652

HORN.

HORDEINE is the name given by Proust to the peculiar starchy matter of barley. ^seems to be a mixture of the starch, lignine, and husks, which constitutes barley meal-See Beer.

HORN (Eng. and Germ.; Come, Fr.), particularly of oxen, cows, goats, and sheep> 1Sa substance soft, tough, semi-transparent, and susceptible of being cut and pressed intovariety of forms; it is this property that distinguishes it from bone. Turtle or tortots (shell seems to be of a nature similar to horn, but instead of being of a uniform color,is variegated with spots.

These valuable properties render horn susceptible of being employed in a vartc Jof works fit for the turner, snuff-box, and comb maker. The means of soften 1 ®^the horn need not be described, as it is well known to be by heat; but those ofpolishing, and soldering it, so as to make the plates of large dimensions, suitableform a variety of articles, may be detailed. The kind of horn to be preferredthat of goats and sheep, from its being whiter and more transparent than the h° ,of any other animals. When horn is wanted in sheets or plates, it must be s tee Pin water, in order to separate the pith from the kernel, for about fifteen days in sU ^mer, and a month in winter; and after it is soaked, it must be taken out by one e >well shaken and rubbed, in order to get off the pith; after which it must be P u *half an hour into boiling water, then taken out, and the surface sawed even, ^ eB ~^ eways; it must again be put into the boiling water to soften it, so as to render it cap aof separating ; then, with the help of a small iron chisel, it can be divided into sheetsleaves. The thick pieces will form three leaves, those which are thin will form ° ne _two, whilst young horn, which is only one quarter of an inch thick, will form only 0 ^These plates or leaves must again be put into boiling water, and when they are suffimPsoft, they must be scraped with a sharp cutting instrument, to render those parts tha ^thick even and uniform; they must be put once more into the boiling water, and h ncarried to the press. i • h

At the bottom of the press employed, there must be a strong block, in '" r ' llC j )0r nformed a cavity, of nine inches square and of a proportionate depth ; the sheets olare to be laid within this cavity, in the following manner at the bottom : first a she ^hot iron, upon thig a sheet of horn, next again a sheet of hot iron, and so on, takmr ^to place at the top a plate of iron even with the last. The press must then be sodown tight. into

There is a more expeditious process, at least in part, for reducing the hor r p

sheets, when it is wanted very even. After having sawed it with a very fine andsaw, the pieces must be put into a copper made on purpose, and there boiled, untr j nciently soft, so as to be able to split with pincers; the sheets of horn must then he P j ( . 0 nthe press, where they are to be placed in a strong vice, the chaps of which areand larger than the sheets of horn, and the vice must be screwed as quick and ■ Teolipossible; let them cool in the press or vice, or it is as well to plunge the whole 1 j^ 0 wwater. The last mode is preferable, because the horn does not shrink in cooling- r 0 ( . es s.draw out the leaves of horn, and introduce other horn to undergo the same I ^jehThe horn so enlarged in pressing, is to be submitted to the action of the sa' > in

ought to be set in an iron frame, if the horn is wanted to be cut with ad van -sheets of any desired thickness, which cannot be done without adopting this m® ‘ f hotthin sheets thus produced must be kept constantly very warm between P a en 0 u2h 10iron to preserve their softness; every leaf being loaded with a weight heavy neces satyprevent its warping. To join the edges of these pieces of horn together, it i s , gce tl> eto provide strong iron moulds suited to the shape of the article wanted, and t 1 w he®pieces in contact with copper-plates or with polished metal surfaces against tn Lj inf®this is done, the whole is to be put into a vice and screwed up tight, then P j jn col“boiling water, and after some time it is to be removed from thence and imme - p er fec ( "water. The edges of the horn will be thus made to cement together and beco

ly united. euhni trate °’t

To complete the polish of the horn, the surface must be rubbed with the S1 Cj th at 1bismuth by the palm of the hand. The process is short, and has this advan ?makes the horn dry promptly. ,,; c s£>l llll °^ e

JVhen it is wished to spot the horn in imitation of tortoise-shell, metn „)ustmust be employed as follows :—To spot it red, a solution of gold, in aqua re.^’. andemployed; to spot it black, a solution of silver in nitric acid must be 1 - I n us L.i iebrown, a hot solution of mercury in nitric acid. The right side of the jgj. gimpregnated with these solutions, and they will assume the colors m wit' ^

brown spots can be produced on the horn by means of a paste made oi re _ oro e tij °f a fsolution of potash, which must be put in patches on the horn, and subjec guantdJ

the action of heat. The deepness of the brown shades depends upon A

potash used in the paste, and the length of time the mixture lies on J. n 0 f sad 1coction of Brazil wood, or a solution of indigo, in sulphuric acid, or a deo