302 RHONE RHUBARB the Mediterranean sea by two mouths, after a circuitous but general W. and S. course of about 600 ra., 350 of which are in France. It originates at the foot of the Mayenwand, on the W. side of the St. Gothard, near the Furca pass, but can scarcely be called a river until its junction with several other streams at the bot- tom of the Rh6ne glacier, about 5,500 ft. above the sea. Thence it traverses Valais in a S. W. and then N. W. direction aa a mountain tor- rent, passing by Sion, till it enters the lake of Geneva near its E. extremity, where it has de- scended upward of 4,000 ft. In this part of its course it receives many small tributaries, the most important of which is the Dranse. When the Rhdne enters the lake of Geneva its waters are exceedingly turbid ; but on issuing from the S. W. extremity of that lake the river is of a clear blue color, which, however, is changed to brown by the accession of the Arve, a mud- dy stream, about 1-J m. below Geneva. It flows S. W. for about 15m. till it enters France, when it turns S. through a narrow pass between the Alps and the Jura. A little way below this place is the Perte du Rh6ne, where the river descends into a deep chasm partly covered over with massive fragments of rock. The Valse- rine, a fine stream from the Jura, joins here from the right. At St. Genix, where the Rh6ne receives the Guiers from the south, it turns abruptly N. W. and afterward more to the west, till it reaches Lyons, receiving du- ring this part of its course the Ain from the north ; and at Lyons it is joined by the Sa6ne, also from the north. The Rh6ne is here a considerable river, and flows almost due S. to Aries, through a beautiful and fertile country, but the rapidity of the current and the shifting sands in its bed render navigation dangerous and tedious. The most important tributaries in this part of its course, from the Cevennes on the right, are the Doux, Ardeche, Oeze, and Gard ; and on the left, from the Alps, the Isere, Drdme, and Durance. At Aries the river separates into two branches, the princi- pal one, called the Grand Rh6ne, flowing S. E. to the sea, while the other, called the Petit Rh&ne, flows S. W., enclosing between them the deltoid island of Camargae. The Grand Rh6ne enters the gulf of Lyons below the Tour St. Louis, and has there commenced the for- mation of a new delta ; and the Petit Rh6ne has its mouth a little W. of the village of Saintes Maries. Both these mouths are so much obstructed by bars, that vessels from the Mediterranean enter the river by the Etang de Berre, a shore lake or lagoon to the east, which is connected with the Rhone by the Martigues canal, and by the Beaucaire canal, which leads from Aries to the lagoons to the west on the coasts of the departments of Gard and Herault. Steamers sometimes ascend the Rh6ne as far as Seyssel, and by means of the Sa6ne it is navigated to Chalon; while by canals it is connected with the Garonne, Seine, Loire, and Rhine. The Rh6ne is of great commercial importance, and below Lyons is navigated by numerous steamers. The Paris and Marseilles railway runs along its left bank between Lyons and Aries; and in this part of its course the river passes many consid- erable towns, the principal of which are Vi- enne, Tournon, Valence, Avignon, Beaucaire, Tarascon, and Aries. Some of the finest wines of France are produced on the banks of the Rh6ne below Lyons. RHONE, a S. E. department of France, formed from the old province of Lyonnais, bordering on Sa6ne-et-Loire, Ain, Isere, and Loire ; area, 1,077 sq. m. ; pop. in 1872, 670,247. The de- partment is traversed in a N. and S. direc- tion by a continuation of the Cevennes ; Mont Tarare, the highest summit, is about 3,300 ft. above the sea. The Rh6ne and Sa6ne form the E. boundary. The soil is not fertile, and only about half the surface is arable ; the vine is grown, and some of the wines are excellent. It i> divided into the arrondissements of Lyons and Villefranche. Capital, Lyons. RHUBARB (Lat. rha, or rhcu barbarum, a name given by the early writers), in medicine, the root alone of rheum officinale and some other species, but in horticulture the name of the plants of several species. The genus rheum (either from Gr. 0i>, to flow, in reference to its purgative properties, or from Rha, the an- cient name of the Volga, upon the banks of which it grew) belongs to Asia and southern Russia ; and growing in localities from which Europeans have been excluded, there has been much confusion as to the species, of which ac- cording to Meisner there are about 20. They are all perennials, with large woody rootstocks, from which proceed radical leaves with long, thick petioles, the blade of the leaf usually very broad, entire, or variously lobed, and with strong palmate ribs ; the annual stem is erect, large, and hollow, bearing smaller leaves, and spikes or panicles of flowers; all the leaves have large sheathing stipules, but those of the stem leaves are very conspicuous ; the apeta- lous flowers have a white, greenish or pinkish, six-parted calyx; nine stamens; a triangular ovary, surmounted by three styles, and becom- ing a three-winged fruit. The common rhu- barb of the gardens, or pie plant, as it is fre- quently called, is a familiar representative of the genus ; this species, R. Rhaponticum (with several synonymes), a native of Siberia and tho country along the Volga, was introduced into England as early as 1573, and in the time of Elizabeth its leaves were in use as a pot herb, like spinach. It is now cultivated in gardens solely for its acid petioles or leaf stalks, which are used as a substitute for fruit, a custom un- known until early in the present century. Com- ing early in spring (and they may be had by forcing at any time during the winter), at a season when fruit is scarce, the leaf stalks are in great demand; their consumption in England is even more general than with us. The rapid- ly grown stalks contain but little woody fibre,
