Volume 2
Cyclopædia of India and of eastern and southern Asia, commercial, industrial and scientific : products of the mineral, vegetable and animal kingdoms, useful arts and manufactures / edited by Edward Balfour.
- Date:
- 1857
Licence: Public Domain Mark
Credit: Cyclopædia of India and of eastern and southern Asia, commercial, industrial and scientific : products of the mineral, vegetable and animal kingdoms, useful arts and manufactures / edited by Edward Balfour. Source: Wellcome Collection.
42/872 page 1238
![MOT ILER-OF-PE A ILL. shells were shown, such as the Meleagrina mar- gari/ifera, llaliolis gigas, HaliotU iris, and a large species of Turbo, which shells arc known in commerce as Jlnt-skells, ear shells, green snail- shells, buffalo-shells, Bombay shells. Messrs. Fauu- tleroy and Mr. Banks had also some fine collec- tions. The latter gentleman states that the shores of the Sooloo Islands afford the finest shells. The beautiful tints of mother-of-pearl depend upon its structure ; the surface being covered with a multitude of minute grooves, which decompose the reflected light. Sir David 'Brewster, who was the first to explain these chromatic effects, discovered, on examining the surface of mother-of-pearl with a microscope, “ a grooved structure, like the delicate texture of the skin at the top of an infant’s linger, or like the section of the annual growths of wood as seen upon a dressed plank of fir. These may sometimes be seen by the naked eye ; but they are often so minute that .‘5,000 of them are con- tained in an inch.” It is remarkable that these iridescent hues can be communicated to other surface as a seal imparts its impress to wax. The colours may be best seen by taking an im- pression of the mother-of-pearl in black wax ; but “ a solution of gum arabie or of isinglass, when allowed to indurate upon a surface of raother-of pearl, takes a most perfect impression from it, and exhibits all the communicable colours I in the finest manner, when seen either by reflec- ! lion or transmission. By placing the isinglass between two finely-polished surfaces of good specimens of mother of-pearl, we ‘ obtain a film of artificial mother-of-pearl, which, when seen by single lights, such as that of a candle, or by an aperture in the window, will shine with the brightest hues.” [Brewster’s Optics, Chapter XIV., one of the volumes of the Cabinet Cyclo- paedia.] It is in consequence of this lam- mellar structure that pearD-shells admit of being split into laminae for the handles ol knives, for counters, and for inlaying. Splitting, however, is liable to spoil the shell, and is therefore avoided as much as possible. The dif- ferent parts of the shell are selected as nearly as possible to suit the required purposes, and the excess of thickness is got rid of at the grind- stone. In preparing the rough pearl-shell, the square and angular pieces are cut out with the ordinary brass-back saw, and the circular pieces, such as those for buttons, with the annular or crowu-saw, fixed upon a lathe-mandrel. The pieces are next ground fiat upon a wet grindstone, the edge of which is turned with a number ot grooves, the ridges of which arc less liable to be clogged than the entire surface, and hence grind more quickly. If the si one he wetted with soap and water it is less liable to be clogged. The pieces are finished on the fiat side of the stone, and are then ready for inlaying, engraving, polishing, Ssc. Cylindrical pieces are MOW C1IOK. cut out ol the thick part of the shell, near flic hinge, and are rounded on the grindstone prepa- ratory to being turned in the lathe. The finish- ing and polishing are described in the third vo- lume of Mr. lloltzapffel’s excellent work on Me- chanical .Manipulation.” Counters, silk-winders Ssc., are smoothed with Trent sand or pumice- stone and water on a bull-wheel or hand-polisher, and are finished with rotten stone moistened with sulphuric acid, which develops finely the striated structure of the shell. For inlaid works the surface is made flat by filing and scraping; then pumice-stone is used, and after this putty-powder, both on buff-sticks with water ; and the fine polish is given with rotten stone and sulphuric acid, unless tortoise-shell or some other substance liable to be injuriously affected by the acid be present in the mlay. In turned works fine emery- paper, rotten-stone and acid or oil arc used. The pearl handles for razors are slightly r voted together in pairs, then scraped, sauil buffed on the wheel with Trent sand and water; thirdly, gloss-buffed on the wheel with rotten stone and oil, or sometimes with dry chalk rubbed on the same wheel ; and fourthly, they are bunded up, or polished with dry rotten-stone and the naked hand.— Tomlinson. (5457) MOTHER-WATER, the liquor left after a saline solution has been evaporated so as | to deposit crystals oil cooling.—Faulkner. (5458) MOTIlllCS. Gijms and Gum Resins. Let-pan, Bua. Bombgx pentandru, and Bomb ax lielerophylla, are two common trees found in every part of the Pegu Forests which yield an astringent gum resin, called in the bazars of Bengal Mothrus. 1 have not been able to learn whether the Burmese ex- tract this gum, but from the abundance of trees affording it, it might become an article of some importance..—McClelland- (5459) MOTHS. At Lemu Samdong in the Lacben valley Nocluit and Geometric abounded, with many Hies and Tipuhe. Ilymenoplei'a were scarce, except a yellow Uphion, which lays its eggs in the caterpillars above-mentioned.— Hook- er, lTol. 11. p. 05. (5460) MOW CHOK. Bambusa, species. The most beautiful bamboo in the world— was growing about in wild profusion. This bamboo I have never met in any other part of the world. In the central and eastern provinces of China it is largely cultivated, particularly on the sides of mountains where the soil 'is rich, and in the vicinity of temples and other monastic buildings. Its stems arc straight, smooth, and clean, the joints arc- small, it ‘ grows to the height of from sixty to eighty feet. Twentv or thirty feet of the loner part of its stem are. generally free from branches. These are produced on the. upper portion of ^ flic tree, and theu they are so fight, and □ feathery](https://iiif.wellcomecollection.org/image/b28708921_0002_0042.jp2/full/800%2C/0/default.jpg)
