Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/531

ROO Ifee whole process is minutely de- w:nbed. — See also Air. ROOT, in botany, denotes that part of a plant, which imbibes the nutritious juices from the earth, and conveys them to the stem, leaves, blossoms, and fruit. Botanists have divided roots into thrpe classes, according to their shape or tigare, their situation in the ground, and tieir duration. I. "Witi- resp-j*.'-!; to mgure, roots are either nrnple ; spi/idle- shaped, as in the carrot; litten off, as in the devii's-bit scabious j lidbous (se^ Bulb, vol. i. p. 386) ; tuberous, as in the potatoc; lead- ed; IraiicJi-ed; hair-like; jointed; scaly ; pendant ; toothed ; fascuu- latcd, or hindled. II. The roots, which are denomi- nated from their situation, are either perpendicular; horizontal; oblique; creeping; zig-zag, or in- fiecied; or such as put forth suckers. III. With regard to their du- ration, roots are either c««ya/, that is, they flower and decay in one year ; biennial, when they con- tinue to vegetate two years ; and perennial Tools, are such as flourish for several, or at least more than two, years. These essential parts of plants greatly contribute to the comfort, and to the benefit of mankind ; as Biany of them not only atford whole- some and nutritious food, but are of considerable utility in medicine. Several roots also impart colours, "U'hich are employed both in arts and in m;unifadures; and are, in general, more durable than those obtained from the plants. Tims, the expressed juice of the comnjon radish, when combined with to- bac(.o-pipe clay and a little alum, yields a blue of considerable per- Rianency and brightness. R O O [SOS Notwithstanding their tinging properties, however, the generality of loots is etiolated, or perfedtly v/hite, in consequence of their se- clusion from tlie light. This phe- nomenon, in the opinion of Dr. Da R WIN, arises from the libera- tion or evolution of their superflu- ous oxygen, which unites with the colouring matter, and converts the latter into a coh^jrless acid ; excepting in such roots as contaia too large a proportion of the dye- ing substance, fur instance, in the miidder; the roots of which, ex- ternally, are red, while the inter- nal part is yellow. — See also Light. Root of Scarcity. SccMan- GEL-WURZKL. ROOT-STEAMER, an useful machine, employed in America, for steaming potatoes, carrots, and other roots, with the view of feed- ing cattle ; and which, for the sim- plicity of its contrivance, and the facility with > hich vegetables may thus be prepared, deserves to be more genendly known in Britain. We have therefore subjoined the following representation : The apparatus here delineated^ consists of a brick-stove, in which a pot or Ixttlc is fixed : over this Kk 4 boil«r