HORN. The projecting weapons on the head of the ox, the sheep, the antelope, and the rhinoceros, consist of a sheath of horn on a core of bone. Horn is composed chiefly of coagulated albumen, gelatine, and a small portion of phosphate of lime. It is essentially distinct from bone and
Horn. ivory; the antlers of the stag, although sometimes called horns, consist entirely of bone. Modifications of horn may be noticed in the scales of the armadillo, the plate armour of the tortoise, the spines of the porcupine and hedgehog, the quills of birds, and the hoofs, claws, and nails, of animals. For manufacturing purposes, the horns and hoofs of the bull and cow are in request, and there is a large import of these from South America, Southern Africa, and from Russia. The horns of the bison and buffalo, the chamois and the antelope, are used for the better kinds of work.
The manufacturer first detaches the horn from the bony core, by macerating the horn in water for a month or six weeks, when the membrane by which the horn is attached to the core putrifies and allows the two to be separated. The ash of the cores makes excellent cupels for the assay of gold and silver. The solid tips of the horn are sawn off, and are used for handles for knives, for buttons, &c.; the other portion of the horn is cut into short lengths, or soaked whole in boiling water, or heated at a fire, the effect of which is to soften it, and allow it to be spread out nearly flat. The flats are next pressed between warm and greased iron plates, the pressure varying according to circumstances. If intended for lanterns, the pressure is continued until the horn separates into distinct plates; these are placed on a board covered with hide, and scraped with a knife having a wire edge. Some of the shavings which come off are sometimes dyed and cut into various forms, and are so sensitive as to curl up by the warmth of the hand. They are sold at toy-shops under the name of "sensitive leaves." After the scraping, the sheets of horn are polished with a woollen cloth dipped in charcoal dust and water, next with rotten-stone, and lastly with horn shavings.
The effect of heat and pressure on light-coloured horn is to render it transparent; but most of the articles made of horn are coloured artificially by boiling the horn in infusions of colouring matter. If the horn be intended for combs, the pressure must be moderated, or the teeth will be brittle; if intended for drinking cups, the horn is cut into lengths, scalded, roasted, and moulded in a cone of wood, and a wooden plug is driven into it for pressing the horn into the required shape. After this, the cup is turned and polished at the lathe, and a groove is cut to receive the bottom; this is cut out of a flat piece of horn by means of a crown saw, and the bottom of the cup having been softened at the fire, the disk is forced into the groove, and the horn contracting in cooling makes a water-tight joint. For knife-handles and similar works, the horn is cut nearly to the required form, and is moulded in dies with the assistance of heat and a powerful screw-press. The work is finished by scraping and buffing with Trent sand and oil, or rotten-stone and oil. Horn is sometimes used as a vehicle for applying polishing powders to the flat works of the watchmaker. In the Great Exhibition of 1851, there were sundry small articles of chamois horn, consisting of brooches, shirt-buttons, rings, and watch-keys, by a Swiss exhibitor; there were also some transparent horn paintings from Hamburg, and a pair of polished ox-horns from Port Natal, with the head complete, measuring from tip to tip 8 ft. 4 in., and 21 in. in circumference. The best collection of articles in horn-work was, however, from Turkey. See TORTOISE-SHELL. (C. T.)