NATURE AND SERVICE OF Hons. Horn is the connective tissue of the epidermis hardened and thickened, and in some cases mixed with, or composed of, agglutinated hairs. Its purpose is to form a resisting or protective surface, or a tough tool or weapon. The whole, or principal part, of the epidermis may become of this nature, as is the case in the hide of armadillos and the scaly ant-eaters, ancient and modern, in serpents and lizards (whose scales are horny), and in the turtles which supply tortoise-shell I q.v.). In the higher ranks it constitutes the 'whalebone' developed from the palate of the baleen-bearing whales; becomes the protective sheath of the mandibles forming the serviceable beaks of birds and turtles; and, by more or less completely en sheathing and extending the outermost hone of each digit, forms nails. claws, and NAIL), strengthening and arming the fingers and toes of such reptiles as have feet, of all birds, and of all the mammals except whales. Horn enters also into spurs on the legs and other parts of certain animals. forms one or more shields, or weapons. or both, on the head: and callosities elsewhere, such as on the heel of man (and the `corns' on his toes), the knees of camels. etc.. as use and habit call for a hardening of the cuticle to resist, wear and relieve pressure. Further particulars as to these structures will be found in the article BIRD (the beak) ; INTEGUMENT: NAIL (nails, claws, hoofs. spurs. etc.) : TON; SNAKE (scales, rattle, etc.) ; TourotsE SuELL: TCRTIE: and Hader BORN!, The chemi cal composition of the various horny tis-ues is exhibited in the table on the follo‘‘ing page.
These tissues differ slightly in the quantity of inorganic matter which they contain. but the difference does not vary much beyond 1 per cent. Hair yields from 0.54 to 1.35 per cent. of ash. containing among other ingredients, peroxide of iron and a little silica. In feathers. the quantity of silica is very considerable, and it is doubtless to this constituent that the shaft in a great measure owes its strength and hardness.
lloaxv Tisst c appears a variety of tumor upon different regions of the human skin, but espet tally 'quill the face, and occasionally in dertnoid ,\--ts. These manitestations are con sidered a, of 1,11tch the epidermal cells are intifnatel united in the same manner as in the nails; and they are classed with warts, corns. and some na•vi, under the term corneous pupil mama. The tendency to horny on the skin is rare, and belongs to advanced age. There is a disease of the skin called which is a peculiar variety of papillary hypertrophy. with hornifying of thus way it is employed in making handles for umbrella,, knives, forks, and a variety of tither Combs are made out of the flattened sheets. and beautiful carvings are made out of the solid parts of bulfalo-horns. Ux-horns, too, are :sometimes of tine quality and color, and are fashioned into drinking-cups and other articles, often highly ornamental. Before the horn is
softened for manufacture. the solid tip is usu ally sawed off, to be treated separately. This is usually sawed into blanks to be used tor buttons and other purposes. 'rinse blank, are heated, pared, heated again in xratcr and pressed between the epidermis of such a nature that it. re short 'Horny exeres eences occasionally break and fall off spou t-moat*: but they grow again if not cured radically by the excision of the portion of skin Upon which they are located.
EcoNomit• Uses HORN. The horns of ani mals enter largely into the manufacture of many useful and ornamental articles, and are employed tor useful and ornamental purposes. The prin cipal horns employed are those of the ox. buffalo, sheep, and goat. 'These are quite different in structure from the of various deer, which arc really bone and resemble ivory in structure. More like true horns are hoof, and quills. Horns have but 2 or 3 per cent. of earthy matter, while have over 50 per cent. Horn can he softened 111141 split into thin layers or lamina.. or pressed into mold:. it recovers its peculiar character of flexibility. toughness, and transparency when gold. it is particularly adapted for a great variety of purposes. It can be dyed various colors. A solution of gold in aqua regia dyes it red; a solution of nitrate of silver in nitric acid. black; a paste of red lead, made with a solution of potash, colors it brown: .11 Olt with a proper arrangement and application of these the most admir aide in it it ions of the much 1114 ire eostly tortoise shell can be produced. which. indeed, it resembles in structure. The more common vegetable dye stuffs, as log-wood, 13razilwf,041. barwood, saffron, 111', will also color horn, hut neither so permanently Ina- so brightly as the metallic ma By long-continued soaking. the horns of all the animals above mentioned Pan be softened, and those of the sheep :Ind goat can easily he split into several layers after they have been soaked and boiled. These ran not only be flat tened out by putting them between smooth iron heated and placed in a press. but can be welded together firmly by pressine. their edges to gether between polished copper plates, and then plunging them for some time into boiling water and then into cold water. This property enables the horn-worker to use up the smallest cuttings with profit. Another valuable property of horn is that when heated it can be pressed into a die, and not only take: a beautiful sharp impression. but if left in the die until cold it retains it. In dies. atter which they are buffed and polished. The value of the horns and hoofs imported into the United States to be consumed in domestic manufactures in recent years has been as follows: 1s93. 554.902; 1894, 1895, $268,s00; 1s96, :icitiS.4.15; 1897, $150,134.