ORENSE 



ORGAN 



637 



town possesses an arsenal and two military schools. 

 Pop. (1882) 42,123. The government has an area 

 of 73,794 sq. in. and a pop. of 1,198,360, of very 

 mixed races, Bashkirs (246,000) and Cossacks 

 (229,000) predominating. 



Orense, capital of a Galician province of Spain, 

 near the frontier of Portugal, on tlie left bank of 

 the Minlio, and 60 miles from its mouth. It has 

 hot sulphurous springs, and manufactures woollens, 

 linens, and chocolate. Pop. 13,291. 



Oreodaplllie, a genus of trees of the natural 

 order Laiiracea;, sometimes called Mountain Laurel. 

 O. opifera is a native of the countries on the lower 

 part of the Amazon. A volatile oil obtained from 

 the bark is used as a liniment, and when kept for 

 a short time deposits a great quantity of camphor. 

 0. cupularis is a very large tree with strong-scented 

 wood, the bark of which yields the cinnamon of 

 Mauritius. It grows also in Bourlion and Mada- 

 gascar. 0. fceteiu, a native of the Canaries, has 

 wood (Til-wood) of a most disagreeable odour. 0. 

 bullata, found at the Cape of Good Hope, is also 

 remarkable for the disagreeable odour of its wood, 

 the Stink-wood of the colonists ; but it is hard, 

 durable, beautiful, takes an excellent polish, and 

 is used in shipbuilding. 



Oreodonts. an extinct family of ungulates, the 

 remains of which occur in the Tertiary deposits of 

 North America. 



Orestes, son of Agamemnon and Clyteemnestra. 

 M'hen liis father was murdered by his mother and 

 her paramour ./Egisthus -he was saved by his sister 

 Electra, who sent him secretly to Pliocis to the 

 cuiirt of Strophius, husband of Agamemnon's sister. 

 Here he formed a romantic friendship with the king's 

 eon, Pylades, and as soon as lie had grown up the 

 pair went secretly to Argos, and slew ClyUcmnestra 

 ami /Egistlius. Madness seized him after the 

 matricide, and he Hed from land to land, ever 

 haunted by the avenging Erinnyes or Furies. At 

 Athens, whither lie had lied by advice of Apollo, 

 he was purged of guilt by the Areopagus. Learn- 

 ing from Apollo, according to another story, that 

 he could only recover from his madness by carry- 

 ing off the statue of Artemis from the Tauric 

 Cliereonesiis, he journeyed thither along with 

 Pylades, but the fnends were seized by the natives 

 to be sacrificed to Artemis. Her priestess Iphigenia 

 recognised her brother in Orestes, and all three 

 esca|>ed together, carrying the statue with them. 

 Orestes recovered his father's kingdom at Mycemu, 

 slew Neoptolemus, and married his wife Hermione, 

 who had been formerly promised to himself. The 

 story of Orestes afforded a favourite theme to the 

 great tragedians to jEschylus in the extant 

 trilogy, the Oretteia ; to Sophocles in his Electra ; 

 to Enripidci in his OrettesnnA Electra. See Becker, 

 Die Oretti-*age der Griecken ( 1858). 

 Orl'.-i. See EDESSA. 



Orflla, MATHIEU JOSEPH BONAVENTURE, 

 founder of the science of toxicology, was born at 

 Mahon in Minorca, 24th April 1787, and studied at 

 Valencia, Barcelona, and Paris (wlijther he was 

 gent by the junta of his province). In October 

 181 1 he received the degree of Doctor of Medicine, 

 and immediately commenced a private course of 

 lectures on chemistry, botany, and anatomy, which 

 was largely attended, and, along with his successful 

 practice, soon rendered him famous. In 1813 

 appeared the first edition of his celebrated work on 

 poisons, entitled Traiti de Toxir.nl/agie Generate 

 ( Paris). In 1819 he was created a citizen of France, 

 and became professor of Jurisprudence ; ami in 1823 

 he was transferred to the chair of Chemistry, to 

 which in 1831 was added the deanship of the 

 faculty. On the outbreak of the revolution of 

 1848 he was deprived of his place in the medical 



faculty on account of his conservative opinions, 

 but retained his professorship. He died at Paris, 

 March 12, 1853. Other works were on medical 

 chemistry (1817) and on forensic medicine (1825). 

 He also contributed largely to various journals, 

 dictionaries, and encyclopaedias. 



Orford. See WALPOLE. 



(Gr. organon, 'an instrument '), a 

 musical instrument played by keys, and generally 

 also by pedals, and consisting of metal ami wood 

 pipes, which sound by wind stored in bellows, and 

 admitted into them at will. The following descrip- 

 tion is necessarily restricted to the most funda- 

 mental arrangements of this very complicated 

 instrument. As met with in cathedrals and large 

 churches, the organ comprises four or sometimes 

 five departments, each in most respects a separate 

 instrument with its own mechanism, called respec- 

 tively the great-organ, the choir-organ, the swell- 

 organ, the pedal-organ, and sometimes the solo- 

 ni-i/iin. Each has its own keyboard, but the 

 different keylx>ards are brought into juxtaposition, 

 so as to be under the control of one performer. 

 Keylmards played by the hands are called manuals ; 

 by the feet, pedals. Three manuals, belonging to 

 the choir, great, and swell organs respectively, rise 

 above each other like steps in front of the per- 

 former, while the pedals by which the pedal-organ 

 is played are placed on a level with his feet. The 

 condensed air supplied by the bellows is conveyed 

 through a wind-trunk into a wind-chest. Each 

 department of the organ, it may be mentioned, has 

 its wind-chest. Attached to the upper part of the 

 wind-chest is the upper board, an ingenious con- 

 trivance for conveying the wind at pleasure to any 

 individual pipe, or pipes, exclusively of the rest. 

 In the upper board are set the pipes, of which a 

 number of different quality, ranged behind each 

 other, lielong to each note. Beneath the upper 

 board is a row of parallel grooves, running horizon- 

 tally backwards, corresponding each to one of the 

 keys of the instrument. On any of the keys Ix-ing 

 pressed down, a valve is opened which supplies 

 wind to the groove belonging to it. The various 

 pipes of each key stand in a fine directly above its 

 groove, and the upper surface of the groove is per- 

 forated with holes bored upwards to them. Were 

 this the whole mechanism of the sound-l>oard the 

 wind on entering any groove would penetrate all 

 the pipes of that groove ; there is, however, in the 

 upper board another series of horizontal grooves at 

 right angles to those beneath, supplied with cross- 

 slides, which can be drawn out or pushed in at 

 pleasure by a mechanism worked by the draw-stops 

 placed within the player's reach. Each slide is 

 perforated with holes, which, when it is drawn out, 

 complete the communication lietween the wind- 

 chest and the pipes : the communication with 

 the pipes immediately above any slide being, 

 on the other hand, closed up when the slide 

 is pushed in. The pipes above each slide form 

 a continuous set of one particular quality, and 

 each set of pipes is called a stop. Each depart- 

 ment of the organ is supplied with a number of 

 stops, producing sounds of different quality. The 

 great-organ, some of whose pipes appear as show- 

 pipes in front of the instrument, contains the 

 main body and force of the organ. Behind it 

 stands the choir-organ, whose tones are less 

 powerful, and more fitted to accompany the voice. 

 Above the choir-organ is the swell-organ, whose 

 pipes are enclosed in a wooden box with a front of 

 louvre-lxmrds like Venetian blinds, which may be 

 made to open and shut by a pedal, with a view of 

 producing crescendo and diminuendo effects. The 

 pedal-organ is sometimes placed in an entire state 

 behind the choir-organ, and sometimes divided and 



