Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 2, 1802).djvu/232

202] DYE ing that time to observe it minute- ly, incase.it should cast Hue. The vat is then to be filled up with wa- ter, and a sufficient quantity of in- digo, dissolved in a ley of pot-ash; pure water, bran and madder. The vat being again covered, at the end of three hours a pattern is to be im- mersed in the liquor for a similar space of time, when it is to be taken out, to inspect the state of the vat. This pattern, when first taken out, should be of a green co- lour, but instantly turn blue; if the green be bright and good, the vat is to he stirred again, and covered up, with the additioi few handfuls of bran. Three ; after, the same operation is to be rep ated, with the addition of more bran, if necessary, when it is to be covered up for an hour and a half longer: and, as soon ash subsides, another specimen is to be immersed in it for an hour, when it must be examined, to ascertain the state of the pastel. If the former be of a good green, when fakeri out, and tarn suddenly to a deep Blue, on being exposed to the air, another pattern is to be put in, to discover the effect of the vat ; which, if the colour b - sufficiently high, is to be filled with hot water, or (which is preferable, if it can be procured), with the liquor of an old madder- vat, and then stirred again. Now the vat is to be once more covered for an hour ; after which the st to be iWtd should be immersed. Woad is the next article in the making of a blue colour : the mode of preparing it differs in no respect from the preceding one, just de- scribed, excepting that it is weaker, and yields less colour. Indigo is the last ingredient in dyeing blues. The rat is about 5 1 t high, 2 feet in diameter,, and some- D YE w'.at narrower towards the bottom., bring surrounded by a wall, and having a vacancy for the embers, A vat of this size requires from 2 to 5, or even Gibs, of indigo ; and this operation is conducted as fol- lows : i . About 15 gallons of river water are put into a copper to boil for about half an hour, together with 2 lbs. of pot-ash, 2 oz. of madder, and a handful of bran. 2. Immerse 2lbs. of indigoin apail of cold water, in o dtr to separate the solid from the volatile pai hkh will immediately rise to the surface. tne watery liquor is th.m poured oft* and the indigo, settled at the bottom of the pail, should be tri- turated in an iron mortar, with the addition of .entity of hot water, that ought lobe shaken from side to side; and the floating particles of indigo, which are f finely pounded, must be pour- ed into another vessel. In this manner, the : : idigo remaining in the mortar is continually reduced, fresh water being repeatedly added, till the whole is pulverized so fine- ly as to rise to the sufl The liquor which had, during the above stated preparation, been, boding in the copper, is now pour- ed into the vat, together with the indigo, when the whole is well stirred with a rake, the vat closely covered, and surrounded with em- bers. If this operation commence in the afternoon, the embers must be renewed in the evening, and also in the morning and evening of the following day, in the course of which it should be twice gently I. Similar measures ought to be pursued on the third day, in order to preserve ah uniform heat, and intimately mix the ingredients. A brassy scum will then be per- ceived to rise to the surface, in several