Plumbaginaceæ tary or disposed in fascicles in the axils of the leaves. The common garden plum (P. domestica), introduced from Asia Minor, is the most extensively cultivated, and its fruit is one of the most familiar of the stone-fruits. The varieties are very numerous, differing in size, form, color, and taste. Some are mostly eaten fresh, some are dried and sold as prunes, others again are preserved in sugar, alcohol, sirup, or vinegar. They make also excellent jams and jellies, and the sirup from stewed plums forms a refreshing drink for invalids, and a mild aperient for children. Perhaps the most esteemed Plurality call it. Near a range of high mountains the plumb-line, as can be shown by special arrangements, is not perfectly true, but inclines towards the mountains; and officers in charge of the United States Coast and Geodetic Survey among the Hawaiian Islands, have recently observed that the deviation of a plumb-line from the vertical is greater in the case of mountains in an island than in that of continental mountains, and greater in the neighborhood of extinct volcanoes than in that of active volcanoes. In given localities the plumb-line also varies according to the ebb and flow of the tide. of all varieties is the green gage. (See Plumptre (plump'ter), EDWARD HAYES, Dean of Wells, Green Gage.) A very popular and easily grown_sort is the P. damascena or dam- born in 1821. He was graduated from son. The wood of the plum-tree is hard, Oxford, appointed chaplain at King's compact, traversed with reddish veins, College, London, and was made professor susceptible of a fine polish, and is fre- of pastoral theology in 1853. He held quently employed by turners and cabinet- various pastoral positions, and as an able makers. The sloe or black-thorn (P. theologian and preacher was chosen a spinosa) is a species of wild plum bear- member of the Old and New Testament ing a small, round, blue-black, and ex- Revision Companies in England, select tremely sour fruit. Its juice is made preacher at Oxford (several times), Boyle into prune-wine, which is chiefly employed lecturer, 1866-67, and Grinfield lecturer, by distillers, wine and spirit merchants, 1872-74. He wrote a number of valuable etc., for fining, coloring, purifying, and works on theology, and we have from his mellowing spirits. pen several translations, including Soph(1887). He died in 1891. se-e), PLUMBA ocles (1866), Eschylus (1870), Dante Plumbaginaceae (plum-ba-jin-aGIN'EE, a nat. order of exogens, con- Plumule (plö'mül), in botany, that sisting of (chiefly maritime) herbs, somepart of the seed which grows what shrubby below, with alternate into the stem and axis of the future leaves, and regular pentamerous, often plant. In the seeds of the bean, horseblue or pink flowers. As garden plants chestnut, etc., the plumule nearly the whole of the order is much is distinctly visible, but in prized for beauty, particularly the Stat- plants generally it is scarceices. The common thrift or sea-pink ly perceptible without the (Armeria maritima), with grass-like aid of a magnifying glass, leaves and heads of bright pink flowers, and in many it does not apis a familiar example. The type of this pear until the seed begins order is the genus Plumbago. It consists to germinate. The first inof perennial herbs or undershrubs, with dication of development is pretty blue, white, or rose-colored flowers the appearance of the plumule, which is a in spikes at the ends of the branches. collection of feathery fibers bursting from P. Europaa is employed by beggars to the enveloping capsule of the germ, and raise ulcers upon their bodies to excite which proceeds immediately to extend itpity. Its root contains a peculiar crys- self vertically upwards. tallizable substance which gives to the skin a lead-gray color, whence the plant has been called leadwort. ite. Plumbago (plum-bā'go). See GraphPlummet (plum'et), PLUMB-LINE, a leaden or other weight let down at the end of a cord to regulate any work in a line perpendicular to the horizon, or to sound the depth of anything. Masons, carpenters, etc., use a plumb-line fastened on a narrow board or plate of brass or iron to judge whether walls or other objects are perfectly perpendicular, or plumb, as the artificers P, Plumule. Plurality (plö-ral'i-ti), in ecclesias tical law, signifies the holding by the same person of two or more benefices. Pluralities were forbid den by the canon law, but the bishops and the pope assumed the right of granting dispensations to hold them. They were prohibited by the Councils of Chalcedon (451), Nicæa (787), and Lateran (1215). In England pluralities in the church are forbidden excepting in particular cases, as, for instance, where two livings are within three miles of each other, and the value and population of each being small. Plus Plus (L, more), in mathematics, signifies addition; the sign by which it is indicated is +; thus A+ B, which is read A plus B, denotes that the quantity A is to be added to the quantity B. Plus, or its sign +, is also used to indicate a positive magnitude or relation, in opposition to minus which indicates a negative. Plush, a fabric similar to velvet, from Plymouth different writers and periods, and in later ages he was confounded with Plutus. The worship of Pluto was extensively spread among the Greeks and Romans. The cypress, the box, the narcissus, and the plant adiantum (maiden-hair) were sacred to him; oxen and goats were sacrificed to him in the shades of night, and his priests were crowned with cypress. He is represented in gloomy majesty, his forehead shaded by his hair, and with a thick beard. In his hand he holds a twoforked scepter, a staff, or a key; by his side is Cerberus. He is often accompanied by his wife. which it differs only in the length and density of the nap. The nap may be formed either in the warp or woof, the one in which it is being double, there being a warp and a woof for the body of the cloth, and a warp or a woof Plutonic Rocks (plö- tonik), unfor the nap. Plushes are now made stratified crystal almost exclusively of silk. The cheaper line rocks, such as granites, greenstones, qualities have a cotton backing. Some and others, of igneous origin, formed at of the finest dress plushes are produced great depths from the surface of the in London, plushes for gentlemen's hats earth. They are distinguished from those come chiefly from Lyons, while common called volcanic rocks, although they are or imitation plushes are largely manufac- both igneous; plutonic rocks having been tured in Germany. Plush is now also elaborated in the deep recesses of the extensively used in upholstery and dec- earth, while the volcanic are solidified at orative work. or near the surface. Plutarch (plö'tårk; Greek, PLOUTARCHOS), a learned Greek writer, born at Cheronæa in Boeotia, where he also died. Neither the year of his birth nor that of his death is accurately known, but it is generally held that he lived from the reign of Nero to that of Adrian (54-117 A.D.). He appears from his writings to have visited Italy, lectured there on philosophy, and stayed some time at Rome, where he established a school during the reign of Domitian. His Parallel Lives of Illustrious Greeks and Romans is the work to which he owes his fame. The lives are nearly all written in pairs, one Greek and one Roman, followed by a comparison of the two, and are models of biographical portraiture. We have numerous editions and translations of them. Plutarch's other works, about sixty in number, are generally classed as Moralia, though some of them are narrative. His writings show that he was well acquainted with the literature of his time, and with history, and that he must have had access to many books. Pluto (ploto), in classical mythology, the god of the infernal regions, the ruler of the dead. He was a son of Cronus and Rhea, a brother of Zeus (Jupiter) and Poseidon (Neptune), and to him, on the partition of the world, fell the kingdom of the shades. He married Persephōnē (which see). By the Greeks he was generally called Hades and by the Romans Orcus, Tartarus, and Dis Pater. As is the case with all other pagan deities, the accounts of Pluto vary with Plutus (plö'tus), in Greek mythology, the god of riches. Zeus struck him blind because he confined his gifts to the good; and he thenceforth conferred them equally on the good and the bad. His residence was under the earth. Plutus is the subject of Aristophanes's comedy of the same name. Pluviose (plö'vi-os), the fifth month of the French Republican calendar, extending from January 20 to February 18 or 19. See Calendar. Plymouth (plim'uth), a seaport of England, in Devonshire, at the head of Plymouth Sound, between the estuaries of the Plym and Tamar. Taken in its largest sense, it comprehends what are called the Three Towns,' or Devonport on the west, Stonehouse in the center, and Plymouth proper on the east. Plymouth proper covers an area of about 1 square mile, the site being uneven and somewhat rugged, consisting of a central hollow and two considerable eminences, one on the north, forming the suburbs, and the other, called the Hoe, on the south, laid out as a promenade and recreation ground. The old Eddystone Lighthouse has been re-erected in Hoe Park, which also contains a handsome statue of Sir Francis Drake by Boehm. The top of the Hoe offers magnificent land and sea views. The older parts of the town consist of narrow and irregular streets devoid of architectural beauty, but the newer parts and suburbs display an abundance of elegant buildings. The guild-hall, a Gothic building, is the finest modern edifice (1870–74), and has Plymouth Plymouth Brethren tower nearly 200 feet high; among canvas factories, also ironworks, cotton, other buildings are St. Andrew's Church, woolen, and silk mills, nail, tack, and wire the postoffice, the Royal Hotel, theater, factories, etc. Plymouth is the oldest and the athenæum. The citadel, an obso- town in New England, the place where lete fortification built by Charles II, is the Pilgrims landed from the Mayflower another object of interest. Plymouth is in 1620, Plymouth Rock' still marking well defended both land- and sea-wards by the place of landing. Pilgrim Hall, and a series of forts of exceptional strength a colossal monument to the pilgrims, on provided with heavy ordnance. Chari- the top of the adjoining hill, are the table and educational institutions abound: chief sights of the place. Pop. 12,141. the latter include a marine biological Plymouth, a town of Luzerne county, Pennsylvania, on the Susquehanna River, 4 miles below Wilkes-Barre. Coal-mining is extensively carried on, and there are hosiery mills, and manufactures of mining drills, miners' squibs, etc. Pop. 16,996. laboratory. The manufactures are not very extensive, and chiefly connected with ships' stores; but the fisheries are valuable, and Plymouth has a large export and coasting trade. Its chief importance lies in its position as a naval station. Thanks to extensive and sheltered harbors, Plymouth rose from a mere fishing village to the rank of foremost port of England under Elizabeth, and is now as a naval port second only to Portsmouth. To secure safe anchorage in the Sound a stupendous breakwater has been constructed at a cost of about £2,000,000. The Western Harbor, or the Hamoaze (mouth of the Tamar), is specially devoted to the royal navy, and here (in Devonport, which see) are the dock Plymouth a town (township) in Litchfield county, Connecticut. It has various manufactures, including lumber, hardware, etc. Pop. 5021. Plymouth Brethren, PLYMOUTHITES, a sect of Christians who first appeared at Plymouth, England, in 1830, but have since considerably extended over Great Britain, the United States, and among the Protestants of France, Switzerland, Italy, etc. They object to national churches as being too lax, and to dissenting churches as too sectarian, recognizing all as brethren who believe in Christ and the Holy Spirit as his Vicar. They acknowledge no form of church government nor any office of the ministry, all males being regarded by them as equally entitled to prophesy or preach. At first they were also called Darbyites, after Mr. Darby, originally a barrister, subsequently a clergyman of the Church of England, to whose efforts their origin and the diffusion of their principles are much to be ascribed. The Plymouth Brethren professedly model themselves upon the primitive church, yard, and Keyham steam-yard; the victualing yard, marine barracks, and naval hospital being in Stonehouse. The mercantile marine is accommodated in the Eastern Harbor, the Catwater (200 acres), or estuary of the Plym, and in Sutton Pool, and the Great Western Docks in Mill Bay. Plymouth is supplied with water from Dartmoor by a leat or channel constructed by Sir Francis Drake. Pop. (1911) 112,042. Plymouth, a seaport of Massachu setts, the seat of Plymouth county, 37 miles s. s. E. of Boston. It is situated in a capacious but shallow bay, and has extensive fisheries, rope and Plymouth Sound Pneumatic Tools and at an early stage of the movement are also widely used in the common there was a tendency towards the adop- household vacuum cleaner (which see). tion of the principle of community of See also Air-brake, Air-gun, etc. goods. They also, in general, hold mil- Pneumatic Dispatch a method of lennarian views, and Darby is exceedingly sending parminute in carrying out the allegorical in- cels through a comparatively narrow tube terpretation of the ceremonial and other by means of compressed air. In the United figurative parts of the Old Testament. States, where the circuit system is emThe interpretation of prophecy, as filling ployed, great progress has been made in up in detail the entire rôle of history, is the use of pneumatic power for posta feature of the views of Darby and the office work. B. C. Batcheller invented an Plymouthists. They baptize adults and improved system which has found very administer the sacrament, which each extended use. It consists of double tubes takes for himself, each Sunday. At their (of cast iron made in 12-ft. lengths) runmeetings a pause of unbroken silence en- ning parallel to each other. At the censues when no one is moved to speak. They tral station a steam-engine compresses the hold both civil governments and ecclesi- air and forces it into one of the tubes, astical organizations to be under divine along which it rushes, returning by the reprobation, the former as atheistic, the other, a constant current being kept up. latter as in a state of apostasy. Theolog- The tubes are worked at a pressure of ical differences early caused a split among six pounds per square inch, and for a the Plymouthists, and even during the distance of 4500 feet require about 30 lifetime of Darby there were three distinct horsepower, the transit speed being about divisions. 30 miles per hour. The system was first tried in Philadelphia in 1893, the tubes used being six inches in diameter. Eightinch tubes are most common. Plymouth Sound, an arm of the sea, on the southwest coast of England, between the counties of Devon and Cornwall. It is about 3 miles wide at its entrance, bounded by elevated land, which descends abruptly to the sea. It contains Drake Island, which is fortified, and the celebrated Plymouth Breakwater. See Plymouth. In the European system, as distinct from the American, the carriers being propelled from the central office by pressure and drawn_in_the_opposite direction by a vacuum. In London, Paris, Berlin, and Vienna it is employed for the delivery ik), are of these main tubes, 24 in. in diameter, averaging nearly one mile in length, radiate from the central station. Different offices in the same building are also commonly connected by a number of short tubes, the whole system being supplied with power from one main station. Pneumatic Appliances (nu'mat- of post-office telegrams. In London fifty of wide variety, ranging from simple airfilled cushions to engines. Compressed air was first used as a motive power by Dennis Papin in England about 1700. It was first used successfully on a large scale in 1861 in connection_with_ the construction of the Mont Cenis Tunnel. In 1867, A. E. Beach, an American, constructed a working model of an atmospheric railroad, but all attempts at pneumatic street traction in America failed. In 1886 J. G. Pohle, of Arizona, applied compressed air to the lifting of water, a method frequently used in connection with Artesian wells. for bridges are often sunk to the required The foundation for docks and the piers Pneumatic Gun, a gun which de rives its power from compressed air. It is fired by pulling a lanyard, which releases the air. Pneumatics, branch of physics which a former name for that treats of the properties of gases. See Air, Air-pump, Atmosphere, Barometer, Gas, Pump, etc. a class of port Pneumatic Tools, able mechanical depth by means of cylinders from which water is excluded by compressed air; and appliances operated by compressed air. the same method is used in tunneling. Air The motor is self-contained, and they are is also used in pumping water for supply generally worked by the hand. They are or drainage; in regulating temperature in of two types-percussion and rotary. In steam-heated buildings, and in a wide the former the work is accomplished by variety of apparatus in which a simple rapidly repeated blows, and in the latter mechanical push or pull is required. For by a boring action. They are used for a use as a motive power in locomotives and great variety of mechanical operations automobiles air is stored at high pressure permitting the actions of percussion and in a steel reservoir carried on the car, rotation, such as drilling, ramming, hamand is thence admitted into the driving mering, riveting, caulking, boring, screwcylinder. The force of suction obtained ing, expanding boiler tubes, and carving. by exhausting the air in a confined space A good representative of the percussion is used in grain elevators. Suction pumps tools is the pneumatic hammer. It con Pneumonia Po sists of a cylinder in which a piston inflammation of the smaller bronchi, works with a reciprocating (back and which spreads in places to the alveoli and forth) action, actuated by compressed air produces consolidation. All forms of admitted to and exhausted from the cyl- broncho-pneumonia depend on the invainder by suitably arranged openings. A sion of the lung by micro-organisms. No loose-fitting tool (such as a rivet-set, in one organism has, however, been concase the appliance is employed as a riv- stantly found which can be said to be eter) is inserted in the front end of the specific, as in lobar pneumonia; the influcylinder to which the compressed air is enza bacillus, micrococcus catarrhalis, conveyed by flexible hose connections, and pneumoccoccus, Friedlander's bacillus and through the handle at the rear. To oper- various staphylococci having been found. ate the device is held by the handle and The symptoms characterizing the onset the tool is pressed firmly against the of catarrhal pneumonia in its more acute work. The operator then admits the air- form are the occurrence during an attack pressure into the cylinder by pressing on of bronchitis or the convalescence from the throttle lever, and starts the recipro- measles or whooping cough, of a sudden cating hammer, which strikes the tool or and marked elevation of temperature, torivet-set at each forward stroke. The gether with a quickened pulse and inaction is similar to that of driving a chisel creased difficulty in breathing. The cough with a mallet or hammer, with the ex- becomes short and painful, and there is ception that the successive strokes are de- little or no expectoration. The physical livered with great rapidity, at a rate of signs are not distinct, being mixed up speed as high as 20,000 blows per minute, with those of the antecedent bronchitis; the efficiency of the appliance being due to but, should the pneumonia be extensive the frequency of the strokes rather than there may be an impaired percussion note to the power of each individual stroke. with tubular breathing and some bronPneumatic percussion tools, in general, chopany. Dyspnoea may be present in a are made small enough to be operated by marked degree; and death frequently ochand, and they are adapted for various curs from paralysis of the heart. uses by simply replacing the tool piece at the front end of the cylinder by tools specially shaped to fit the particular kind of work. a Pneumonia (nu-mō'ni-a), name given to various diseases associated with consolidation of portions of the lung tissue. Formerly the disease was divided into three varieties: (1) Acute croupous or lobar pneumonia; (2) Catarrhal or broncho-pneumonia ; (3) Interstitial or chronic pneumonia. sis of the lung) is a fibroid change in the Chronic interstitial pneumonia (cirrholung, chiefly affecting the fibrous stroma and may be either local or diffuse. The changes produced in the lung by this disease are marked chiefly by the growth of nucleated fibroid tissue around the walls of the bronchi and vessels, and in the intervesicular septa, which proceeds to such an extent as to invade and obliterate the air cells. The symptoms are very similar to those of chronic phthisis (see Tuberculosis). The malady is usually of long duration, many cases remaining for years in going temporary improvement in mild a stationary condition and even underweather, but the tendency is on the whole Acute croupous or lobar pneumonia (pneumonia fever) is now classed as an acute infective disease of the lung, characterized by fever and toxemia, running a definite course and being the direct result of a specific micro-organism or micro- downward. organisms. The symptoms are town of Cambodia, at generally well Pnom-penh (p'num pen'), the chief marked from the beginning. The attack is usually ushered in by a rigor (or in the apex of the delta of the Mekong. Pop. children a convulsion), and the speedy about 60,000. development of the febrile condition, the Po (po; anciently Padus or Eridanus), temperature rising to a considerable de- the largest river of Italy. It rises on gree-101 to 104 or more. The pulse is the confines of France and Piedmont in quickened, and there is a marked disturb- Mount Viso, one of the Cottian Alps, and ance in the respiration, which is rapid, receives during its long course to the Adri shallow and difficult, the rate being atic (about 450 miles) a large number of usually accelerated to some two or three tributary streams. It divides the great times its normal amount. The lips are plain of Lombardy into two nearly equal livid, and the face has a dusky flush. Pain parts, and is the grand receptacle for the in the side is felt, especially should any streams flowing south from the Alps, and amount of pleurisy be present, as is often for the lesser waters that flow north the case. The term broncho-pneumonia' from a part of the Apennine range. Its is used to denote a widespread catarrhal principal affluents are, on the left, the |