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DYEING AND CALICO PRINTING.

In 1846 and 1847 Roux patented the application of fermentation to madder toobtain thereby a peculiar preparation. This process was found very capricious,since the temperature, the duration of the steeping, the quantity, and also thequality of the water so much affedt the results that a slight change in any ofthese particulars is enough to render the madder useless.

Julian and Roquer describe their own process thus :—We take madder rootsand reduce these to powder; the madder thus obtained is placed in tanks, and,after the addition of water, is thoroughly and vigorously stirred up with thatwater, which we take cold or hot, and which we treat according to its degree ofpurity with any acid to eliminate its contained lime-salts. We then run the entirecontents of the tanks into the filtering boxes, consisting of stout woodenframes, lined with flannel; the bulk of the liquid is suffered to run off, and,according to the product we desire to obtain, we leave the madder in theseboxes for a length of time, varying one to five or six days, according as itsuits our purpose to produce alcoholic fermentation or not. The madder istaken from these boxes and put into stout linen bags, and strongly pressed bymeans of hydraulic presses of great power; the pressed cakes are dried instoves (heated by steam, and arranged similar to those of the sugar refineries),ground up to powder, and packed into casks. The liquids are either collectedfor fermentation or run off into the sewers; if fermented by the addition some-times of beer yeast, but chiefly by means of sufficient fermentation-inducing nitrogenous matter present in the liquors naturally, we submit thelatter to distillation and obtain alcohol. The first samples of their productwere sent in Januar3’, 1851, on trial to Mulhouse, and in February, 1852,Messrs. Julian and Roquer had sent off from their works at Avignon 300,000kilos, of fleur de garance. By the process described the madder loses half ofits weight of useless materials.

M. Pernod, of Avignon, has kindly given the writer the following informationon the more recent mode of preparing bloom of madder:—The madder ismixed with from eight to ten times its weight of river water (the less salinematter present the better), to which just so much sulphuric or hydrochloricacid is added as will saturate the carbonate of lime always present in thepulverised madder. When sulphuric acid is employed, from 1 to 2 kilos, ofthe concentrated acid are applied for every 100 kilos, of madder; the additionof the acid is chiefly made when it is intended to prepare a material particularlysuitable for the dyeing of red and brown colours, but when the preparation ofa material especially suited for violet dyeing is desired, no acid at all is used:this operation is done in a wooden tank, lined inside with stout flannel, whichrests on a false perforated bottom, between which and the real bottom a smallspace is left provided with one or more taps, so placed as to ensure therunning off the liquid when desired, while the pasty mass remains on the filtersupported by the false bottom. The madder is left macerating in the liquidfor about twelve or fifteen hours, when it is tapped off; and since this hastaken up the largest portion of the sugar present in the madder, it is run intotubs of suitable size and construction, and left to ferment, to be convertedinto alcohol by distillation. The pasty material which remains inside the tankis immediately taken out and placed in stout linen bags, in quantities of from3 to 4 kilos., and submitted to very strong pressure by means of the hydraulicpress, in order to remove the largest portion of the liquid; after which the