POLO. 211 POLTAVA. time accused of exaggeration in many particulars, subsequent travels have proved the accuracy of his observations. Little is known of Polo's his- tory after he left the Genoese prison, beyond the fact that a wife and three daughters survived him. Consult: San-Filippo, Htuili bingrafici e bihlioyrafici, vol. i. (Rome. 1882), which eon- tains a list of the various editions; the best one is that of Yule. The Book of Sir Marco Polo (2d ed., London, 1875). POLOCK, pol'otsk. An ancient city of Rus- sia. See Polotsk. POLO DE MEDINA, pQld da ma-oe'na, Sal- vador Jacinto (c.ltiO7-c.l660). A Spanish poet, born in Alurcia. He took orders when about thirtj' years old, and became secretary to the Bishop of Lugo. He wrote much satirical verse in his youth in the manner of Cervantes and Quevedo. His Academias del jardin ; Buen humor de las musas Apolo y Dafne, mostly poems; and Pan y Hiringa. a romance, were all printed in 1630. His Hospital de incurables, viaje de este mundo al otro ( 1636) . an imitation of Quevedo's (Sueiios, is in prose. He also wrote the elegant treatise Gobierno moral a Lelio (16.57), which had con- siderable influence on the literature of his cen- tury. His Obras en prosa y versa were first pub- lished in 1664. His verse is printed in Riva- denegra's Biblioteca de aulores espanoles, vol. xliii.' (.Madrid. 187.5). POLONAISE (Fr., Polish), or Polacca. A Polish national dance of slow movement, in | time. It always begins and terminates with a full bar, and a peculiar effect is produced by the position of its cadence, ,—^^i the dominant seventh in [—-9 — ~T Z^ w W — J J the second crotchet of the I H) *^ — - ^ ^ =q bar preceding the triad tJ ^ -^ ^ on the third crotchet: I I The characteristic rhythmic figure of the accom- paniment is rCrrrrr ■ ^t *l>e present day the polonaise is more a promenade than a dance, taking the place of the older entree. Grove claims that this dance was not orig- inally a popular dance, but originated at the coronation of Henry of Anjou at Cracow (1574). This statement seems to be confirmed by the fact that the oldest polonaises were not dance-songs, but purely instrumental pieces. Moreover, the entire character of the polonaise seems to indicate that it might well have had its origin in the need of some suitable music to accompany the movements of a solemn procession. Chopin gave to the polonaise a new aignificance as an instrumental form. The char- acteristic features of the polacca are .sometimes adopted in a rondo, or other lively and brilliant composition, which is then said to be written alia polaeca. POLONIUM (Neo-Lat., from Lat. Polonia, Pol. Polska, Poland). A metallic element dis- covered in 1898 by Madame Slodowski Curie. While studying the radio-aetivitwof various min- erals, Jladame Curie found that specimens of uraninite or pitchblende from certain localities showed more active radiation than metallic ura- nium, the principal metallic ingredient of ura- ninite. She thus became convinced that those minerals must contain some radio-active sub- stance hitherto unknown, and further examina- tion led her to the discovery of a new radio-active metal, resembling bismuth, for which she pro- pcsed the name polonium. At first the elemen- tary nature of polonium was questioned, and it was said to be a mixture of bismuth and some unknown substance. Markwald of Berlin, in his more recent researches, has endeavored to demon- strate that polonium is an element. The proper- ties of polonium are said to be similar to those of bismuth, although the metal resembles nickel in color. The suljnitrate of polonium has been pre- pared, and is a whitish powder. The special peculiarity of polonium is its wonderful radio- activity, which is said to be about three hundred times greater than that of uranium. JIarkwald has shown that polonium intercepts a strong cur- rent of eleetricitj' passing through the air from a generator to the receiver, the air ceasing to be a conductor for the flashes ; and that in the dark pieces of barium, platinum, and zinc sulphide, if placed near polonium, glow with a bright green- ish light. See Radio-Activity. POLO'NIUS. The chamberlain to the King of Denmark, and father of Ophelia and Laertes, in Shakespeare's Hamlet. Hidden behind the arras to overhear Hamlet and the Queen, he is killed by the former, who thinks it is the King. POLOTSK, po'lotsk, or Polock. An an- cient city of the Government of Vitebsk, Russia, situated on the Diina, 63 miles northwest of Vitebsk ( Map : Russia. C 3 ) . Its two ancient castles are now in ruins and a new church stands on the site of the Church of Saint Sophia orig- inally founded in the twelfth centurj-. There is a seminary for teachers. The chief manufactures are leather, pottery, tobacco, soap, and candles. Population, in 1897, 20,750, about 50 per cent. .Tewish. Polotsk was the capital of a medieval principality, which was absorbed by Lithuania. In the sixteenth century it was a prosperous and splendid city, but it was subsequently ruined by war and plague. It was taken by Russia in the first partition of Poland in 1772. It was the scene of severe conflicts between the Russians and the French during the Napoleonic invasion of Russia in 1812. POLTAVA, pol-tii'va, or PULTOWA, puK- ta-va. A government of Little Russia, bounded by the Government of Tcheniigov on the north, Kharkov on the east, Ekaterinoslav and Kher- son on the south, and Kiev on the west (Map: Russia, D 5). Area, about 19,090 square miles. The surface is undulating, slightly elevated in the north, and with a general incline toward the val- ley of the Dnieper in the southwest. It belongs to the basin of the Dnieper, by which river it is skirted on the southwest. The climate is moderate and steady, the annual temperature at Poltava, the capital, averaging about 46°. Poltava belongs to the black-soil region of European Russia and is one of the chief grain-producing districts of the Empire. Agiiculture is the principal occupation and is carried on on very primitive lines, modern machinery and fertilizers being confined principally to large estates. The leading products are rye, oats, and wheat. They are raised in quantities far above the domestic demand. The sunflower and flax.seed are culti- vated for the production of oil, and tobacco- raising is important. The vegetables of Poltava, especially the melons, are famous all over Rus- sia. Stock-raising, especially the breeding of
