agricultural implement works, match factories and ironworks. There is some export trade, especially in the Lipno district; but its development is hampered by lack of communications, the best being those offered by the Vistula. The railway from Warsaw to Danzig, via Ciechanow and Mlawa, serves the eastern part of the government.
After the second dismemberment of Poland in 1793, what is now the government of Plock became part of Prussia. It fell under Russian dominion after the treaty of Vienna (1815), and, in the division of that time into five provinces, extended over the western part of the present government of Lomza, which was created in 1864 from the Ostrolenka and Pultusk districts of Plock, together with parts of the province of Augustowo.
PLOCK, or Plotsk, a town of Russia, capital of the government of the same name, on the right bank of the Vistula, 67 m. by the Vistula W.N.W. of Warsaw, Pop. 27,073. It has a cathedral, dating from the 12th century, but restored in 1903, which contains tombs of Polish dukes and of Kings Ladislaus and Boleslav (of the 11th and 12th centuries). There is considerable navigation on the Vistula, grain, flour, wool and beetroot being exported, while coal, petroleum, salt and fish are imported.
PLOEN, a town of Germany, in Schleswig-Holstein, beautifully situated between two lakes, the large and the small Ploener-See, 20 m. S. from Kiel by the railway to Eutin and Lubeck. Pop. (1905), 3735. It has a palace built about 1630 and now converted into a cadet school, a gymnasium and a biological station. Tobacco, soap, soda, beer and furniture are manufactured, and there is a considerable trade in timber and grain. The lakes afford good fishing, and are navigated in summer by steamboats. Ploen is mentioned as early as the 11th century as a Wendish settlement, and a fortified place. It passed in 1559 to Duke John the Younger, founder of the line of Holstein-Sonderburg, on the extinction of which, in 1761, it fell to Denmark, and in 1867, with Schleswig-Holstein, to Prussia. The sons of the emperor William II. received their early education here.
See H. Eggers, Schloss und Stadt Ploen (Kiel, 1877), and J. C. Kinder, Urkundenbuch zur Chronik der Stadt Ploen (Plön, 1890).
PLOENNIES, LUISE VON (1803-1872), German poet, was born at Hanau on the 7th of November 1803, the daughter of the naturalist Philipp Achilles Leisler. In 1824 she married the physician August von Ploennies in Darmstadt. After his death in 1847 she resided for some years in Belgium, then at Jugenheim on the Bergstrasse, but finally at Darmstadt, where she died on the 22nd of January 1872. Between 1844 and 1870 she published several volumes of verse, being particularly happy in eclectic love songs, patriotic poems and descriptions of scenery. She also wrote two biblical dramas, Maria Magdalena (1870) and Dowd (1873).
As a translator from the English, Luise von Ploennies published two collections of poems, Britannia (1843) and Englische Lyriker des 19ten Jahrhunderts (1863, 3rd ed., 1867).
PLOËRMEL, a town of western France, capital of an arrondissement in the department of Morbihan, 36 m. N .N.E. of Vannes by rail. Pop. (1906), town, 2492; commune, 5424. The Renaissance church of St Armel (16th century) is remarkable for the delicate carving of the north façade and for fine stained glass. It also possesses statues of John II. and John III., dukes of Brittany, which were transferred to the church from their tomb in an ancient Carmelite monastery founded in 1273 and destroyed by the Protestants in 1592 and again at the Revolution. The lower ecclesiastical seminary has an apartment in which the Estates of Brittany held several meetings. Remains of ramparts of the 15th century and some houses of the 16th century are also of interest. Farm-implements are manufactured, slate quarries are worked in the neighbourhood, and there is trade in cattle, wool, hemp, cloth, &c. Ploërmel (Plou Armel, people of Armel) owes its name to Armel, a hermit who lived in the district in the 6th century.
PLOESCI (Ploescii), the capital of the department of Prahova, Rumania; at the southern entrance of a valley among the Carpathian foothills, through which flows the river Prahova; and at the junction of railways to Buzeu, Bucharest and Hermannstadt in Transylvania. Pop. (1900), 42,687. As the name Ploesci (pluviena, rainy) implies, the climate is moist. The surrounding hills are rich in petroleum, salt and lignite. There are cardboard factories, roperies, tanneries and oil mills. Ploesci possesses schools of commerce and of arts and crafts, several banks, and many synagogues and churches, including the Orthodox church of St Mary built in 1740 by Matthew Bassarab.
PLOMBIÈRES, a town of eastern France, in the department of Vosges, on a branch line of the Eastern railway, 17 m. S. of Epinal by road. Pop. (1906), 1882. The town is situated at a height of 1410 ft. in a picturesque valley watered by the Augronne. It is well known for its mineral springs, containing sodium sulphate and silicic acid, varying from 66° to 166° F. Plombières has a handsome modern church and a statue of the painter Louis Français, born in the town in 1814. The waters were utilized by the Romans and during the middle ages. In later times Montaigne, Richelieu, Stanislas, duke of Lorraine and Voltaire were among the distinguished people who visited the place. Napoleon III. built the most important of the bathing establishments and made other improvements.
PLOT, ROBERT (1640–1696), English naturalist and antiquary, was born at Borden in Kent in 1640. He was educated at Wye, and at Magdalen Hall, Oxford, where he graduated B.A. in 1661, and proceeded to M.A. (1664) and D.C.L. (1671). He was distinguished for his folio work The Natural History of Oxfordshire (1677), in which various fossils, as well as other objects of interest, were figured and described. It was regarded as a model for many subsequent works. In 1677 Plot was elected F.R.S., and he was secretary of the Royal Society from 1682 to 1684. He was appointed in 1683 the first keeper of the Ashmolean Museum at Oxford, and in the same year he became professor of chemistry. In 1686 he wrote the Natural History of of Staffordshire. Two years later he became historiographer-royal. He died on the 30th of April 1696.
PLOT, a term originally meaning a space of ground used for a specific purpose, especially as a building site, formerly in frequent usage in the sense of a plan, a surveyed space of ground; hence the literary sense of a plan or design. The word is of doubtful origin; there is a collateral form “plat,” which appears in the 16th century, according to the New English Dictionary, under the influence of “plat,” flat place, surface (Fr. plat, Late Lat. plattus, probably from Gr. πλατύς, broad). Skeat (Etym. Dict.) refers “plot,” in the sense of a space of ground, to the O. Eng. plaec, Mid. Eng. pleck, later platch, patch. “Plot,” in the sense of plan, scheme, would then be identical with “plot,” a conspiracy, which may be a shortened form of “complot,” a French word, also of doubtful origin, meaning in the 12th century “a compact body of men”; in the 14th century “conspiracy.”
PLOTINUS (A.D. 204–270), the most important representative of Neoplatonism, was born of Roman parents at Lycopolis in Egypt. At Alexandria he attended the lectures of Ammonius Saccas (q.v.), the founder of the system, until 242, when he joined the Persian expedition of Gordian III., with the object of studying Persian and Indian philosophy on the spot. After the assassination of Gordian in 244, Plotinus was obliged to take refuge in Antioch, whence he made his way to Rome and set up as a teacher there. He soon attracted a large number of pupils, the most distinguished of whom were Amelius, Eustochius and Porphyry. The emperor Gallienus and his wife Salonina were also his enthusiastic admirers, and favoured his idea of founding a Platonic Commonwealth (Platonopolis) in Campania (cf. Bishop Berkeley’s scheme for the Bermuda islands), but the opposition of Gallienus’s counsellors and the death of Plotinus prevented the plan from being carried out. Plotinus’s wide popularity was due partly to the lucidity of his teaching, but perhaps even more to his strong personality. Assent developed into veneration; he was considered to be divinely inspired, and generally credited with miraculous powers. In spite of ill-health, he continued to teach and write until his death, which took place on the estate of one of his friends near Minturnae in Campania.
