GARANCINE, a manufactured product of madder; hence its name, derived from the French garance. The discovery of the process for making this material is due to the French, and it has proved one of the most valuable additions to our dyeing materials that has been made during the present century.
It was first practically used in the dyeing establishment of Messrs. Lagier and Thomas at Avignon,•here it was introduced with the hope of turning the spent madder to account; but the rude manner in which it was prepared prevented it from becoming generally used for a long time, and our ignorance of the organic chemistry of madder at first hindered its improvement. It was first prepared by drying and pulverizing or grinding the spent madder which had been used in the ordinary processes of dyeing madder styles; this was then saturated with sulphuric acid, which was supposed to char the woody tissue, and destroy the alizurine and some other- organic products of the madder, but to have no effect upon the purpurine, which was consequently available for fresh dyeing processes. Subsequent experience showed these views to be wrong,
and G. is now prepared for pure ground madder-root which has not previously been used. • For this purpose, the ground madder is mixed with water, and left for a day, and then fresh water is added, and the •whole drawn off. By this means, the sugar, and probably the whole of the rubian, another principle of the madder, are dissolved and removed. Sulphuric acid is then added, and the temperature raised to about 90° F. for some hours, after which it is well washed with cold water, strained, pressed, and dried, and afterwards ground. In this state, it has a fine chocolate-brown color, and looks somewhat like ground coffee. The advantages of G. over madder are, that it is more easily used, and the colors it gives are brighter and more intense, although not so per manent.