
Its cultivation immediately declined throughout them all, but nowhere so rapidly as here. The financial error was quickly discovered,—a remedy was attempted by a bounty; but it came too late, the plantations were thrown up, and the planters, attracted by the temporary gain, abused the tardy boon, by introducing, as of their own growth, large quantities of foreign indigo." As Bridges may be said in this passage to be merely a commentator on Edwards, who has entered more largely upon the subject, I shall condense from the latter, statements connected with the manufacture and decay of this branch of industry, once the staple of Jamaica.
Edwards ("West Indies," vol. ii., p. 275, 2nd edition) reckons three kinds of indigo—the wild, Guatemala, and French. The first is the hardest, and the dye extracted from it of the best quality as regards color and grain; but one or other of the two species is commonly preferred by the planter, as yielding a greater return. Of these the French surpasses the Guatemala in quantity, but yields to it in fineness of grain and beauty of color. The indigo thrives almost on any land, though the richest soils produce the most luxuriant plants, and the longest dry weather will not kill it. The cultivation and manufacture our author thus describes:—"The land being prepared, trenches, two or three inches in depth, are made by the hoe. These are ten or twelve inches asunder. The seeds are then strewed in the trenches by the hand, and slightly covered with mould. When the plants shoot, they are carefully weeded, and kept constantly clean, until they rise high enough to cover the ground. A bushel of seed is sufficient for four or five acres. The best season for planting is March; but if the land be good, it may be sown at any time, and in three months the plants attain maturity. In seasonable situations, they have four cuttings in the year. The subsequent growths from the plants ripen in six or eight weeks; but the produce diminishes after the second cutting, so that the seeds should be sown every second year. A species of grub, or worm, which infests the plant on the second year is avoided by changing the soil; or, in other words, by a rotation of crops. The produce per acre of the first cutting is about 60 lbs. It is nearly as much in North America; but when the thermometer falls to sixty, the returns are very uncertain, that degree of heat being too low for the necessary vegetation, maceration, and fermentation. The yieldings for the subsequent cuttings somewhat diminish; but in Jamaica and St. Domingo, if the land is new, about 300 lbs. per acre of the second quality may be expected annually from all the cuttings together; and four negroes are sufficient to carry on the cultivation of five acres, besides doing other occasional work, sufficient to reimburse the expenses of their maintenance and clothing."
The process for obtaining the dye, according to the same author, was conducted through the means of two cisterns, the one elevated above the other, in the manner of steps. The higher, which was also the longer, was named the sleeper—its dimensions sixteen feet square and two and a half in depth. The second, into which the fluid was discharged, was called the battery; it was about twelve feet square, and four and a half in depth. These cisterns were of stone; but strong timber answered remarkably well. There was also a lime-vat, six feet square and four feet deep, the plug of which was at least eight inches from the bottom. This was for the purpose of permitting the lime to subside, before the lime-water was withdrawn. The plants then being ripe, or fit for cutting, were cut with reaping-hooks, or sickles, a few inches from the ground—six was the minimum—and placed by strata in the sleeper, until it was about three parts full. They were then pressed with boards, either loaded with weights or wedged down, so as to prevent the plants from floating loosely; and as much water was admitted as they would imbibe, until it covered the mass four or five inches deep. In this state it was allowed to ferment until the water had extracted the pulp. To know when this had been thoroughly effected, required extreme attention and great practical knowledge; for if the fluid were drawn off too soon, much of the pulp was left behind; and if the fermentation continued too long, the tender tops of the plants were decomposed, and the whole crop lost. When the tincture or extract was received in the battery, it was agitated or churned until the dye began to granulate, or float in little flakes upon the surface. This was accomplished at one period in Jamaica by paddles, worked by manual labor, and, in the French islands, by buckets or cylinders, worked by long poles; but subsequently—that is, at the time Edwards wrote—convenient apparatus was constructed, the levers of which were worked by a cog-wheel, kept in motion by a horse or mule. When the fluid had been churned for fifteen or twenty minutes, a small quantity was examined in a cup or plate, and if it appeared curdled or coagulated, strongly impregnated lime-water was gradually added, not only with a view to promote separation, but to prevent decomposition. Browne remarks ("Civil and Nat. Hist. of Jamaica," art. "Indigo"), the planters "must carefully distinguish the different stages of this part of the operation also, and attentively examine the appearance and color as the work advances,—for the grain passes gradually from a greenish to a fine purple, which is the proper color when the liquor is sufficiently worked,—too small a degree of agitation leaving the indigo green and coarse, while too vigorous an action brings it to be almost black." The liquor being then, as we shall suppose, properly worked, and granulation established, it was left undisturbed until the flakes settled at the bottom, when the liquor was drawn off, and the sediment (which is the indigo) placed in little bags to drain, after which it was carefully packed in small square boxes, and suffered to dry gradually in the shade.
Such is the account, nearly word for word, which Edwards gives of the mode of manufacturing indigo. I shall now quote his remarks upon the outlay and gain upon the article verbatim.—"To what has been said above of the nature of the plant suiting itself to every soil, and producing four cuttings in the year, if we add the cheapness of the buildings, apparatus, and labor, and the great value of the commodity, there will seem but little cause for wonder at the splendid accounts which are transmitted down to us concerning the great opulence of the first indigo-planters. Allowing the produce of an acre to be 300 lbs., and the produce no more than 4s. per pound, the gross profit of only twenty acres will be £1,200, produced by the labor of only sixteen negroes, and on capital in land and buildings scarce deserving consideration." Yet, notwithstanding this statement, the author informs us afterwards that he knew, in the course of eighteen years' residence in the West Indies, upwards of twenty persons who tried to re-establish indigo manufactories, but failed. This appears strange, since it is plain that what has once been done can be done again, but especially in the manufacture of an article requiring a capital so very small in proportion to the profits as almost to tempt the most cautious and the most timid man to embark in it.
I quote the following passage from the same author, for the purpose of showing the very loose manner in which statements are made on the authority of others, who are as incompetent to decide the merits of a question as the party himself chronicling their opinion. Speaking of the twenty unfortunate indigo-planters, our author thus writes:—"Many of them were men of foresight, knowledge, and property. That they failed is certain; but of the causes of their FAILURE I confess I can give no satisfactory account. I was told that disappointment trod close upon their heels at every stop. At one time the fermentation was too long continued, at another the liquor was drawn off too soon; now the pulp was not duly granulated, and now it was worked too much. To these inconveniences, for which practice would doubtless have found a remedy, were added others of a much greater magnitude—the mortality of the negroes, from the vapour of fermented liquor (an alarming circumstance, that, I am informed, both by the French and English planters, constantly attends the process), the failure of the seasons, and the ravages of the worm. These, or some of these evils, drove them at length to other pursuits, where industry might find a surer recompense."—(p. 283.)
The fallacy of much of this requires no comment, as it must strike even the most careless reader,—for if the so-called indigo-growers did not know the process of manufacturing the commodity, then it could not be surprising that they failed. Thus the cause of their failure required no comment, and no explanation. Were a ploughman taken from the field and placed at the helm of a ship, and the vessel in consequence wrecked, would any one be astonished but at the folly of those who placed him there? This was the case with the indigo-growers,—they attempted what they did not understand, and, consequently, lost their labor and their money. The mortality of the negroes employed, stated as another reason for abandoning the attempt, requires a somewhat more lengthy notice.
I can briefly say, that I have learned that in the Central States of America, deaths among indigo-laborers are not more frequent than in other branches of tropical industry; and I never heard or have read that the original growers complained of the mortality attending the progress. The truth is, that this statement is not founded on fact. There is nothing whatever in the manufacture of indigo, either in the cultivation or the granulation, or even the maceration and fermentation of the plant, which is directly or indirectly, per se, injurious to human life. I have certainly never seen the indigo plant macerated on a large scale; but I have myself steeped much of it in water, and allowed it even to rot, and found nothing in the mass differing in any marked degree from decomposed vegetable matter. It seems to me that this idea of the manufacture of indigo being especially inimical to human life, is as unfounded as the belief, even by Humboldt, up to a very recent period, that none of the Cerealia would grow in tropical climates. In conversing with an old gentleman in Jamaica, some twelve years since, who had tried the manufacture of indigo, and with every prospect of success, but abandoned it, as he confessed, for the cultivation of the sugar cane, since it was then more profitable, he suggested the solution, that as the manufacture was light work, probably aged and debilitated, in place of youthful and vigorous slaves, were too frequently employed in the process—hence the mortality. This may be correct to a certain extent; but I am also inclined to think that another cause of mortality might be found in the mode and manner in which the negro was fed and clothed, and not because aged persons were exclusively engaged in the manufacture. I believe I may state, without fear of contradiction, that the real cause of the decline and consequent abandonment of the indigo plant was the monstrous duty levied upon it by the English government. Indeed, this has been already stated in the extract from Bridges; while the cause of the failure of the attempt to renew it, over and above the reasons we have given, was the greater temptation to embark capital in sugar plantations,—the West Indies enjoying a monopoly in this article, while they had competitors in the Southern States of America in the other. I have, therefore, no hesitation in saying, that, with a trifling capital, under prudent management, indigo might be cultivated to a very great extent, and with considerable profit, even now, in Jamaica. But the adventurer is not to expect to count his gains, as the original growers did, by thousands; he must be content with hundreds, if not fifties; for at the present day every branch of industry is laden with difficulties, encumbered by taxation, and obstructed by competition. There are two objections, however, which I have not removed,—I allude to "the failure of the seasons and the ravages of the worm." Very little need be said to combat these. Seasons are mutable, and the same heaven that frowns this year on the labors of the husbandman, may smile the next; while a remedy for the "ravages of the worm" may be found in the mutation of the soil, the destruction of the grub, or the rotation of crops,—accessories to success which seem not to have entered into the vocabularies of the twenty pseudo indigo-growers, "many of them men of knowledge, foresight and property."