_To dye cotton skein a_ DUCK'S WING GREEN _and_ OLIVE. This is performed by a blue ground, next galling, dipping in the black vat, then in the weld dye, then in verdigris, remembering to wash off previously to performing each process. _Olive_ is to be performed with weld or old fustic, verdigris, and Brazil wood. _Of_ BROWNS, MAROONS, COFFEE-COLOURS, _&c._ It would answer little purpose to enlarge this treatise with a detail of all the possible methods of producing the various shades of these several colours, the whole consisting in the use of galls, verdigris, sulphate of copper, weld, and madder. By welding a stuff previously maddered for _red_ you may produce a _gold_ colour; and by dipping the same red in a blue vat you obtain a _plum_ colour. _Observations on_ SILK. Silk, as it is obtained from the cocoons of the worm, is generally of an orange or yellow colour, more or less dark; in the South of France it is generally very dark: its natural shade is unfavourable to almost all other colours. It is also imbued with a kind of varnish or gum, which makes it stiff and hard; this stiffness is improper in the fabrication of most silk stuff, it is therefore _ungummed_, as it is called, by the following processes. _On ungumming and boiling silk._ _Observe_, that throughout the following processes for silk _white_ soap is directed to be used; and, generally speaking, we believe it will be found the best, more especially for the more delicate operations. Yet _Mr. M'Kernan_, in his process for ungumming silk, directs yellow soap and soft soap in equal parts, and of the same weight as the silk to be used: he adds, however, that different sorts of silk require more or less soap; the best rule he finds, nevertheless, is _the same weight of soap as of silk_: and he says also, that yellow soap and soft soap of the best quality he finds the best for this purpose. The silk is divided into hanks, each hank is tied with a string, several of these are tied together (a handful of them) by putting a piece of string through each separate skein, and tying the piece of string in a long tie to slip easily when they are wanted to be untied. A liquor is prepared of thirty pounds of _white_ soap to a hundred pounds of silk; the soap is cut into small pieces and boiled in water, when it is dissolved the fire is damped. While the liquor is preparing the skeins of silk are put on rods; as soon as the soap liquor becomes a little below boiling heat (for it should not boil, as boiling would tangle the silk) the silk is to be put into it in an oblong copper, being nearly full; it is to remain in the liquor till its gummy matter has left it, which will be seen by its whiteness and flexibility. It is then turned end for end on the rods, that the part above the liquor may undergo the same operation. As soon as this is accomplished the silk is taken out of the copper, the hanks which were first turned being soonest done.