HORN. The weapons which project from the heads of various species of animals, constituting what are known as horns, embrace substances which are, in their anatomical structure and chemical composition, quite distinct from each other ; and although in commerce also they are known. indiscriminately as horn, their uses are altogether These differences in structure and properties are thus indicated by Professor Owen :--" The weapons to which the term horn is properly or technically applied consist of very different substances, and belong to two organic systems, as distinct from each other as both are from the teeth. Than the horns of deer cons:st of bone, and are processes of the frontal bone; those of tie giraffe are independent hones or epiphyses' covered by hairy skin; those of oxen, sheep, and antelopes are apophyses ' of the frontal bone, covered by the corium and by a sheath of true horny material; those of the prong-horned antelope consist at their basis of bony processes covered by hairy skin, and are covered by horny sheaths in the rest of their extent. They thus combine the character of those of the giraffe and ordinary antelope, together with the expanded and branched form of the antlers of deers. Only the horns of the rhinoceros are composed wholly of horny matter, and this is disposed in longitudinal fibres, so that the horns seem rather to consist of coarse bristles compactly matted together in the form of a more or less elongated sub-compressed cone." True horny matter is really a modified form of epidermic tissue, and consists of an albuminoid principle termed "keratin." It forms, not only the horns of the ox tribe, but also the hoofs, claws, or nails of animals generally, the carapace of the tortoises and the armadilloes, the scales of the pangolin, porcupine quills, and birds' feathers, 4,:c. The principal application of horns is for the manufacture of combs, and under the heading COMB, vol. vi. pp. 177-78, that industry is described. The other uses to which horn is now devoted, among which may be noted the pressing of buttons, the making of handles for walking-sticks, umbrellas, and knives, the manufacture of drinking-cups, spoons of various kinds, and snuff-boxes, do not here require ex. tended notice. The parings and refuse of horn are valuable for the manufacture of prussiate of potash and as manure; and the ash of the cores of horn makes excellent cupeis for the assay of precious metals. [n former times horn was applied to several uses for which it is no longer required, although such applications have left their traces in our language. Thus the musical instruments and fog signals known as horns indicate their descent front earlier and simpler forms of apparatus made from horn. To the same way powder-horns were spoken of long after they ceased to be made of that substance ; to a small extent lanterns still continue to be "glazed" with thin transparent plates of horn, a practice which a century ago was universal. Hornbooks consisted of spelling-books with their leaves protected by thin plates of horn, and it was in former times customary to protect the titles of valuable MSS. in the same way. Deer-horn is almost exclusively used for handles by cutlers and walking-stick and umbrella makers. The largest supply is obtained from the East Indies, and consists principally of the antlers of the axis, Axis maculata, and the Rosa (leer, Pusa A ri,stot el is.