Kiln-drying,—The size and mode of constructing the kiln may be varied to suit circumstances. The following is a very cheap plan, and sufficient to dry one ton of roots at a time. Place four strong posts in the ground, twelve feet apart one way, and eighteen the other; the front two fourteen feet high, and the other eighteen; put girts across the bottom, middle, and top, and nail boards perpendicularly on the outside as for a common barn. The boards must be well seasoned, and all cracks or holes should be plastered or otherwise stopped up. Make a shed-roof of common boards. In the inside put upright standards about five feet apart, with cross-pieces to support the scaffolding. The first cross-pieces to be four feet from the floor; the next two feet higher, and so on to the top. On these cross-pieces lay small poles, about six feet long and two inches thick, four or fire inches apart. On these scaffolds the madder is to be spread nine inches thick. A floor is laid at the bottom to keep all dry and clean. When the kiln is filled, take six or eight small kettles or hand-furnaces, and place them four or five feet apart on the floor (first securing it from fire with bricks or stones), and make fires in them with charcoal, being careful not to make any of the fires so large as to scorch the madder over them. A person must be in constant attendance to watch and replenish the fires. The heat will ascend through the whole, and in ten or twelve hours it will all be sufficiently dried, which is known by its becoming brittle like pipe stems.
Breaking and grinding.—Immediately after being dried, the madder must be taken to the barn and threshed with flails, or broken by machinery (a mill might easily be constructed for this purpose), so that it will feed in a common grist-mill. If it is not broken and ground immediately, it will gather dampness so as to prevent its grinding freely. Any common grist-mill can grind madder properly. When ground finely it is fit for use, and may be packed in barrels like flour for market.
Amount and value of product, &c.—Mr. Swift measured off a part of his ground, and carefully weighed the product when dried, which he found to be over two thousand pounds per acre, notwithstanding the seasons were mostly dry and unfavorable. With his present knowledge of the business, he is confident that he can obtain at least three thousand pounds per acre, which is said to be more than is often obtained in Germany. The whole amount of labor he estimates at from eighty to one hundred days' work per acre. The value of the crop, at the usual wholesale price (about fifteen cents per pound), from three to four hundred dollars. In foreign countries it is customary to make several qualities of the madder, which is done by sorting the roots; but as only one quality is required for the western market, Mr. Swift makes but one, and that is found superior to most of the imported, and finds a ready sale.
Madder is produced in Middle Egypt to some extent, for the consumption of the country, principally for dyeing the tarbouche or skull caps which are universally worn. Its culture was introduced in 1825. In 1833, 300 acres in Upper Egypt, and 500 in the Delta and the Kelyout, were devoted to madder roots.
New South Wales is eminently suited to the culture of this valuable root, and as the profits upon its cultivation are very large, I would strongly recommend it to the attention of agriculturists there. The article produces to France an annual sum of one million sterling; the price of the finest quality in the English market being £60 per ton. Its yield varies from £40 to £50 per acre, and the expenses upon its proper culture should not exceed one-half that amount. The colonists would find it to their interest to turn their attention to such articles as this, for which there is an extensive demand at home, instead of confining themselves exclusively to the commoner and bulkier products, which they export at a much less profit, and which when once the market is fully supplied, may fall to a price at which they cannot afford to sell.
The following is a calculation of the expenses generally supposed to attend a crop according to the mode of cultivation practised in Vaucluse:—
| £ s. | d. | |||||
| Rent per hectare (2½ English acres), 3 years, at 165 francs | 19 | 17 | 6 | |||
| Manure, 440 francs | £17 | 12 | 6 | |||
| Carriage of ditto, 132 francs | 3 | 5 | 10 | |||
| 22 | 18 | 4 | ||||
| £42 | 15 | 10 | ||||
| These expenses may almost be dispensed with in our colonies, as the soil at Vaucluse has long been exhausted. | ||||||
| Two and a-half acres require 170 lbs. seed, at 2½d. per pound, which, with the labor afterwards bestowed, including the cost of spade trenching, will be | 30 | 0 | 0 | |||
| £72 | 15 | 10 |
The average produce per hectare is 77 cwt., which, at £1 4s. 2d. per cwt. (the price on the spot), is £93. The price is now much lower, but still it is clear a most profitable return would be derived from the first crop, and a proportionably larger one afterwards.
A considerable portion of the madder roots, instead of being ground and exported in that form, as heretofore, is now exposed, after being invested with dilute sulphuric acid, to a boiling heat by means of steam, by which the coloring matter is considerably altered and improved in quality for some dyeing processes, while the quantity rendered soluble in water is greatly increased. The madder so prepared is known as "garancine," and forms an important branch of manufacture in the south of France, which was well illustrated at the Great Exhibition in 1851, by a collection of specimens supplied by the Chamber of Commerce of Avignon. The spent madder, after being used in dyeing, is now also converted by Mr. H. Steiner, of Accrington, into a garancine (termed garanceuse by the French) by steaming it with sulphuric acid in the same manner as the fresh madder, and thus a considerable quantity of coloring matter is recovered and made available which was formerly thrown away in the spent madder. Both varieties of garancine give a more scarlety red than the unprepared madder, and also good chocolate and black, without soiling the white ground, but are not so well fitted, particularly the garancine of spent madder, for dyeing purples, lilacs, and pinks. The value of the garancine imported from France in 1848 was £59,554, and of that imported in 1851 £93,818. This preparation of ground madder is imported into Liverpool to the extent of from 500 to 600 tons annually from Marseilles, for the use of calico printers in the manufacturing districts. The price is £7 to £8 the ton.