CLASS XXVIII.-MANUFACTURES FROM VEGETABLE AND ANIMAL SUBSTANCES.

POSITION OF CLASS.-Numbers referring to Pillars, North Gallery, between F. G. 26 and 32, the Porcelain Group, Class 25, being to the East of it and the Cutlery, Class 21, to the West.

The whole group is so small that it requires no subdivision.

Caoutchouc Manufactures. (Exhibitors 72, 73, 76, 77, 78, 81, 82, 83.)— The variety of forms under which India-rubber is exhibited sufficiently testify to the value of this curious substance, as an article adapted for manufactures. Caoutchouc is the milky and

H

WEST.

27 28 29 30

India Rubber, Gutta Percha.

SOUTH.

32

NOTRH.

China.

EAST.

C

Pottery.

33 34

resinous sap found in many plants, but especially derived from species of Siphonia, a genus belonging to the Spurge family; of Urceola and Vahea, genera of the dogbane family, and certain trees of the fig kind, especially Ficus elastica. The best caoutchouc is that procured from a Siphonia, a tree indigenous in Central America. The Urceola elastica is a creeping shrub, a native of the Indian Islands; and the Ficus elastica, a tree of the mainland of India and the neighbouring countries to the eastward. The South American kind was that first known in Europe; but its origin and uses were not understood until the early part of the last century. The bottles of India-rubber had been previously regarded merely as curiosities. They are made by spreading the milky juice, as it flows from the wounded tree, on moulds of clay, sometimes fantastically shaped. There are some curious examples in the Exhibition. These are dried over a smoky fire, and repainted

with fresh layers of juice, which are successively dried until sufficient thickness be attained. The large solid flat masses are prepared in a different manner. The product so procured attains different degrees of solidity. It is applied to manufactures in various ways. It may be dissolved in some menstruum, such as naphtha, or spirits of turpentine, (in which state it is called varnish,) or with a small quantity of solvent in the state of dough, it is spread upon cloth, from which it may be stripped, and forms sheets 50 inches wide and 100 feet long; or sheets may be made by kneading the rubber in powerful machinery, and, whilst hot, forcing it into oblong blocks, from which veneers or sheets may be cut. But the greatest improvement in its treatment and manufacture was the discovery of vulcanizing, a term applied to a peculiar amalgamation with sulphur by means of heat, when it obtains new properties, and retains any form that may be given to it by pressure during the process of vulcanizing, a discovery made by Mr. Thomas Hancock in 1843. sheet of caoutchouc immersed in melted sulphur absorbs a portion of it, and if continued at a higher temperature it undergoes some important changes in many of its characteristic properties. It is no longer affected by climatic temperature; it is neither hardened by cold, nor softened by any heat which would not destroy it. It ceases to be soluble in the solvents of common caoutchouc, while its elasticity becomes greatly augmented and permanent. The same effect may be produced by kneading sulphur into caoutchouc by means of powerful rollers, and then subjecting the compound to similar degrees of heat.”—Brockedon. The collections exhibited display the material in its raw state, and variously combined with cloths, and vulcanized. Among the more curious applications of it may be noticed the purchases for the raising and sustaining weights, and obtaining pressure. The elastic bow-strings (72), Indiarubber portable boats (81), and shower-baths (83), show some of the numerous uses to which it has been turned by

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Mackintosh and Co. (76). The series of specimens of South American caoutchouc (78) are well worthy of study. This substance was not imported into Britain to any considerable extent until within the last twenty years. According to the exhibitor of the Liverpool imports, 500 tons of it were brought from Maranham to Liverpool in 1850, being nearly five times the amount imported during the preceding year.

Various manufactures of elastic cloths, &c., are exhibited, into most of which caoutchouc enters.

Gutta Percha Manufactures. (Exhibitors 85, 86, 87, 90.) -A very few years ago this substance, now so useful, was either unknown or.regarded as a mere curiosity, and the tree from which it was derived had not been discovered. We now know that it is a kind of caoutchouc, the inspissated milky juice of the Isonandra gutta-found between the bark and the wood-a tree of slow growth, belonging to the natural order Sapotacea, and indigenous in the Indian Archipelago. This substance becomes soft in boiling water, and may be moulded into any shape, and converted into most useful vessels, tubes, and instruments, that are not intended to be used at a temperature above 50°. It is manipulated when soft with great facility, and can be pressed in moulds into any required shape. Combined with colouring matter, it may be converted into imitations of various substances, and even metals. Besides numerous ornamental applications, others of a more useful character may be noticed-such as carboys for holding acid, washbasins, ear-trumpets, whips, stethoscopes, tubes for inverting the wires of electric telegraphs, hats, dolls, and even into shoes for horses and constables' staves.

Vegetable Ivory. (Exhibitors 28, 47.)-The curious and beautiful substance out of which the ornaments here exhibited are carved, is the seed of a species of palm, the Phytelephas, a member of the screw-palm tribe. It is commonly called, in Peru, the Taqua, and also Negro's head. The value of the substance of the seed for trinket-making

has been long known to the natives of the region through which the river Magdalena flows, where these trees are abundant. It is only within a comparatively short time that it has been employed for turning in Europe. The hard white interior of the seed is the albumen stored up for the use of the embryo plant. At first this is a transparent fluid, but eventually, after becoming milky and opaque, it becomes solidified. When the seed germinates, the hard albumen becomes gradually changed as it is absorbed by the embryo plant. Handles for walking-sticks and umbrellas, buttons, &c., are made out of it, as well as very beautiful toys.

Manufactures of Cocoa-nut Fibre. (Exhibitors 39, 40, 43.) Coir, or fibre of the husk of the cocoa-nut, is a substance highly valuable for manufacturing processes. The husk is the main body of the fruit, the part we eat being properly a portion of the seed, its albumen, similar to the substance used for carving in the vegetable-ivory nut, also the seed of a palm. The husk is pulled to pieces and the fibrous portion completely separated from the rest of its substance in order to make coir. It is then one of the strongest vegetable substances known, and is largely used in the East for the manufacture of ropes and cables, and even of a coarse sail-cloth. Here we have it converted into mats, coarse and fine, and even into ladies' bonnets. In an uncombined state it is used for the stuffing of mattresses, and converted into a sort of vegetable hair. One case (40) shows all the stages of conversion of the cocoa-nut husk into coir. Manufactures are shown (39) made from a mixture of coir and Manilla hemp. The latter substance is the fibre of Musa textilis, a species of plantain, and not to be confounded with our hemp Cannabis sativa, a plant of a very different tribe.

Brushes (Exhibitors 3, 21, 29, 34, 52, 55A, 58, 61, 67, 68, 161, 181) are displayed in great number and variety. Not a few are exhibited on account of peculiarities in the mode of fixing the bristles. Among them are some (58) described

as cheap and durable, remarkable for being constructed of quills split into bristles, and others in which the material used for the same purpose is cocoa-nut fibre.

The various articles for the toilet are here exhibited (Exhibitors 81, 55, 84, 177), and are remarkable for neatness of workmanship. Here too are wigs and various arrangements of hair (Exhibitors 22, 62, 64), and combs made out of different materials (Exhibitors 18, 65, 152), but especially of tortoiseshell. This substance is the outer plating of the carapace of Testudo imbricata, a species of sea-turtle. It is separated from the bony portion by heating, and softened and moulded into various shapes by immersion in boiling water. The largest animals furnish the best shell.

Tortoiseshell is shown, also, inlaid with mother-of-pearl in boxes and similar articles. (Exhibitors 131, 132.) The effect arising from contrast of colour and texture is very pleasing. In these inlaid works, the mother-of-pearl varies in colour, some portions being of a rich lustrous green and · purple, others more pale and pearly. The former are used for framing the latter, and are derived from the shells of Haliotis, or ear-shell, of New Zealand; the latter are mostly obtained from the shells of Aviculæ or pearloysters.

Cork (Exhibitors 124, 125, 126) is the outer layers of bark of the Quercus suber, a species of oak indigenous in the South of Europe. The tree is usually not ready for stripping until twenty-five years of age or more, after which time it may be barked once every eight or ten years. The sheets of cork are scorched on both sides and pressed when hot between flat planks, in order to make the texture compact. The quality varies very much, according to soil or age of the tree, or interval between the operations of barking. It is a curious fact, that the use of cork for bottle-stoppers, now so universal, is a practice that originated long after this material was well known and variously applied, and that the ancients do not seem to have adopted