DYEING AND CALICO PRINTING.

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has also resulted in the detection of the existence of a combination of themordant and lime with the colouring matter, viz., if madder had been usedcontaining calcareous matters naturally, or if chalk had been added in thedye-beck.

All these observations refer to madder only. As regards fleur de garanceand garancin, irregularities in the mode of heating, the material used in theconstrudtion of the dye-beck, and many other conditions, have no prejudicialadtion upon the process of dyeing. Generally speaking fleur de garance canbe used instead of madder in all cases where clearing is required, but madderis preferable for the kind known as triple pink (rose-red); fleur de garance,

Fio. 22.

again, is suitable for purples and blacks ; for red and black a mixture of fleurand madder is used, which yields a deeper black than fleur by itself.

On the large scale madder dyeing is performed in well-construdted, water-tight, wooden tanks, heated by steam, and provided with properly contrivedrollers moved by means of straps so as to impart to the goods stretchedon these rollers a suitable motion, and thereby to cause a regular renovationof the points of contadt between the bath and the cloth. Fig. 22will give the reader some idea of this contrivance, which is also in use forthe dunging, branning, and soaping processes. As regards the practical