Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 2, 1802).djvu/234

204&#93; !04] I) y r. of the n era- f loved, and the fn '■■••■ : ' pre- pari o^ a sol u don n' l«n which is the onlv ingfgdte&t by winch that delicate colour can be produced. To eight ounces of gpmt 61 nitre an equal qiantilv of river-water is 10 be added ; in b&s mbo'nv are to be I half- an ounce of the purest and whites* sal-ammoniac, and tv/o drains of purihcd saU-pt oo. Ah ounce of tin, reduced to grains-, by b pfed into cold water melting, is in -:i to be added drop by drop to the liquor thtis pr. pared ; the first being perfectly dissolved before a second is introduced. The solution resembles that of gold, and, iffinetinbe employed, will be perfectly transparent, without any dust or sediment. "With this liquor are to be mixed such pro- portions of cochineal as may he thought proper, and the stuffs dyed in the colour will acquire a most beautiful scarlet. The scarlet produced by gum luc, though not so bright as cochineal, is more permanent 5 the best lac is that which is of a blackish brown colour on the oui.sl.Se, and v within. The process of preparing this colour is very difficult j but the best method, we believe, is that of previously mixing the gum with eomfrey, or other mucilagi- nous roots. These should be dried, finely pul fter* ards boiled for fifteen minutes in the propor- tion of half a dram to a quart of water, then strained through a li- nen cloth while hot, poured wy.im levigated gum -lac, and p. '.-sod through a hair sieve. The whole is then digested in a moderate heat for twelve hours ; and the gtu 1 re- maining at the bottom should be stirred seven or eight tunes, The D Y E, is afterwa ed ire - ;. sufficiently cious to hold four times Hie r< My, and hlled up with cold water. Q n adding 3 small eor/, tion cf SI strong solution at alum, the co- loured mucilage subsides ; and, should any tinge remain in me li- quor, it may be precipitated by gradual additions of alum, till it become peril-cily colourless. As soon as ikre crimson mucilage has entirely subsided, the clear water must be catefaliy decanti maindcr filtered, and the Said parti suffered to evaporate. If the whole of the colour should not be e>:tra6t- ed. by the first operation, it ought to be repeated, till the residuum changes to a pale straw-colour. In order to dye scarlet with this extract of gum-lac, the requisite proportion of the latter dried and pulverized, is to be put into an earthen or block-tin vessel 5 a little hot water poured upon it ; and, when it is well moistened, a proper quantity of the come I ted ; the whole being stirred with a glass pes do. By this means the powder, which before was of a dark, dusky purple, acquires as exceedingly . scarlet colour. A solution of the crystals of tartar is then to be poured into the liquor, ainl a& soon as it begins bo boil, the cloth is to be repeatedly immersed in it, according to the common method. The. remainder of the operation is. to be performed in the same man- ner as if cochineal had been em- ployed. L'rr,vsov is the colour produced by cochineal, with nkira and tartar only. wit ! out any solution of tin. For this dye. two ounces and a half of alum, with an ounce and a half of white tartar, art to be taken, for ewy