THE horns of animals have next to be considered, for which, says Mr. Aikin,
"In teh English lauguage we have only one word to express two quite different substances; namely, the branched bony horns of the stag genus, and the simple laminated horns of the ox genus, and other kindred genera."
"The bony horns are called in the French bois, from their likeness to the branch of a tree: they are annually renewed."
"The other sort of horn to which the French appropriate the term corne, and which is the subject of our present inquiry, is bond on the ox, the antelope, the goat, and sheep kinds.*"
These two kinds will be considered separately.
The stag-horn closely resembles the ordinary solid bones, both in its chemical characters, and also in structure, as it is spongy and cellular in its central parts. The horn is sawn into pieces, filed to the required shapes, and used without any further preparation, the natural rough exterior of the horn being left in the original state; its appearance is neat and ornamental, and from its uneven surface is very suitable for the handles of knives, and other instruments requiring to be held with a firm grasp.
When short pieces of stag-horn are used entire, as for the handles of table-knives, the hollow cellular part is concealed by the addition of the metal cap, and those parts of the white internal substance, which are necessarily exposed, are browned with 1 hot iron, or the flame of a blowpipe, so as nearly to match the other parts. The deer horns are imported from Ceylon and Bombay, and the finest from Germany. See Appendix, Note M. p. 957, Vol. ii., on straightening stag-horn and buck-horn.
The horns of the ox tribe are deposited in annual layers upon the bony cores that project from the foreheads of the animals;
* Trans. Soc. of Arts, Vol LII., Part 2, p. 334.
whence it results, that the general form of the horn, (neglecting its curvature,) is conical, the portion beyond the core is solid, and the other extremity tapers off so as to terminate at the base in a single plate, or extremely thin edge.
Horn consists almost entirely of animal matter, chiefly membranous, namely coagulated albumen with a little gelatine, and an inconsiderable portion of phosphate of lime: had the horns much more earth they would be brittle like bones, had they much more gelatine they would be soluble like jelly or glue; as they are constituted, the quantity of gelatine is only sufficient to allow them to be considerably softened by a degree of heat not exceeding that of melted lead, after which they may be cut open with knives or shears, flattened into plates, divided into leaves, and struck between dies like metal. Their gelatine serves as a natural solder, so that neighbouring surfaces, when perfectly free from greasy matter, may be permanently joined together by moisture, heat and pressure, the union becomes perfect, but horn being a cheap material the process of joining it is seldom practised.
Our own supply of the horns of the ox and cow is insufficient for the numerous uses to which this substance is applied, and they are largely imported from Buenos Ayres and the Cape of Good Hope, also those of the bison and buffalo from the East Indies; the latter are sometimes very beautiful, and reserved for superior purposes. The straight conical horn of the rhinoceros is also occasionally used; it is solid, and formed as of a group of hairs cemented together; the transverse section of the upper part of the horn exhibits small dots. The horns of the chamois and antelope, and those of some other animals, are generally looked upon as natural curiosities, and are only polished exteriorly, without any strictly manufacturing process being applied to them.
The first step in operating upon horn is the separation of the bony core, which is effected by macerating the horns in water for about a month, when, from the putrefaction of the intermediate membrane, the core may be readily detached; this is not thrown away, but burnt to constitute the bone earth used for the cupels for assaying gold and silver.
The solid portion or tip of the horn is usually sawn off, and the remainder, if not cut into short lengths, is softened by immersion for half an hour in boiling water; it is then held in the flame of a coal or wood fire, until it acquires nearly the heat of melted lead, when it becomes exceedingly soft, after which it is slit up the side with a strong pointed knife, and opened out by means of two pairs of pincers applied to the edges of the slit; and lastly, the"flats" are inserted between iron plates previously heated and greased, which are squeezed tight in a kind of horizontal frame or press by means of wedges; wooden boards may be used.
For general purposes, as for combs, the pressure should be moderate, otherwise, in the language of the workman, it breaks the grain, or divides the laminae, and causes the points of the teeth to split; but great pressure is purposely used in the manufacture of the leaves for lanterns, which arc afterwards completely separated with a round-pointed knife, scraped and polished.* The heat and pressure when applied to the light coloured horn render it also transparent.
An improved mode of "opening horn" was invented by Mr. J. James, by which the risk of its being scorched or frizzled over the open fire is entirely removed; he employs a solid block of iron with a conical hole, and an iron conical plug: these are heated over a stove to the temperature of melted lead, and the horn, after having been divided lengthways with a saw or knife, is inserted in the hole, the plug is gradually driven in with a mallet, and in the space of about a minute the horn is softened and ready for being opened in the usual manner, +
In making drinking-horns, and some few other turned works, the material is cut to the appropriate length, brought to the circular form, and allowed to cool in the mould; the process is similar to that just described, although the old methods of the open fire and wooden cones are commonly used. The horn is then fixed in the lathe by its larger end, and turned on its innerr and outer surfaces, and the groove, or chime, for the bottom, is cut with an appropriate tool. A thin plate, previously cut out of a flat piece of horn with a crown saw, is dropped into the horn, and forced into the groove, after the horn has been sufficiently heated before the lire to allow the necessary expansion; in cooling the contraction fixes the bottom water-tight.‡