Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/55

37&#93; ISI EtJck, till the pockets ■come ont easily., so tiiat they preserve the sound entire. This .isinj^Iass is dried upon nets in the open air, and resolves into fining Hke that of Rivssian manufacture, in sub-acid liquors, such as stale beer, cyder, oid hock,&c. while, in equal quan- tities, it produces similareffetts up- on, turbid liqu(>rs, except that it falls sooner and closer to the bot- tom of the vessel 5 though foreign isinglass, on account of the greater tenacity of its native mucilage, re- tains the power of lining preferably in warm weatiier. With respect to the xery exten- eiv< use that is made of isinglass by brewers, and wine-merchants, we have aireadv express, d our disap- probation, under the hcadof Cla- BiFiCATioN; and also recommend- ed proper substitutes, vol. i. p. 239, especially as H.Jacksox informs us, in his Essays on Britishlsingluss, published about the year 1/65, that its yearly consumption in the brewery was then calculated at 25 tons weight, and that 40,0001. an- nually are paid for this article to the Ku'.sians. Hence it is sincerely to.be wished, that this importation may be enLirely superseded, as there is an adequate supply from the British colonics. I'he iinest and most IratLsparent sorts of isinghiss are consumed in making mock-pearls, and in stif- fening linens, silks, gauzes, •&c.— It may likewise be reduced to 3 jelly, as it dissolves in aikahne li- qiiors j and even cold lime-water converts it into a pulpy mass.^ Al- thpu^h such preparation w ould be extremely detrimental to health in fining liquors, yet it may be use- fully employed .tor another pur- .po-ie ; because, on mixing this jelly Willi CQinuosilions of plaster, lime, I S S [37 ^'c. for ornamenting walls exposed to vicissitudes of weather, it forms a hrm and durable cement ; and, it worked up with common mortar, it soon acquires the harshness of bricks. With tliis intention, how- ever, it is more conveniently pre- pared by dissolving it in cold wa- ter, acidulated with oil of vitriol : thus, the acid quits the jelly, and forms with the lime a selenitic mass ; while the jelly, being de- prived of part of its moisture, speedily dries, and hardens into a hrm body ; whence its superior strength and durability may b« easily explained. In a medicinal view, isinglass is but seldom employed; though it may with advantage be used in violent bleedings from the nose, by intro- ducing into the nostril a pessary made of soft hnen, and dipped in a solution of this glue, prepared in equal parts of spirit of wine and water. Isinglass also forms a prin- cipal ingredient in sticking-plaster; and, when boiled in fresh milk to the consistence of a strong jelly, it affords a very nourishing food to invalids ; though it should be eaten with precaution by those who pos- sess a weak stomach, or digest slowly J as it has a great tendency to turn rancid and putrid. ISSUES, are small artilicial aper- tures or ulcers in the muscular parts of the body, for the purpose of draining superfluous moisture, or of giving vent to some noxious humours. Issues are usually made in the arm.s, legs, or back, either by caus- tics, or by incision. They are cliief- ly applied in disorders of the head, eyes, ears, teeth, Sec. which are thus relieved, and frequently cured. Inveterate complaints generally re- quire two ormore issues, toproducc J3 3 and