RUBICON RUBINSTEIN 461 "Village Fete" in the Louvre. The British national gallery possesses the " Rape of the Sabines," which has been called "a perfect nosegay of color," the " Judgment of Paris," and several other works. Animal vigor, in the representation of which Rubens excelled, is seen nowhere with more effect than in his bacchanal feasts and mythological subjects of the coarser kind, of which " Castor and Pol- lux carrying off the Daughters of Leucippus," wonderful for its flesh coloring, and " Sleep- ing Wood Nymphs surprised by Satyrs," in the Pinakothek, are excellent examples. In his representations of the human figure he sel- dom attempted to idealize, and his Madonnas, Magdalens, and female saints are literally imi- tated from Flemish types of womanhood. As an animal painter he showed great excellence, and Sir Joshua Reynolds particularly com- mends his lions and horses, which, he ob- serves, " perhaps never were properly repre- sented but by him." His portraits are by some considered superior in their combinations of vigorous life with careful handling to any oth- er of his productions, especially his " Straw Hat," and his numerous portraits of himself and his wives ; while in his landscapes he ex- hibited, says Kugler, " the same juiciness and freshness, the same full luxuriant life, the same vigor and enthusiasm as in his historical pic- tures." Among the numerous biographers of Rubens are Waagen, in Raumer's Historisches TaschenbucTi (Leipsic, 1833 ; English transla- tion by R. R. Noel, edited by Mrs. Jameson, London, 1840); A. van Hasselt (1840); A. Michiels, Rubens et Vecole cPAnvers (Paris, 1854) ; Gustave Planche (1854) ; and Sainsbury (London, 1859). See also Waagen's " Trea- sures of Art in Great Britain " (4 vols., London, 1854-'7). His son ALBERT RUBENS (1614-'57) published several archaeological works. RUBICON, or Rnbieo, a small river of Italy, flowing into the Adriatic a little N. of Ri- mini (Ariminum), celebrated for its passage by Caesar in his march toward Rome, 49 B. C. This act was equivalent to a declaration of war against the republic, as the Rubicon was the dividing line between Italy and his province of Cisalpine Gaul. On reaching its brink he is said to have hesitated a moment and then plunged in, exclaiming : Jacta est alea (" The die is cast"). In 1756 a papal bull declared the Lusa, the larger and more southern of two neighboring streams, to be the Rubicon; but modern geographers generally prefer the Fiu- micino, formed by the Pisatello and Rugone. RUBIDIUM (Lat. rubidus, dark red), a metal of the alkalies, discovered by Bunsen and Kirchhoff in 1860 by means of the spectro- scope. The lines characteristic of the new metal are two remarkable bands of dark red lying beyond Fraunhofer's A, and consequent- ly in a part of the spectrum visible only by unusual methods. Two blue and some yel- low and green lines on the spectrum have since been observed. Rubidium occurs in a considerable variety of potash minerals, among which may be mentioned the deposits of the Stassfurt salt mines ; lepidolite from Rozna in Moravia, and from Goshen and Paris, Me. ; orthoclase, triphylline, carnallite, and saltpe- tre ; in mineral waters ; in beet root, tobacco, ashes of tea and coffee, crude tartar, ashes of oak and of a great variety of plants, be- ing very widely though sparingly distributed. The metal was extracted by Bunsen from the acid tartrate, 1,100 grains of which when distilled furnished about 80 grains of a bril- liant metallic mass. It is silver white, with a slightly yellow lustre, oxidizes rapidly in the air, and takes fire spontaneously. It is soft like wax at 14 F., melts at 101, and at red heat furnishes a blue vapor. It is more elec- tro-positive than potassium, and when thrown upon water takes fire and burns with a violet flame resembling that of potassium. It burns readily in chlorine, bromine, iodine, sulphur, and arsenic vapors. Its symbol is Rb ; spe- cific gravity, 1-52; atomic weight given by Bunsen at 85-36, by Piccard at 85-41. The salts of rubidium are with difficulty distin- guished from those of potassium, and the only certain test is the appearance of the flame in the spectroscope. The sparing solubility of the chloride of rubidium and platinum in boil- ing water is employed as one of the means of obtaining pure salts of rubidium. RUBINI, Giovanni Battista, an Italian singer, born at Romano, near Bergamo, in 1795, died there, March 2, 1854. In his boyhood his teach- er reported that he had no talent for singing ; but he persevered in his studies, and after an obscure career of several years in Lombardy made his debut at Brescia in 1815 with great success. He first appeared at Paris in 1825 as Ramiro in Rossini's Cenerentola, and speedily rose to the first place in his profession as a tenor singer. From 1831 to 1846 he sang prin- cipally in London, Paris, and St. Petersburg, and in the latter year retired with a large for- tune to a villa near Bergamo, where he passed the remainder of his life. His voice, a tenor of remarkable sweetness, extended from E to F above the staff, a compass of two octaves and one note, and has been known to reach as high as G above the staff. He excelled in the music of Bellini, and was almost unrivalled in the expression of sorrow and tenderness. He was an indifferent actor. RUBINSTEIN, Anton, a Russian musician, born in a frontier village of Bessarabia, Nov. 30, 1830. He is of Jewish descent, but was brought up by his father in the Greek faith. His mother was an excellent pianist, and instruct- ed him and his brother Nicholas, since direc- tor of the conservatory at Moscow, in the elements of music. The family removed to Moscow while he was still a child, and there at the age of six he began the systematic study of music. At the age of nine he gave his first public concert in that city. The re- sult was so encouraging that he was sent in