continence, must be distiiifruislied from irritable
bladder, as it is in nearly every case the sigii of
a distended bladder. Retention of the urine may
be caused by mechanical obstacles to its exit, by
paralysis, or by an absence of volitional power
over the muscles. This last is termed hysterical
retention, and is common in young girls, in per-
sons suffering from seasickness, from nostalgia,
from operation or from accident, such as a
broken leg, etc. The power generally soon re-
turns. Any long-continued difficulty in passing
water is generally followed by a thickening of the
walls of the bladder itself, or hypertrophy. The
mucous membrane may form pouches in these
thickened walls — a condition which is called sac-
enlated bladder; cancerous diseases and tubercle
may also attack this organ.
The bladder is liable to be ruptured by acci- dent from without ; as. for instance, by a blow. As this accident is usually fatal, prompt surgical aid must be secured.
BLADDER CAMPION. See Silexe.
BLADDERNUT (for deiivation see below), tttaphylea. A genus of plants, the type of a small natural order, Staphyleaceae. Only about seven species are known, which are found in very different climates, and scattered over the world. They are mostly small trees of rather elegant appearance. The seeds contain a considerable quantity of a fixed oil, which is slightly purga- tive. The common bladdernut (fltaphylea pinna- ta) is a native of the east of Europe, and of tem- perate parts of Asia, which has been admitted into the British flora, but has in all probability been introduced as an ornamental tree. It is frequently planted in shrubberies, as is also Utaphylea trifolia, a North American species ^vitll ternate leaves. The wood of both is firm and white, well suited for the purposes of the turner. The seeds may be eaten, but act as a mild aperient. The flower-buds are pickled as capers. The name bladdernut has reference to the curious inflated membranous capsule, and the hard, bony "testa' of the seed. The name Sta- phylea is from the Gk. araov/.i), staphyle, a bunch of grapes, and has reference to the ra- cemed flowers. See Plate of BiGXOXiA, etc.
BLADDEKWORM. An encysted larval tape- worm. See Hyoatid and T.pewobm.
BLADDERWORT (so named from the vesi- cles by means of which the flowers float above the water), Utricutaria. A genus of plants of the natural order Lentibulariacea;, containing a large number of species, the bright blossoms of which, along with those of water-lilies, etc., adorn the surface of lakes, ditches, and marshes in almost all parts of the world. They are particularly abundant within the tropics, and many are natives of -ustralia. In the United States are found a dozen or more species with yellow, violet, or purple flowers. Great Hritain has only three species, all of which have -ellow flowers. These plants are very interesting from the provision made for the expansion of their flowers above water, although the whole jjlant is ordinarily submerged. The stems and leaves are furnished with numerous little bladders or vesicles, which are filled with water till it is necessary that the plant should rise for the ex- pansion of the flowers, when they become filled with air; and this, again, gives place to water after flowering is over, so that the seeds are ripened at the bottom. The bladders, at lea.st of Utricutaria rulgnris, have an orifice closed by a very thin ela.stie valve oi)ening inward. Aquatic insects sometimes enter them, are imprisoned, and the plant utilizes the products arising from their decay. See Plate of Bignonia, etc.
BLA'DENSBURG. A town in Prince George County, JId., (1 miles northeast of Washington (.Map: Maryland, K 5). Here, on August 24, 1S14, a British force of 5U00 men, under General Uoss and Admiral Cockbuni, with a loss of about oOO. defeated 7000 untrained Americans imder General binder, who, at the first attack, with a loss of only 76, fled in wild disorder, leaving Washington open to capture. It was formerh' a noted dueling-ground; and here, in 1820, Com- modore Decatur was mortally woimded by Com- modore Barron. Population, in 1890, 50.3; in inOO, 4(5,3. Consult ari;iclcs on the battle and on the Bladensburg dueling-gi-ounds in the Ma-ga- nine of American History, Vols. XV. and XXV. (Xew York. 1877-03).
BLAENAVON, bla-na'von (Cymr., Celt, hiacnc. source -f- aron, river), A coal-mining town and railway junction in ilonmouthshire, England, on the Avon, 4 'a miles southwest of Abergavennv (Jlap: England, C .5) . Population, in 1891. 11.400: in 1900. 10.900.
BLAEU, blou. BLAETIW, or BLAUW. A family of learned Dutch publisliers. Tlie founder of the firm was Willem Janszoon Blaeu (1571- 1C.3,S), a mathematician, born at Alkmaar, Hol- land. He was a pupil in astronomy of Tycho Bralie, and secured a considerable reputation by publishing terrestrial and celestial globes, excel- ling in beauty and accuracy everything that had preceded them. The Voii/s Atlas (6 vols., 1634- 02) is his principal work. His sons Cornelius (died 1650) and .Joan (died 1673) carried on his business together until the death of Cor- nelius. Their Atlas Major (11 vols., 1662) is a splendid work, and the maps are valuable from the light they throw on local history. Two of Joan's sons carried on their father's business until about 1700. Some of their classical publi- cations, especially Cicero's Orations (1699), are still highly prized. Consult Baudet, Leven en irerA-CH ran ^'i^cm J. Blaeu (Utrecht, 1871).
BLAGOVIESHTCHENSK, blii'g.-i - vygsh'- chensk ( Kuss., 'City of the Annunciation'; so named from the Church of the Annunciation). The capital of the Siberian region and Governor- Generalship of the Amur, situated on the left bank of the . uir, at its junction with the Seya, on the Manchurian frontier, and about 5000 miles east of Moscow (Map: Asia, M 3), It is one of the most ])rosperous and busy towns in East Siberia, and owes its pros))erity chiefly to the gold-mines in the vicinity. Only a military outpost in 185(i, it became in 1858 the capital of the Amur region, and is at present of consider- able commercial as well as strategical impor- tance. It was attacked by the Chinese in July, 1900. In 1808 it had but 3344 inhabitants; in 1889. 20,212, and at the census of 1897, 32,600 inhabitants.
BLAIKIE, bla'kl, William Gabden (1820-00). A Scottish divine and author. He was born at .l)crdeen. a son of James Blaikie. an advocate, and provost of .berdeen from 1833 to 1836. Educated at the universities of Aberdeen and Edinburgh, he was ordained minister of the
