Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/517

RHU great repute as r.n astringent and corroborant; but, at present, it Is chieriy employed in perfuming po- jnatums J and forms an ingredient in rat-powders composed of poison- ous substances ; as these noxious vermin are uric-omrnonly partial to the agreeable scent of the diug. RHUBARB, or Rkcum, L. a genus of exotic plants, comprising bcven species, of which ihe follow- ing are the principal : 1. The rhaponticuni, or Com- mon Rhubarb, a native of Thr:ice and Syria, which has long been cultivated in British gardens fuv the footstalks of the leaves, that are frequently used in pies and tarts. The root of this species is some- times mistaken for the ofHcir.al rhubarb, from which it diliers ma- terially J as the surface of the for- mer is of a dusky colour, its tex- ture is more porous or spongy, and it possesses greater astringency than the latter, but is less purgative, re- quiring two or three drams, instead of tifteen or twenty grains of the powder, for one dose. 2. The pdniGtum, Palmaled, True or Officinal Rhubarb, is a native of China and the East In- ches, whence its culture has been introduced into Europe. It pro- daces a thick fleshy root, exter- nally yellowish-broun, but inter- nally of a bright-yellow ccih-ur, streaked with red veins j and it en- duns the severity of our climate. The oificinal rhubarb is rai.sed from seed, which should be sown /early in February, in 1 ght, san.iy soils, that have been previously ploughed to a considerable depth, and manured with a compost, con- sisting of one part of rotten dung, one part of sifted coal-aslies, and two parts of slaked lime, tho- rp;4ghly incorporated with a proper R H U [489 quantity of mud, or mire takea from a mill-pond. — This species is also propagated, by planting buds or eyes in land thus prepared ; which method is far superior to that before described ; as a whole year is not only gained in the growth, but the plant is less liable to be injured by the depredations; of vermin; and, in the course «f four or five years, the no/vns of the rhubarb will pro i nee tolerably good roots; which, however, are neither so large nor so plentiful as those obtained from seed. When the plants appear above ground, they wirl only require to be kept clear from all weeds; ard, if the roots be covered with litter, or tiie earth be drawn around tlsem, in the winter, they will vegetate with renewed vigour in the sj^ring. Should they grow too closely toge- ther, it will be necessary to thin thern, at the distance of five, or .six feet; and. at the expiration of four years, the roots may be take;i up for use ; though their medicinal properties are supposed to increa.se, if l!:ey be suffered to remain in the earth for seve'^., eight, ten, or even twelve years. The proper time for taking up the roots, in England, is from ihs middle of the summer to Jatiuary ; though they are sometimes dug out ot the ground early in the spring; or in autumn, when the leaves arc decayed. They are first washed clean, and the small fibres and ex- ternal rind being pa-f>d or cut ctf, they are divided into pieces about one ounce in weight. In warm weather, they should be dried 'ii the shade; but, if the .season be cold or wet, it will be advisable to evaporate their moisture graduol- hj in a hoi-house, or an oven of a moderate heat; because,, if drii!d too