[Mr. Andrew Mathews, of Lima, has communicated to the _Gardeners' Magazine_ the following account of the Otaheitan method of preparing the excellent farinaceous substance termed _Arrow Root_, so extensively used in this country.] The root (_Tacca_ pinnatifida _Lin._, the _Pea_ of the natives) grows in the greatest abundance in all the islands which we visited; viz., in Otaheite, Eimeo, Huaheine, Raiatea, and Otaha. Its favourite situation is on the sides and ridges of the hills which rise directly from the sea, and which are generally covered with a coarse grass, on a red sandy loam. The root is round, white, smooth, full of eyes like a potato, and from 2 to 3 in. in diameter. The flower-stem rises directly from the root, simple; from 2 to 4 ft. in height, as thick as a man's finger, bearing its flowers in a loose simple umbel on the summit; and, when large and full blown, it presents a beautiful and delicate appearance. The leaf is large, tri-pinnatifid, segments acute, of a rich shining green: it is subject to great variation in the size of the segments, some leaves being much more cut, and having the segments narrower, than others. When a sufficient quantity of the roots is collected, they are taken to a running stream, or to the sea-beach, and washed; the outer skin is carefully scraped off at the same time with a shell; and those who are particular in the preparation scrape out even the eyes. The root is then reduced to a pulp, by rubbing it up and down a kind of rasp, made as follows:--A piece of board, about 3 in. wide, and 12 ft. long, is procured, upon which some coarse twine, made of the fibres of the cocoa nut husk, is tightly and regularly wound, and which affords an admirable substitute for a coarse rasp. The pulp, when prepared, is washed first with salt or sea water, through a sieve made of the fibrous web which protects the young frond of the cocoa-nut palm; and the starch, or arrow-root, being carried through with the water, is received in a wooden trough made like the small canoes used by the natives. The starch is allowed to settle for a few days; the water is then strained, or, more properly, poured off, and the sediment rewashed with fresh (or river) water. This washing is repeated three times with spring water; after which the deposit is made into balls of about 7 or 8 in. in diameter, and in this state dried in the sun for twelve or twenty-four hours. The balls are then broken, and the powder spread for some days in the sun to dry; after which it is carefully wrapped in _tapa_ (the native cloth), and put into baskets, and hung up in the houses. The natural indolence of the people is so great, and their avarice such, that but few of them will give the arrow-root sufficient time to dry, if they have an opportunity of parting with it, which I suspect was the case with that sent to England some few years back by the missionaries. So abundant is the root, that several tons might be prepared annually by