The roots and bark of _Berberis Vulgaris_ is used principally for silk dyeing, without a mordant. The silk is worked at 50 deg. to 60 deg.C. in a solution of the dye wood slightly acidified with sulphuric, acetic or tartaric acid. For dark shades mordant with stannous chloride. _DYER'S BROOM_ _Genista Tinctoria._ The plant grows on waste ground. It should be picked in June or July and dried. It can be used with an alum and tartar mordant and gives a good bright yellow. It is called greening weed and used to be much used for greening blue wool. _PRIVET_ _Ligustrum Vulgare._ The leaves dye a good fast yellow with alum and tartar. _HEATHER_ Most of the heathers make a yellow dye, but the one chiefly used is the Ling, _Calluna vulgaris_. The tips are gathered just before flowering. They are boiled in water for about half-an-hour. The wool, previously mordanted with alum or chrome according to the shade of yellow wanted, is put into the dye bath with the boiling liquor, which has been strained. It is then covered up closely and left till the morning. Or the wool can be boiled in the heather liquor till the desired colour is obtained. _ONION SKINS_ Prepare by mordanting with alum. Take a sufficient quantity of onion skins and boil for 30 minutes. This gives a good yellow. The addition of tin will make the colour more orange. CHAPTER VIII BROWN AND BLACK CATECHU ALDER BARK SUMACH WALNUT PEAT SOOT LOGWOOD AND OTHER DYES _CATECHU_ Catechu (Cutch) is an old Indian dye for cotton. It can also be used for wool and silk, and gives a fine rich brown. It is obtained from the wood of various species of Areca, Acacia and Mimosa trees. Bombay Catechu is considered best for dyeing purposes. Catechu is soluble in boiling water. It is largely used by the cotton dyer for brown, olive, drab, grey and black. (See pp. 46, 47, 48.) LIGHT GREY (For 6 lbs.) 1 oz. cutch, 1 oz. iron. Boil for 1/2 an hour in the cutch, then put into boiling iron, being very careful to stir well. Wash very thoroughly. These proportions can be varied according to the shade of grey required; the more iron makes the colour browner, the more cutch the bluer grey. CATECHU BROWN The wool is boiled for 1 to 1-1/2 hours, with 10 to 20 per cent catechu, then sadden with 2 to 4 per cent of copper sulphate, ferrous sulphate, or chrome, at 100 deg.C., in a separate bath for 1/2 hour. _ALDER BARK_ The bark and twigs of alder are used for dyeing brown and black. For 1 lb. wool use 1 lb. alder bark. Boil the wool with it for 2 hours, when it should be a dull reddish brown. Add 1/2 oz. copper as for every pound of wool for black. _SUMACH_ Sumach is the ground up leaves and twigs of the _Rhus coraria_ growing in Southern Europe. It dyes wool a yellow and a yellow brown, but it is chiefly used in cotton dyeing. _WALNUT_