MADDER.

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cl the Levant are in full perfection before the end of a twelvemonth.Alsace, Baden, and Wurtemburg madders are perfect in about sixteen tonineteen months. Zealand madder, reaches its climax, for all shades, atfrom twenty to twenty-six months. This is the unanimous testimony ofMulhouse, Rouen, Elberfeld, and other places where this material is con-sumed, and is supported by Gasparin, Girardin, Previnaire, and otherscientific men, that no known kind of madder produces then such fast, suchbrilliant, and such intense colours as that of Zealand. There is the drawbackof clearings, and, as regards the white portions of tissues, almost an impos-sibility of brightening them without grass-bleaching. The other kinds ofmadder are entirely spoiled, even within a few weeks after having reachedmaturity. Zealand madder, if properly kept, is—even at thirty-six months ofage—quite fit to dye excellent deep browns and exceedingly beautiful blacks.Gasparin accounts for this by the mode of cultivation to a great extent, andby the peculiarities of the soil. The proper packing of the material and thecare of warehousing it in suitably constructed and ventilated—yet dark *—buildings have been proved to have much to do with the good qualities ofZealand madder, by the experience of the brokers and warehousemen whohave charge of this article at Rotterdam. There higher rents are readily paidfor warehouses suitably constructed to keep madder. An equable temperatureis also a great point.

We now return to fleur de garancc, from its mode of preparation we mayalready infer that, as is the case with madder, the colouring matter intimatelycombined with and pre-existing in the woody fibre is lost. According to M.

H. Schlumberger, 100 parts of flours de garance are equal to 200 of madder,but the loss of colouring matter just alluded to is the same for both, andamounts to about 45 per cent. Hence for bloom of madder, as well as for rawmadder, there exists the necessity of treating the residues for garanceux,about which we shall treat presently.

We have now to treat of Garancin (once known as Lagier’s bloom ofmadder). The principle of the manufacture of garancin is based upon theaction which sulphuric acid, in a more or less concentrated state, has uponmadder, whether previously washed or unwashed with water. The aCtion ofthe acid destroys a portion of the woody fibre, and while it does not affeCt the *genuine colouring principles it removes the useless vegetable matter, dissolvesthe calcareous and other combinations of the colouring substances, and setsso much of the latter entirely free that a real gain is obtained, so great as to,cover far more than the expense of the acid and the manipulations required.

As far back as the year 1828 Robiquet and Colin wrote a paper, presented tothe Societe Industrielle de Mulhouse, “On the Concentration of Madder byMeans of Sulphuric Acid.” These chemists proposed to treat Avignon madderwith a quantity of concentrated sulphuric acid equal to its own weight, oreven somewhat more. They thus obtain what they call charbon sulfurique , richm colouring matter, and fit for dyeing purposes after washing out the acid.This substance, however, has never been manufactured on the large scale, nor

* While direct sunlight is carefully avoided, even daylight is hardly admitted in these places,a nd a too great damp, as well as too great heat, are considered injurious, but extreme cold isequally avoided. Care is taken now and then to move the casks, i.e., roll them aboutthoroughly.

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