(For 1 lb.) Enter in one bath 1 oz. Cutch, in another 1/2 oz. Chrome. Enter cotton in cutch bath, boil 20 minutes, wring out, boil 10 minutes in chrome bath. Add 6 oz. fustic or 1 oz. flavin to cutch bath, re-enter cotton. Repeat above until the required depth of colour is reached, finish in cutch bath to obtain deepest shade, which may be darkened by adding 1 drachm or so copper sulphate. A greyish drab may be got by adding ferrous sulphate. All shades of brown may be obtained by decreasing or increasing the amount of cutch or by adding a little logwood or fustic, in which latter case the cotton should have been previously mordanted. (9) BLACK (For 1 lb.) Wash, steep overnight in hot solution of tannic acid, 1 oz., wring out without washing, work for 10 minutes in soda bath, at a temperature of 50 deg. to 60 deg.C., 1-1/4 oz. Wring out, work in cold solution of copperas, 1-1/4 oz., for 1/2 hour, return to soda bath for 1/4 hour. Wash, dye in bath of logwood 12 oz., madder 2-1/2 oz., and fustic 8 oz. Enter into cold bath and raise gradually to boiling, boil for 1/2 hour, pass through warm solution of chrome, 1 oz., wash, work through warm soap bath. Greys may be obtained with 1 to 5 per cent of logwood after mordanting in a weak solution of iron. THE ZINC-LIME INDIGO VAT _The Zinc-lime Indigo Vat._ It will be necessary to explain these words--Indigo blue is insoluble and cannot be used for dyeing. If however it is "reduced" or changed to indigo white, it has, while it is in this form, an affinity for vegetable and animal fibre. These fibres will take it up from the solution and retain it. If they are then exposed to the air, the oxygen acts upon the indigo in the fibre and turns it back again to indigo blue. Various chemicals can be used to reduce indigo blue to indigo white. I propose to describe how the work is done with zinc dust and lime as reducing agents. In course of time the word "vat" has been transferred from the dyeing vessels themselves to their contents; _i.e._, the indigo dye liquor. By "vat," therefore, we understand not only the vessel used for dyeing indigo, but the solution of alkali salts of indigo white in water. This definition distinguishes the _indigo vat_ completely from indigo extract, or any other improper purposes to which indigo may be put. The zinc lime indigo vat is better than any other for dyeing cotton and linen. It is also very good for dyeing silk. It has many advantages over the hydrosulphite vat, as it is not nearly so much affected by changes of temperature and weather. It can be put to work after a six months' rest. The disadvantage which it shares with the copperas vat, though in a less degree, is that there is a sediment which must not touch the stuff during the dyeing. This is avoided by hanging a net in the vat after the sediment has settled, or by dipping the skeins on rods.