A preparation of the colouring matter of madder, known as Fleurs de Garance, is made in the follow ing way :—The madder is mixed with 8-10 parts of water, and left for 3-4 days, at a temperature of 24°-27° F.), when fermentation ensues, transforming the sugar of the root into alcohol. The latter may be collected, and used for technical purposes, the yield being about 15 gal. from a ton of madder. The purified colouring matter amounts to about 55-60 per cent. of the madder. A more concentrated preparation is " garancine," prepared by treatment with sulphuric acid, which destroys much of the woody fibre, and affords about 25 per cent. of a fine light-brown colour. The pure colouring principles, alizarin° and purpurine, are separated by the following method :—Madder, GOO lb., is macerated for 12-15 hours with 800 gal. of a weak solution of sulphurous acid, com bined with 0.001 part of hydrochloric acid, to neutralize earthy carbonates present in the root. The operation is repeated three times ; to the liquors, is added 3 per cent. sulphuric acid, and the whole is heated up to 60° (140° F.); red flakes are deposited ; these, washed and dried, are commercial purpurine. The liquor is then boiled for 2 hours, and left to cool ; a dark-green powder is preci pitated ; washed and dried, it forms alizarine verte. The product of purpurine is i-1 per cent. ; and of alizarin°, 3-4 per cent. Extracts of madder are produced by treating the roots with boiling water, collecting the precipitates separated on cooling, mixing them with gum or starch, and adding acetate alumina or iron. This forms a ready merdanted dye, which may be directly used in calico printing.
The consumption of this once all-important red dye is now on the wane in England. Our im ports, in 1878, were as follows :—Madder : from Holland, 16,750 cwt.; France, 4508; other countries, 601 ; Madder root : Turkey, 4224 cwt.; Holland, 3354; other countries, 3339 ; Garancine : France, 1762 cwt.; other countries, 820. In 1879, they were respectively :-10,822, 2862, 28, 0, 5819, 1932, 1071, and 418 cwt. Turkey madder root, which is considered the best, is now worth about 13-14s. a cwt. ; in 1868, the prices were :—French madder, 45s. ; Turkey roots, 50s.; garan cine, 150s. The cultivation of madder in England has never been attended with success, from climatic causes ; moreover, it could not be made remunerative except where land is very cheap, and where eoal-tar are not produced. These conditions are fulfilled in many of our Colonies ; several of the Australian Droserm yield an identical (or nearly so) colouring matter, and may repay cultivation. The production in France, where formerly the plant was very extensively grown, espe cially in the department of Vaucluse, whose principal town, Avignon, was renowned for this article, fell, in 1878, to about 14,000 cwt., the yield of about 1000 acres. In 1871, nearly 30,000 acres gave over 263,000 cwt. Here the plant is generally raised from seed, sown in the spring. Holland was estimated to produce annually about 14. million lb. of madder roots a few years since. The beet were grown in the islands of Sohowen and Duiveland, and in the district comprised between the mouths of the West Escourt and the Belgian border. The cultivation in Italy has been entirely abandoned, yet, in 1878, some 24,000 cwt. of roots were still on hand in Naples.
The plant grows wild throughout a large portion of Central Asia and S. Russia. It is also culti vated more or less in many districts, notably about Kouban in Baku, and around Derbend. The best is said to be produced in Astrakhan, Derbend, and Trans-Caucasia, the last being known as " Persian " ; the qualities of the growths of Kokhand, Bokhara, and Khiva, are in the order given. The best Persian madder comes from Yezd.
Successful attempts have been made to cultivate madder in some of the United States, as at Columbus and Birmingham, in Ohio; at Montague, Franklin Co., Massachusetts ; and on the Con necticut River.
Mexican Blue.—The colouring matter of Sericographis Mohiti, a native of Mexico, serves the indigenous inhabitants as a blue dye for textiles, which are simply plunged into a hot decoction of the plant itself. The colouring principle bears much resemblance to litmus, being reddened by acids, and then rendered violet by alkalies.
Munjeet (Fa., Garance des _fades ; tIER., Munjeet).—A product much resembling madder, and very generally replacing it in Eastern industry, is afforded by the plant known as munjeet, an Indian name, applied not only to .Rubia Munjista (cordifolia), but also, it would seem, to R. tinctoria, or true madder. The plant is cultivated in many parts of India, as Assam, Nepal, and Bombay. The dried root has occasionally reached this country, but was unable to compete with European madder, as its colours were neither so bright nor so fast. It is, however, a very important article of export over the Himalayas to Thibet, where great quantities are consumed in dyeing the garments of the Lhamas. Our imports, in 1878, were 285 cwt. The London market value is about 20s.-25s. a cwt.
Nag-kassar.—The flower-buds of Mcsua ferrea (see Perfumes) are used in India for dyeing silk ; they have once been introduced into the London market, under the name " Nag-kassar," a corruption of the Bengalee Nag-hushur.
Orchella (FR., Orseille, Tournesol ; GER., Orsedle).—Three colouring matters, known respec tively as Orchil, Cudbear, and Litmus, are obtained from two species of lichen, .Rocella tinctoria, and B. fuciformis, found growing in the Canary Isles, the Cape Verde, Sardinia, Madagascar, Zanzibar, and Angola, but commercially obtained chiefly from Central America. From recent studies of R. fuciformis, it is concluded that the lichen contains two colouring matters already formed, while a third (red) is developed by The lichen is treated with hot water, to extract the greeu principle; then with alkaline carbonate (preferably soda), to remove the red element ; and finally with alcohol, to obtain a solution of the yellow colouring matter. The consumption of orchil in this country is now almost entirely superseded by the aniline dyes, though it is occasionally employed for " topping " cheap indigo blues on cotton goods. The exports of this article iu 1878 were, from Mogador, 60 cwt., value 90l.; from Guayaquil, 738 quintals (of nearly 2 cwt.), value 1107/. ; all to Great Britain. The London market values are approximately as follow :—Ceylon and other E.Indian, 20-45s. a cwt. ; Zanzibar and Mozambique, 28-40s. ; Guayaquil, 30-35s. ; Californian, 24-25s.