by Abraham Rees, D.D. F.R.S. F.I.S. S.Amer.Soc.
with the assistance of Eminent Professional Gentlemen.
London, Printed for Longman, Hurst, Rees, Orme, & Brown, 1819
Woad, in Agriculture, a plant cultivated in the field for the use of the dyers. It is a plant which has a strong thickish fibrous root, which penetrates deep into the soil, and which is principally raised for the use of the leaves, which, after being properly manufactured, are made use of in the art of dyeing to produce a blue colour, as well as the bafis of black, and some others.
Soil.
It is evident from the nature of its root that it requires a soil which has much depth or staple, and which is perfectly fresh, such as those of the rich, mellow, loamy, and deep vegetable kind. Where this sort of culture is carried to a considerable degree of perfection, as in Lincolnshire, the deep, rich, putrid, alluvial soils on the flat tracts extending upon the borders of the different large rivers are chiefly employed for the growth of this sort of crop; and it has been shewn by repeated trials that it answers most perfectly when they are broken up from a state of sward immediately for it. In some places, it is the practice to take lands of this description at high prices, for the purpose of breaking them up and growing it upon them for two or three years; on the more low rich soils, for four years, but on those of less fertility only for three; and in some, which are more elevated and exposed, two are considered sufficient. For this sort of culture, people are employed, who move from place to place, and form a sort of colony. Mr. Cartwright, in the above county, has however found, that it is capable of being confined to one spot with equal or greater success, by having a sufficient extent of ground for changing the place of its growth as may be necessary, and for appropriating an adequate proportion annually to the raising of the plant, by which the houses and expensive machinery that are necessary for its preparation may be kept constantly and regularly employed in the business.
Preparation.
In order to prepare the land for this crop, it is advised by some to plough it up with a good deep furrow, immediately before the winter commences, laying it in high narrow ridges, to have the full effect of the frosts; and early in the spring to give another ploughing in the contrary leaving the ground in the same kind of ridge as before. When it has remained in this state some length of time, and weeds appear, it should be well harrowed down with a heavy harrow, repeating the operation so as to render it perfectly fine and clean. About the beginning of June a third ploughing should be given to the full depth with a narrow furrow, and the land be afterwards well harrowed down as before; the fourth or final ploughing being given towards the beginning of July, in a light manner, leaving the surface as even as possible for the seed. But some take much less trouble in the business of preparation. In cases where the soils are sufficiently dry, only breaking them up early in the month of February; and where the contrary is the case, deferring it to a later period, taking care to plough the land in a perfect manner to the depth of five inches, or more: and that the furrow-slices a may be well turned, laid flat, and nicely jointed, a person is employed with a spade for the purpose of adjusting them. This prevents the grassy matters from rising in the seams. When this has been done, the surface is repeatedly harrowed over, to raise a sufficient depth of good mould for the drill to work in; and before the seed is put in a roller is passed over the land.
It is probable, however, that this method is inferior to the former, as the land is not brought nearly to so fine a state of mould, or the grassy material to effectually covered and destroyed, from which injury may be done to the woad plants in their early growth.
But a method which is equally effectual with the first, more expeditious, and which has a superiority over it, in more completely destroying grubs, insects, and other vermin, which are apt to feed on the plants in their early growth, is that of paring and burning. This is, however, chiefly practised where the sward is rough, and abounds with rushes, sedge, and other plants of the coarse kind, but might be had recourse to on others, with vast benefit.
Where the latter modes are made use of as soon as the seed has been put in, the land should be carefully drained by forming grips in suitable directions, as wherever water stagnates, the woad plants are liable to be injured or destroyed.
Seed.
In respect to the seed, it should be collected from ground that has been left covered with the best plants from the preceding season, as they only run up to stem and form seeds in the second year; and in order to have good seed, the leaves should not be cropped at all or but once, the stems being suffered to remain till the seeds in the hulks become perfectly ripened; which is shewn by their attaining a brownish-yellow colour, and the pods having a dark blackish appearance. It should then be gathered as soon as possible, by reaping the stems in the manner of grain, and then spreading them in rows thinly upon the ground if the weather be fine, when in the course of a few days they will be in a state to be threshed out from the hulks or pods. When they are suffered to remain too long, the pods are liable to open, and shed the seed. Although the pod in which the seeds are contained is of a large fine, the seeds are less than those of the turnip. New seed, where it can be procured, should always be sown in preference to such as has been kept for same time; but when of the latter kind, it should be steeped for same time before it is put into the ground.
In regard to the quantity of seed which is necessary, it must be regulated by the soil, and the manner in which it is sown. Where the drill is employed, less will be required than in the broadcast method. It has been found that a rood of land, where the crop is good, will in general afford seed sufficient for eight or ten acres; and in same cases, in the broad-cast method, five or six bushels are made use of to the acre. In Kent they use ten or twelve pounds to the acre.
Sowing.
The time of fawing crops of this nature must be regulated, in same degree, by the mode of preparation that leas been employed. Where the first of the above methods has been followed, it will be much later than in the other cases. But early lowing is in general to be preferred, as there will be less danger of the plants being injured by the attacks of the fly or grub. Where the weather is suitable, and the land in a proper slate of preparation, the seed may be sawn in the latter end of February or March, continuing the sowings, in different portions of land, till about the middle of May, at suitable intervals of time to vary the times of cropping the leaves of the plants. The late sowings are commonly executed about the latter end of July, or early in the following month at the farthest.
With respect to the manner in which the seed is sawn, it differs according to the nature and state of preparation of the land. Where it is in a fine state of mould, the drill or row method is the method mostly practised, which is by much the best, as by it the plants may be kept more easily clean and free from weeds, becoming more strong and vigorous, from the earth being more stirred about the plants: but where the contrary is the case, the broad-cast mode is generally followed; but which does not by any means admit of the plants being kept so free from weeds, or the mould so well stirred about the roots of them.
Where the first method is had recourse to, the seed is sown by a drilling-machine, such as is used for turnips, in equidistant rows, eight or nine inches apart, covering it in, either by means of a harrow attached to the implement, or by passing a light common harrow over the ground afterwards, once in a place, raking off any clods that may be present to the sides, or into the furrows: but in the latter mode, it must be dispersed by the hand in as equal a manner as possible, over the whole of the land, being than harrowed in by a light harrow, so as to leave the land in as even and level a state as possible. The ground is frequently rolled afterwards, that the surface may be left as even as possible.
In favourable seasons with good seed, the plants mostly appear in the course of a fortnight, when much attention should be paid to fee that they are not destroyed by the turnip-fly, or the frosts in those of the more early sowings; as, where that is the case, the land should be immediately refown as in same cases it is not uncommon to sow the greatest part of the crop two or three times over. In the very late sowings, where the crops rise thin on the ground, it is sometimes a practice to give a better plant by forming holes with a hoe in the vacant spots, and directing seeds to be dropped into them by the hand by women or children. This is the case with the late spring-sowings till the beginning of June, or a later period.
Culture while growing.
From much of the goodness of the woad plants depending on the luxuriance of their growth, and the thickness of their leaves, it is necessary to bestow great attention in the culture of the crop while growing. It is advised that the spring-sown crops, as well as those that are sown in the latter part of the summer, should have the first hoeings given them as soon as the plants are fully distinguishable above the ground, as by this means the weeds will not only be prevented from retarding the vegetation of the plants, but these by being thinned out to greater distances be more at liberty to advance and become vigorous in their first or early growth, which is a matter of much consequence to the success of the crop; and second hoeings should be given in the course of four or five weeks afterwards, when the plants should be thinned out to the full distances at which they are to stand, which may be six or seven niches, or more, according to the goodness of the soil, constantly leaving sufficient room to prevent the plants from being in any way crowded. The work is sometimes executed in much the same manner as for turnips, by hand-hoes; but in others by small short spuds, used with one hand, while the other is employed in clearing away the weeds: the labourers, mostly women and children, kneeling while they perform the work. When this work has been done, nothing further is necessary till the first cropping of the leaves has been performed, when the plants should be again immediately well weeded; and after each cropping the same operation be had recourse to; the extent of crop cleared in the day being, in most cases, weeded before night.
With the late-sown crops, after the second weeding in October, nothing further will be requisite till the spring, about the middle of April, when the work should be again well executed, the mould being completely stirred about the roots of the plants, that they may derive the fullest benefit from the operation. This will be sufficient to keep them clean till the taking of the first crop; after which they must be again weeded, and the same operation be had recourse to after each cropping of the leaves, as in the above case.
In respeet to the business of gathering the crops with the spring-sown ones, the leaves will generally be ready to be gathered towards the latter end of June, or beginning of July, according to the nature of the soil, season, and climate; but for those put in at a later period in the summer, they are often fit to be gathered earlier. This business should, however, constantly be executed as soon as the leaves are fully grown, while they retain their perfect green colour, and are highly succulent; as when they are let remain till they begin to turn pale, much of their goodness is said to be expended, and they become less in quantity, and of an inferior quality for the purposes of the dyer. In favourable seasons, where the soils are rich, the plants will often rise to the height of eight or ten inches; but in other circumstances they seldom attain more than four or five: and where the lands are well managed in the culture of plants, they will often afford two or three gatherings, but the best cultivators seldom take more than two, which are sometimes mixed together in the manufaauring of them. It is necessary that the after-croppings, when they are taken, are constantly kept separate from the others, as they would injure the whole if blended together, and considerably diminish the value of the produce. It is said that the best method, where a third cropping is either wholly or partially made, is to keep it separate, forming it into an inferior kind of woad.
Upon an acre of land, when well managed, in favourable seasons, the produce is mostly from about a ton to a ton and a half. The price varies considerably; but for woad of the prime quality, it is often from twenty-five to thirty pounds the ton, and for that of art inferior quality six or seven, and sometimes much more.
Seeding-Crops.
With such parts of the crops as are reserved for seed, it is a practice with force to crop the leaves two or three times the first year, and then leave the plants to run up to seed in the following one; but it is a better ractice to only remove the side-leaves, as in this way the plants are less weakened, and the produce of the seed much increased. The plants are likewise sometimes sed down by sheep during the winter season; but this, from its tendency to weaken them, is equally improper and prejudicial.
Preparation of for the Dyer.
The woad, after it has been gathered, undergoes several processes to prepare it for the dyer; but in the improved method it is conveyed in one horse carts, so contrived as to be lifted from the axis, and, by folding doors in the bottoms, to discharge their contents upon the floor above the mill, on being hoisted up to their proper situation: round this floor holes are formed for putting the plants down through, in order that they may drop under the grinding-wheels. The mills for this purpose have several wheels for grinding the plants, which have less diameters on one side than the other, and are about three feet in width, being construaed with iron bars for crushing the woad. They are wrought by horses, or any other power, as may be the most convenient. The materials are preserved under the grinding-wheels by proper contrivances, which, as soon as they are sufficiently reduced, force it out of the tracks upon the stone floors on the sides; thus making way for new parcels without the mill being slopped. The bruised woad is then thrown into rooms on the sides of the mill, destined for its reception, by means of shovels. In these it remains till the juicers so much drained off as to leave it in a proper condition for being formed into balls; which is done by labourers, with apparatus for the purpose, and then laid upon trays to be conveyed to the drying ranges, in which they are placed upon grating-shelves that slide on fledges in the drying-houses. There are placed on the sides of galleries, for the convenience of being easily deposited upon them and removed again. It is kept in these till it is sufficiently dried to be laid up in other rooms, until the whole of the crop has undergone the same operations, and the workmen are ready to manufacture it.
It is stated in the Corrected Lincolnshire Report on Agriculture, that to prepare it for use in the art of dyeing, it is necessary for it to take on a proper state of fermentation, which is accomplished in the course of seven or eight weeks, and, in the technical language of the art, is termed couching. It is effected by regrinding the balls, in the same mill as before, to a fine powder and then spreading it upon the floors of the rooms in which the balls were formed, to the thickness of about three feet; where it is then moistened with water, so as to keep it in a proper flow state of the fermentation; and so managed by turning that it may pervade the whole in an equal manner. In this business, the direetion of an experienced workman is necessary. In the turning, it is of much importance that the parts of the materials be perfectly divided, which can only be effected by a nice management of the shovel: and it is added that much advantage has been found in the goodness of the woad, from the drying and storing of it being performed in a careful manner. When this attention is neglected, the woad will not, on being broken between the finger and thumb, draw out into fine hair-like filaments, or, in the technical language of the manufacturer, beaver well; as the use of this substance in the blue vat of the dyer, is not merely to afford the colour of the plant, but, by bringing on a very gentle fermentation, excite the indigo in the same vat to yield its colouring principle more perfectly. This is eves necessary for its own colouring-matter being fully imparted. The substance should, therefore, be so prepared in the different operations as to produce this effect in the most certain and perfect manner. When the heat in the process of couching has gone too far, the substance will be what is termed foxy; and when it has not proceeded to a sufficient degree, it will be what is called heavy. If the material be good, it does not soil the fingers on being rubbed between them; but such as is heavy does. In the conclusion of the process, the cooling is effected in so gradual a manner, as to render it not fit for taking on the same process; and of course proper for being preferred in casks, or in any other way. It is then ready for use.
The preparation of woad for dyeing, as practised in France, is minutely described by Astruc, in his Memoirs for a Natural History of Languedoc. The plant puts forth at first five or six upright leaves, about a foot long, and six inches broad: when these hang downwards, and turn yellow, they are fit for gathering: five crops are gathered in one year. The leaves are carried directly to a mill, much resembling the oil or tan-mills, and ground into a smooth paste. If this process was deferred for some time, they would putrefy, and send forth an insupportable stench. The paste is laid in heaps, pressed close and smooth, and the blackish craft, which forms on the outside, reunited if it happens to crack: if this was neglected, little worms would be produced in the cracks, and the woad would lose a part of its strength. After lying for fifteen days, the heaps are opened, the crust rubbed and mixed with the inside, and the matter formed into oval balls, which are pressed close and solid in wooden moulds. There are dried upon hurdles: in the sun, they turn black on the outside; in a close place, yellowish, especially if the weather be rainy: the dealers in this commodity prefer the first, though it is raid the workmen find no inconsiderable difference betwixt the two. The good balls are distinguished by their being weighty, of an agreeable smell, and when rubbed of a violet colour within. For the use of the dyer, there balls require a farther preparation: they are beat with wooden mallets, on a brick or stone floor, into a gross powder; which is heaped up in the middle of the room to the height of four feet, a space being left for palling round the sides. The powder, moistened with water, ferments, grows hot, and throws out a thick fetid fume. It is shovelled backwards and forwards, and moistened every day for twelve days; after which it is stirred less frequently, without watering, and at length made into a heap for the dyer.
The powder thus prepared gives only brownish tinctures, of different shades, to water, to rectified spirit of wine, to volatile alkaline spirits, and to fixed alkaline lixivia rubbed on paper, it communicates a green stain. On diluting the powder with boiling water, and after standing same hours in a close vessel, adding about one-twentieth part of its weight of lime newly slacked, digesting in a gentle warmth, and stirring the whole together every, three or four hours, a new fermentation begins, a blue froth arises to the surface, and the liquor, though it appears itself of a reddish colour, dyes woollen of a green, which, like the green from indigo, changes in the air to a blue. This is one of the nicest processes in the art of dyeing, and does not well succeed in the way of a small experiment.
Astruc proposes the manufacturing of fresh woad leaves in Europe, after the same manner as the indigo plant is manufactured in America; and thus preparing from it a blue fecula fimilar to indigo, which from his own experiments he has found to be practicable. Such a management would doubtless be accompanied with same advantages, though possibly woad so prepared might lose those qualities which now render it, in a large business, preferable on same accounts to indigo, as occasioning greater dispatch when once the vat is ready, and giving out its colour less hastily, so as to be better fitted for dyeing very light shades. Neumann's Chem. by Lewis, p. 437, &c.
The ancient Gauls and Britons used to dye or stain their bodies with this plant, and were probably led from this application of it to use it for dyeing cloth.
Some hold that it was from this plant glass took its denomination; though others derive both glass and glastum from the British glass, which to this day denotes a blue colour. See GLASS.
A woad blue is a very deep blue, almost black; and is the base of so many sorts of colours, that the dyers have a scale, by which they compere the divers calls or degrees of woad, from the brightest to the deepest.
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