strument used for holding horses by the nose when an operation is to be performed.

Bar'olite (Gr. heavy stone), a poisonous mineral in lead veins, the carbonate of barytes, containing 80 per cent. of barytes, and 20 per cent. of carbonic acid; sp. gr. 4.3. Barometer (Gr. weight measurer), an instrument for measuring the weight or pressure of the atmosphere, and showing the changes of the weather. It is a glass tube filled with mercury, hermetically sealed at one end; the other open, and immerged in a basin of stagnant mercury; so that, as the weight of the atmosphere diminishes, the mercury in the tube descends; and as it increases the mercury ascends, the column of mercury suspended in the tube being always equal to the weight of the incumbent atmosphere. Barometrograph is an instrument which of itself inscribes on paper the variations of atmospheric pressure.

Barometz, a vegetable production, the Scythian lamb, which consists of the prostrate heavy stem of the fern Aspidium barometz, which has the appearance of a crouching animal. Bar'oscope (Gr.), an instrument to show the weight of the atmosphere. Barose'lenite (Gr. baros weight, and selenite), in chemistry, the sulphate of barytes, heavy spar, which occurs in various rocks, both igneous and stratified.

Barras, the resin which exudes from wounds made in the bark of fir trees. Barry, in heraldry, a field divided by horizontal lines into four or more parts.

Barsowite (Russ.), a snow-white mineral, so named from Barswski, in the Ural Mountains, where it occurs. With borax, it fuses into a transparent glass. Its constituent parts are silex, alumina, and lime.-Dana. Barwood, a red dye-wood produced in Africa.

Baryphonia (Gr. barys, and phone voice), in pathology, difficulty of pronunciation.

Barystron'tianite (Gr. barys, and strontian), a mineral of a greyish-white colour, which occurs at Stromness, and in the Orkneys; hence called Stromnite.

Baryta, or Bary'tes (Gr. barys heavy), in mineralogy, a ponderous alkaline earth; an oxide of barium, so called from its great density. It is of various colours, but generally of reddish white; sp. gr. 441-4.67. Baryto-calcite (Gr. barys, and Lat. calx chalk), a crystallized mineral of a

yellowish or greyish colour, consisting of baryta and carbonate of lime: sp. gr. 3.6.

Basalt, a greyish-black mineral, of igneous or volcanic origin, occurring in globular masses, composed of concentric layers. The Giant's Causeway and the island of Staffa, with its celebrated excavation called Fingal's Cave, are remarkable examples of its columnar structure. Basal'tine, a mineral with a foliated texture; basaltic hornblende, of a dark green or yellowish green colour; it consists of silica, alumina, iron, lime, and magnesia.

Bas'anite (Gr. touchstone), in mineralogy, a variety of siliceous slate, called Lydian stone, from its being used as a test in determining the purity of gold by the colour of the streak.

Bascule (Fr.), in military science, the lever which serves to lift a drawbridge, the fore part being called the flèche, and the hind part the beauche Base (Gr. and Lat. basis; Fr. bas; Ital. basso), a term of frequent occurrence in science and art.-In chemistry, it is applied to all substances capable of saturating acids, and thus constituting neutral salts, as the metallic oxides, ammonia, and morphia.-In medicine, the constituent principle of a compound body or medicine.In geometry, it is the lowest side of the perimeter of a figure. In conic sections, it is a right line in the hyperbola and parabola, arising from the common intersection of the second plane and the base of a cone.In architecture, it is the lowest part of a column and pedestal.-In fortification, the exterior side of the polygon. In music, it is often called bass, the lowest part in a concert, either vocal or instrumental. -In military science, the base of operations is that line of frontier or country occupied by troops, from which military operations advance, and munitions are supplied, and on which a retreat may be made when needful.

Basement, in architecture, the lowest story of a building on which an order is placed, with a base or plinth, die and cornice.

Basic (Lat. basis), in chemistry, compounds having a large proportion of base.

Basil, in botany, a name of the genus Ocymum, one of the species of which is much used for seasoning in the culinary art.

Bas'ilar, or Bas'ilary (Lat. basis), in anatomy, belonging to the base of

the skull. Arteria basilaris, basilar or basilary artery, is that artery which results from the union of the two vertebral arteries, so termed because it lies upon the basilary process of the occipital base. In botany, the term is applied to any part placed at or near the base of another.

Basil'ica (Gr. royal), in anatomy, the anterior part of the axillary vein, running the entire length of the arm. -In ancient architecture, the court or public hall in which princes and magistrates sat to administer justice. Basilis'cus (Gr.), in herpetology, a genus of saurian reptiles, the basilisk, belonging to the Iguana family. In astronomy, a star of the first magnitude, in the constellation Leo.-In anatomy, applied to parts supposed to be very important in their functions; and in pharmacy, to compositions highly esteemed for their superior virtues in curing cutaneous or other disorders, as the ointment Basilicon. Basin (Fr.), in geology, a hollow tract of country, filled with a series of aqueous deposits, the strata of which have generally a dip in a central direction. In geography, that portion of the country which is drained by a river and its tributaries.

Basi-occipital (Lat. basis, and occiput the back of the skull), in anatomy, a bone of the head of lower vertebrate animals.

Basis (Lat.), in architecture, the pedestal of a column. In anatomy, basis cordis is the superior part of the heart, to distinguish it from its apex or small point; basis cerebri, the lower and posterior part of the brain. In pharmacy and medicine, the principal ingredient in a composition. In chemistry, a term applied to all the metals, alkalies, and other bodies which unite with acids or gases.

Bas-relief, or Basso-relie'vo (Ital.), in sculpture, low relief, or the figures which do not stand out prominently from the ground. When the figures are prominently raised, they are said to be in alto-relievo.

Bass, Basso (Fr. basse; Ital. basso), in music, the deepest part of harmony, and that which gives concord to the different parts of a concert. It is played on the largest pipes or strings of an instrument, as the organ, lute, &c.-Basso, in choral score, is generally placed against the stave of the instrumental bass in preference to that of the vocal bass.- (Busby.) Thorough bass is continued bass; the fundamental bass continued throughout a composition; also, the accom

paniment of a continued bass, marked by figures placed over or under the notes of the instrumental bass-staff. 2 -Basso concertante is the bass of the little chorus. - Basso repieno is the bass of the grand chorus; and basso continuo, that part of a composition which is set for an organ.-Basso-dicamera is an instrument for performing double bass.-Bass-clef is the character placed at the beginning of a stave, in which the bass or lower notes of a composition are placed, and serving to determine the pitch and names of those notes. Bassetto, the diminutive of basso, sometimes applied to the tenor violin.

Bassoon (Fr.), a musical wind instrument, serving as the proper bass to the oboe and clarionet. Bastion (Fr.), in fortification, a strong projecting mass of masonry at the angles of a fortified work. -A bastion has two faces, and an opening towards the centre, called the gorge. -A flat bastion is made in the middle of the curtain, when it is too long to be defended by the bastions in its extremes. A demi-bastion has only one face, with one flank and a demigorge. A double bastion is erected on the plane of another.

Mil. Cycl.

one

Basyle (Gr. basis, and yle matter), in chemistry, a term applied to the metallic radical of a salt; thus the base of a sulphate of soda is soda, or oxide of sodium, and the basyle is sodium.

-Graham.

Baťardeau (Fr.), in fortification, a wall across a wet ditch, with sluices in it. -In civil achitecture, a coffer-dam for building the piers of a bridge. Bath, in chemistry, a vessel filled with either water or sand, which encloses another vessel containing a substance to be heated or dried.-Bath-metal is a metallic alloy, composed of zinc and brass.

Bath O'olite (Bath, and Gr. egg-stone), in geology, a stone belonging to the Oolitic formation, much used in building and architectural works. Bath-stone, a kind of limestone, much used in building, quarries of which are found near Bath, in Somersetshire. Batolite (Fr. bâton a staff, and lithos a stone), in geology, a genus of cylindrical bivalve shells, some of considerable length, which form masses of rock in the High Alps. Baton (Fr.), in heraldry, the mark of illegitimate descent. Batrac'hia, or Batrac'hians (Gr. batrazoology, an order of

chos a frogmprising frogs, toads, and

others, which have naked skins

external branchiæ, or gills, in the early state.- Batrachite is a fossil batrachian, which occurs in the tertiary lignite, or brown coal-beds of the valley of the Rhine.

Battery, a term of frequent use in physical and practical science.-In electricity, a battery consists of a combination of glasses with cooled surfaces, so connected that they may be charged at once, and discharged by a common conductor.-A galvanic battery or pile is an apparatus employed for accumulating the electric fluid, by means of plates of zinc and copper arranged alternately, connected together, and placed in diluted nitric acid; invented by Volta. Various improvements have been effected in electric batteries by Wollaston, Daniel, Grove, Smee, Wheatstone, and others. The battery invented by Professor Daniel consists of a certain number of cylindrical vessels of copper, open at the top, about sixteen inches high, and three inches diameter, and containing a saturated solution of sulphate of copper, with a little vitriolic acid. - In military science, batteries are the implements of war with which a besieged place is battered. They are of various kinds. A mortar battery is sunk into the ground, and has embrasures; battery d'enfilade is one formed to sweep the whole length of a given straight line; cross batteries are two batteries so situated as to play on the same object at a given angle; a battery en écharpe plays in an oblique direction; battery de revers plays on the back of the enemy. Camerade battery is one in which several guns are engaged in firing on the same object at the same time. To batter in breach is to direct a heavy cannonade of many pieces on one part of the revêtement from the third parallel.

Battlement (Fr. bâtiment), in military science, a breast-work or parapet raised round the top of a building, with embrasures or interstices to look through, and at the same time assail and annoy a besieging force.

Battuta (Ital.), in music, the motion of the foot or hand in beating time and guiding the performers.

Bay (Sp. bahia), in architecture, a term applied to a compartment between the ribs of a groined roof; also to the square between the buttresses of a wall, or between the mullions of a window. In naval architecture, the bay is the part on each side between decks situated between the bitts. -In geography, a bay (Ital. baia) is a portion of the sea extending into the

land less than a gulf, and larger than a creck, the shore of which is usually of a curved appearance.-Bay-salt is a salt produced by exposure of seawater to evaporation from the action of the atmosphere or the rays of the

sun.

Bdella (Gr. bdello), a genus of Annelides, furnished with eight eyes, inhabitants of the Nile; also a genus of Arachnides, found under stones. Bdellium (Lat. from Gr. bdellion), a resinous juice or gum resin, exuding from an oriental tree, supposed to be the Balsamodendron (Balsam tree). Bend, in architecture, a kind of circular moulding, frequently used on the fascia of an architrave, and also in the mouldings of doors, imposts, cornices, &c. There are various distinctive names, as quirk bead, cock bead, &c., which are more of a technical than scientific character.

Beak (Fr. bec), in architecture, a small fillet left on the edge of a larmier, forming a canal behind, to prevent the water from running down the lower bed of the cornice. In naval architecture, that part situated before the forecastle, on the outside of the ship, fastened to the stem, and supported by the main knee.-In farriery, a little shoe about an inch long at the toe, turned up and fastened in upon the forepart of the hoof. Beam Compasses, in geometry and mathematics, an instrument with sliding sockets, and several shifting points, for the purpose of drawing circles with very long radii.

Beam Tree, a species of wild pear tree, the Pyrus aria, so called from the wood being much used in the manufacturing of machine cogs and axle

trees.

Bear, in astronomy, a northern constellation; the Ursus Major and Minor, the names of the Great and Little Bear.

Bearing, in geography and navigation, the point of the compass that one place bears or stands off from another. In architecture, the length or distance which the ends of a piece of timber are inserted into walls or piers. Bearing wall, or partition, is a wall which is built upon the solid, and is made to support another wall or partition, either in the same or in a transverse direction. In heraldry, coats of arms or figures of armories. Beau-ide'al (Fr.), in the fine arts, the conception of perfect beauty, as represented in painting, sculpture, or architecture; the beautiful in nature. Beca-fico (Sp.), in ornithology, a beau

tiful little bird, that sings like a nightingale, and feeds on figs; the Sylvia hortensis of naturalists.

Bed Mouldings, in architecture, those mouldings which are between the corona and frieze of all the orders. Bee, in entomology, the common name of the genus Apis, a honey-producing hymenopterous insect, celebrated for the wonderful accuracy of its architecture, its instincts, and the valuable products of its industry.-Bee-bread is a term applied to the pollen of flowers, from which the bee supplics its young with food.

Beetle (Sax. bitel), a coleopterous insect with four wings, of which there are numerous species. (See Coleoptera.)

Begonia'cese, in botany, a nat. order of endogenous plants, the flowers of which are unisexual; the type and only genus of this order is the Begonia.

Behen (Arab.), an old name given to the Cucubalus behen of British botanists; Centaurea behen, which is aromatic and astringent; and to Statice limonium, used as an astrin gent.

Belem'nite (Gr. belemnon a dart), in geology, a fossil shell (Arrow-head, or Thunderstone) of the Cephalopod order, found in the chalk or limestone formation. It is of a conical form, and divided into chambers, perforated by a siphuncle or pipe, and inserted into a laminar, solid, fusiform sheath.

Bell, in architecture, the naked vase or corbeille round which the foliage and volutes of the Corinthian and composite capitals are arranged.-Bell roof is a roof, the vertical section of which is concave at bottom and convex at the top.

Belladonna (Ital. fair lady), in botany, a poisonous perennial plant, the Deadly Nightshade; a species of Amaryllis. Belladonna lily, a liliaceous plant, with beautiful delicate flowers.

Bellatrix (Lat. a female warrior), in astronomy, a star of the first magnitude, in the constellation Orion. Bellerophon, in palæontology, a genus of fossil shells found in the carboniferous limestone formation.

Bell-metal, in metallurgy, a metallic composition, consisting of 8 parts of copper and 2 of tin. In small ringing bells, zinc is sometimes a constituent.

Bello'na, in astronomy, one of the recently discovered planets, first observed by Luther in 1854. Its mean distance from the sun is 264,650,000

Bellusæ (Lat. bellua, a large beast), in zoology, an order of Mammiferæ now comprehended under the Pachydermata of Cuvier's system.

Belly. In music, the belly of the harp sichord or piano-forte (as described by Dr. Busby) is that smooth thin boarding over which the strings are distended, and which, by its vibration, materially contributes to the tone. In a double bass, violoncello, violin, and all instruments performed on with the bow, it is that part of the body which lies immediately under the strings.

Belo'ne (Gr. a needle), in ichthyology, a sub-genus of the Pike family, one of which is known as the Needle or Garfish.

Belop'tera (Gr. a winged javelin), in geology, a genus of fossil shells, found in the London clay, with wingshaped appendages.

Belostoma (Gr. belos a javelin, and stoma a mouth), a genus of hemip. terous insects, of the family Hydro

corisæ.

Belt, in astronomy, a name applied to certain zones seen to pass across the surface and parallel to the equator of the planet Jupiter. Belvedere (Ital. a fine view), in Italian architecture, an ornamental erection at the top of a mansion, constructed for the purpose of obtaining an extensive view of the surrounding country.

Belvisia'ceæ, a nat. order of plants, of which Belvisia cærulea is the type, a plant which is loaded with large blue flowers, and grows about seven feet high.

Bembicid'eæ (Gr. bembex a top), a family of coleopterous insects, of which the Bembex, belonging to the Fossores, or burrowing wasps, is the type. Ben Marca'to (Ital.), in music, an expression denoting that a passage is to be executed in a clear and pointed

manner.

Ben Oil, an oil expressed from the decorticated seeds of Guitandina moringa, used in the manufacture of scented oils.

Bengal Lights, in pyrotechny, a species of firework, used as signals by night or otherwise, producing a steady and very vivid blue-coloured fire. The ingredients are 28 oz. of sulphur, 12 oz. of saltpetre, and 25 oz. of realgar. Ben'zamide, in chemistry, a compound of benzoic acid and amide, I atom each; it forms colourless transparent crystals.

Benzhydramide, in chemistry, a compound consisting of 42 atoms of carbon, 18 of hydrogen, and 2 of nitrogen.

Benzile, in chemistry, a compound consisting of 14 atoms of carbon, 5 of hydrogen, and 2 of oxygen.-Hydrocyanite of benzile is a chemical product obtained from a hot solution of benzine and prussic acid, forming large colourless crystals, and consisting of benzile and prussic acid, I atom each. Benzilic acid is a compound consisting of 28 atoms of carbon, 11 of hydrogen, 5 of oxygen, and I of water.

Ben'zimede, in chemistry, an ingredient of the raw oil of bitter almonds, forming very white and flocky inodorous pearly needles and laminæ. It consists of carbon, hydrogen, oxygen, and nitrogen.

Benzoate, in chemistry, a combination of benzoic acid with the metallic oxides.

Benzo'ic Ether, in chemistry, a colourless oily liquid, with a feeble aromatic smell and pungent taste.

Benzoin, in chemistry, a concrete resinous juice of the East Indian tree, Styrax benzoin.-Flowers of benzoin are white needle-like prisms, with a soft silky lustre and pungent taste.Hydrocyanite of benzoin is a chemical product from a mixture of oil of bitter almonds, prussic acid, caustic potash, and alcohol. Benzoic acid unites with the earthy and alkaline bases, and with the metallic oxides. Benzole, or Benzine, in chemistry, a colourless liquid of agreeable odour, which freezes at 32° in a crystalline mass resembling loaf-sugar.

Benzone, in chemistry, a colourless oily liquid, which consists of 13 atoms of carbon, 5 of hydrogen, and I of oxygen.

Benzule, in chemistry, a compound obtained from the volatile oil of the bitter almond. It has various compounds; as, Bromide of benzule, I atom of benzule, and I of bromine; atomic weight = 185.03;-Cyanogen of benzule, I atom of benzule, and I of cyanogen; atomic weight = 133.07;-Hydruret of benzule, I atom of benzule, and I of hydrogen; atomic weight = 142°10;-Iodide of benzule, I atom of benzule, and I of iodine; atomic weight=232.98;-Sulphuret of benzule, I atom of benzule, and I of sulphur; atomic weight = 122.78. Berbera'ceæ, or Berberid'eæ (Arab.), in botany, a nat. order of exogenous plants, of which the Barberry is the type. It is an elegant shrub, which bears yellow flowers and red acid berries.-Berberin is the bitter principle, obtained from barberry and its root, and is extensively used in dyeing yellow.

Bergamite, in mineralogy, a variety of

scapolite, found in Norway. Bergamot, the fragrant fruit of the bergamot orange tree, from the rind of which an essential oil is obtained. Bergmehl (Swed. mountain meal), in geology, a whitish, mealy-looking earth, containing infusorial animalcules.

Berme (Fr.), in fortification, a space of ground between the foot of the rampart and the side of the moat, to prevent the earth from falling down. Ber'oë, in ichthyology, a genus of very minute radiated animals, with globular gelatinous bodies, remarkable for emitting a phosphoric light. Ber'thierite (so called from Prof. Berthier, of Paris), a mineral found in lamellar masses, of a dark grey steel colour, and consisting of antimony, sulphur, iron, and zinc.

Beryl (Lat. beryllus), in mineralogy, a gem or precious stone. The aquamarina is a beryl, which is transparent, and consists of silica, alumina, glucina, oxide of iron, and oxide of columbium.

Beryx, a genus of fishes, of the subfamily Percidæ, or Perches.

Ber'zeline, in mineralogy, the seleniuret of copper; also, surname of a mineral found in Italy.

Beta-orceine, a colouring matter obtained from the beet-root, composed of carbon, hydrogen, and protoxide of nitrogen.

Betel, an evergreen shrub of the East Indies, the Piper betel, the leaf of which forms a hot and acrid masticatory, in almost universal use in India and the Malayan Archipelago. It is aromatic and stomachic.-Betel nut, or Areca, is used in dyeing cottons. Bethylus, in entomology, a genus of hymenopterous insects. In ornithology, a genus of passerine birds. Beton (Fr.), in the arts, a kind of concrete or hydraulic cement, mixed with gravel, pebbles, &c., and used in submarine works as a foundation. Beton'ica, a genus of labiate plants (Betony), consisting of perennial deciduous herbs.

Betula'ceæ, or Betulin'eæ (Celtic beithe), a division of the nat. order Amentaceae, of which the Betula (including the alder and birch) is the type.

Bet'uline, in botany, a colourless resinous camphor (the Betula nigra), extracted from the bark of the black birch.

Beu'danlite, a mineral found associated with brown iron ore in the district of Nassau, and consisting of oxides of lead and iron.