Even a blue-ground is, according to some, dyed afterwards in a decoction of logwood and galls, or logwood and sumach, and two pounds of verdigris for a hundred pounds of cloth. Thus, ten pounds of logwood and ten of galls, are to form the decoction, and are boiled previously for twelve hours. One third of it with the verdigris is used first, and then the cloth, after boiling in it for two hours, is aired; it is then passed through one third more of the decoction of logwood and galls, having previously had eight pounds of sulphate of iron dissolved in it, and the scum arising from the solution taken off. The goods are to be worked in this one hour at a boiling heat, then aired again by turning them about on a stone floor. The remainder of the decoction of logwood and galls is then added, with fifteen or twenty pounds of sumach; boil it some time, and then add five pounds of sulphate of iron; scum it, and let the liquor cool down, then put the goods in, and work them at a boiling heat an hour or two, taking them out once or twice, at least, in the time, to air and cool; they are then to be well washed, and passed through a decoction of weld liquor, to soften the black, which will be very fine. This process is chiefly from _Hellot_; but the quantity of sulphate of iron is more by three pounds than he directs. When the cloth is blue, it is usually boiled two hours in a decoction of galls, then washed and aired, when sulphate of iron and logwood are added to the liquor, and the goods worked in it for two hours, and then washed. The above have been the processes in practice for a century past in France, where the galls were not so dear as they now are in England: sumach is here, therefore, now most commonly used as a substitute for galls. _Another process for_ BLACK _without a blue ground._ To dye one hundred weight of cloth, take thirty pounds of chipped logwood, half a bushel of alder-bark, and six pounds of sumach, and boil them together in a proper quantity of water for half an hour; then cool the decoction down with cold water, enter the cloth, turning it on the winch; bring it to a boil, having the sumach in a bag; boil and keep the cloth turning for one hour and a half: this is the ground. Have now ready fourteen pounds of sulphate of iron dissolved in water, which is to be laded into the copper by one man, while another turns the cloth for an hour at a boiling heat; it is then to be taken out, cooled, and aired, returned to the copper, and boiled gently for two hours, and then cooled again. While the cloth is cooling, six pounds of logwood, ten pounds of alder-bark, two pounds of argol, ten of soda, or common pot-ashes, and three pounds of sulphate of iron, are to be added to the liquor in the copper, and boiled one hour, when the goods must be turned and worked one hour; and, lastly, taken out and aired. This black is said to be of the hue of a raven's feather. _This process is from_ HEIGH.