GITT1A-PERTHA (pronounced pertsha), a substance in many respects similar to caoutchouc, is the dried milky juice of a tree, iamundot gotta, which is found in the peninsula of Malacca and the Malayan archipelago. The tree belongs to the natural order sapotaceal It is a very large tree, the trunk being sometimes 3 ft. in diameter, although it is of little use as a timber tree, the wood being spongy. The leaves arc alternate, on long stalks, obovate-oblong, entire, somewhat leathery, green above, and of a golden color beneath. - The flowers are in little tufts in the axils of the leaves, small, each on a distinct stalk; the corolla having a short tube and 6 elliptical segments; they have 12 stamens and 1 pistil. The name gutta-percha is _Malayan, gutty signifying the Concrete juice of a plant, and perdue being the name of the particular tree from which it is obtained. The present mode of obtaining the gutta-percha is a most destruc tive one. The finest trees are selected and cut clown, and the bark stripped off; between the wood and bark, a milky juice is found; which is scraped up into little troughs made of plantain leaves. This is the gutta-percha, which, as it hardens, is kneaded into cakes, and exported.
Gutta-percha wasknown in Europe long before its peculiar character and uses were made known. It was from time to time brought home by voyagers, in the form of drinking-bowls, which excited much curiosity on account of the material of which they were made. Some thought it a species of india-rubber, others asserted it to be a kind of wood, which they named Maze r woo , from its use in making these drinking cups. But we are chiefly indebted to Dr. 'William Moutgonterie of the Indian, medical oervice, whose introduction of it in 1843 was rewarded by the gold medal of the society of arts. He first noticed that the Malays used it for making handles to their knives, etc.; and it immediately occurred to him that it might be of great use in a variety of ways, especially in making handles for surgical instruments. Since that tune, the importation of gutta-percha has increased amazingly; in 1860 it exceeded 16,0U0 cwts. Tile years 1864, 1865, 1870, and 1871 were marked by large imports, varying from 25 9 11 cwts, to 35,636 cwts.; in the years 1872 to 1870, the imports varied from 19,627 ewts. to 54,898 cwts. It has been used for making a vast variety of ornamental and useful articles; but its mist important application has been the coating of marine elec tric telegraph wires. In this application, as in most others, its inherent defect. arising from the readiness with which it becomes oxidized and decomposed, is unfortunately manifesting itself seriously, and a substitute having greater stability is anxiously looked for.
Its great value arises from the ease with which it can be worked, and its being so complete a non-conductor of electricity. It softens in warm water, and can be molded into any form iu that state; as when soft it is not sticky, and turns well out of molds. It will always be of great value as a material in which to take casts, as it can in the soft state be made to take the sharpest forms most faithfully, and as it quickly becomes hard, and preserves its shape if not too thin, the range of its utility in this respect is very extensive. Golf balls are made of gutta-percha.
It is imported in blocks and lumps of five to ten pounds weight, in various forms, chiefly like large cakes, or rounded into gourd-like lumps. It has a very light reddish brown, or almost a flesh color, is full of irregular pores elongated in the direction in which the mass has been kneaded. It has a cork-like appearance when cut. and a peculiar cheese-like odor. Before it can be used, it has to undergo some preparation. This consists in slicing the lumps into thin shavings, which are placed in a deviling or tearing machine revolving in a trough of hot water. This reduces the shavings to exceedingly small pieces, which, by the agitation of the tearing-teeth, are washed free from many impurities, especially fragments of the bark of the tree, which, if not sepa rated, would interfere with the compactness of its texture, which is one of its most important qualities. Time small fragments, when sufficiently cleansed. are kneaded into masses which are rolled several times between heated cylinders, which press out any air or water, and render the mass uniform in texture. It is then rolled between heated steel rollers into sheets of various thickness for use, or is formed into rods, pipes for water, or speaking tithes, and an endless number of other articles.
Gutta-percha differs very materially from caoutchonc or india-rubber in being non elastic, or elastic only in a very small degree. Notwithstanding this very striking character of cammtchoue, the articles are very often confounded in the public mind, probably from the similarity of applications: It is most probable that indium-rubber will eventually displace gutta-percha in some of Its most important applications, and especially in the coating of telegraph wires, to which purpose it has been successfully applied in America. There are two or three kinds of gutta-percha known in commerce, and it is more than probable these are yielded by different species: that from Singapore is esteemed the best, and is distinguished by the Malay traders as gutta taban or tubaa; that of Borneo is of less value—this is called gutta-percha by the traders, and has given the general name to all; and another kind goes by the name or gutty girek. The first two are those generally kuown in our markets.
Gutta-percha is turned by surgeons to various uses, chiefly for splints and covering moist applications to retard evaporation. A splint of gutta-percha is made by taking a rigid board of the substance cut to the desired shape, soaking it in hot water, and then bandaging it to the limb. In a few minutes the gutta-percha is found hard, and mod eled to the shape of the parts. The cloth of gutta-percha is sometimes used instead of oiled silk, as it is about half the price; it is, however, apt to tear, does not stand much heat, and is less flexible. Gutta-percha being readily soluble in chloroform, such a solution is sometimes used for covering raw surfaces, as when the chloroform evapo rates it leaves a pellicle of solid gutta-percha. It has also been used for stopping hollow teeth.