While expense is not an object, it is best, not only for yellows, but for all other colours, to have the preparation and the dye proportioned to the shade, the colour done at once, and the remaining liquor thrown away; but as the price usually paid for dyeing will not enable the dyer so to do, he commonly dyes his shades in succession, as above, and with the utmost economy. _To dye wool_ BROWN, _or of a_ FAWN COLOUR. These shades are extremely various, and are dyed without any preparation with alder-bark, red sanders, sumach, galls, madder, &c. and under a boiling heat, although it is occasionally necessary to boil some of the ingredients together previous to the dyeing: for instance, red sanders will give its colour out best when boiled with galls, alder-bark, sumach, &c. Cam-wood, bar-wood, walnut rinds, roots, &c. are used in some of these shades, the varieties of which are almost infinite. Practice is required in this branch of dyeing equal to or beyond any other. _To dye wool_ PURPLE, _&c._ Pass the goods through _archil_, next through the _blue vat_, with the usual precautions, then through hot water. For some shades they should be alumed, and then dyed with cochineal for the crimson part of the purple. _Blue_ and _crimson_ make purple, violet, &c. according to the patterns required. _To dye wool_ GREEN. The shades of this colour are very numerous, as _yellow_ green, _pale_ green, _bright_ green, _grass_ green, _laurel_ green, _olive_ green, _sea_ green, _parrot_ green, _cabbage_ green, _duck's-wing_ green, &c. The goods must first have a blue ground from the woad vat, light or full according to the pattern, they are afterwards to be prepared with alum and tartar, weak or strong according to the lightness or fulness of the pattern, and are afterwards dyed in weld liquor. Many of the shades of green are more readily done by dyeing the wool first yellow with old fustic, with a preparation of alum and tartar, and using the chemic blue vat made with sulphuric acid and indigo. See page 47. _A chemic vat for_ GREEN WOOLLEN. Prepare in the manner described for cotton (page 52.), eight ounces of indigo and four pounds of sulphuric acid. This preparation need not, however, be neutralized for wool as described for cotton. In some instances the preparation is to be for the yellow of fustic one-twelfth of alum, the same quantity of tartar, and in some cases one-twelfth of alum only. _A chemic vat for_ BLUE WOOLLEN.