tained from stick-lac.-Laccine, a brittle, yellow substance obtained from shell-lac.

Lacer'ta (Lat. a lizard), in zoology, a genus of slender-tongued Lizards.In astronomy, a constellation of the northern hemisphere.

Lacertidæ (Lat.), in herpetology, a family of the order Sauria, including the genera Lacerta and Monitor. Lacertil'ia (Lat.), an order of reptiles, of which the Lizard is the type. Lach'rymal Canals, in physiology, the ducts which convey the tears from the eye to the nasal ducts.-Lachrymal ducts are the small tubes which convey the tears from the lachrymal glands to the eyes. - Lachrymal gland, the gland which secretes the tears.

Lacquer, a yellow varnish, consisting chiefly of a solution of pale shell-lac in alcohol, and applied to tin, brass, and other metals to preserve them from tarnishing, and to improve their colour.-Lacquered ware are those articles varnished with lacquer.

Lacrimo'so (Ital.), in music, a term signifying that the passage is to be performed in a plaintive and sorrowful manner.

Lac'tarine (Lat. lac milk), in the arts, a preparation of caseine from milk, extensively used by calico-printers.Lactine is a sweetish substance existing in milk.

Lactates (Lat. lac), salts formed of lactic acid with a salifiable base. In the neutral lactates the hydratic water of the acid is replaced by one equivalent of metallic oxide.

Lac'teals (Lat.), in anatomy, the absorbents of the mesentery, which convey the milky fluid from the small intestines into the thoracic duct. Lactine, a sweetish substance existing in milk; sugar of milk.

Lactometer (Lat. lac, and Gr. metron a measure), a glass tube for ascertaining the proportion of cream and milk, and also for determining the specific gravity of milk.

Lac'toscope (Lat. lac, and Gr. skopeo to view), an optical instrument for ascertaining the opacity of milk and the richness of cream.

Lactua'rium (Lat.), the inspissated milky juice of the Lactuca virosa..or Acid Lettuce.-Lactucic acid is the name of the acid found in the juice of the plant.-Lactucine is the active principle of the Lactuarium, which forms yellowish, indistinct crystals, that have a strong, persistent, bitter

taste.

Lacu'næ (Lat. gaps), in anatomy, small cavities in some of the mucous mem

branes, in which the process of secretion is carried on.

Lacu'nar (Lat.), in architecture, a ceiling or soffit with hollow ornamentation. Lacunose' (Lat. lacunosus dotted or pitted), in botany and zoology, having depressions or excavations on the surface.

Lacus'trine (Lat. belonging to a lake).Lacustrine deposits, in geology, are certain fresh-water beds deposited by lakes, and confined to the more recent formations.

Ladle, in gunnery, a copper instrument used for drawing the charge of a great gun; also a long staff with a hollow place at the end of it, which will hold as much as the proper charge of the piece of ordnance it belongs to.

Læmod'ipods (Gr. laimos the throat, and podes feet), in malacology, an order of Crustacea, in which the head is confluent with the first segment of the thorax, and supports the four anterior feet.

Lætitia, the name of one of the newlydiscovered planets, first observed in 1856. Lagophthalmy (Gr. lagos a hare, and ophthalmos an eye), a disease of the eye, in which it cannot be shut, but remains open during sleep, as in the case of the hare.

Lake (Germ. lache, from Lat. lacus), in painting, a red water-colour; a term applied to certain colours produced by the combination of vegetable colouring matter with the peroxide of tin, and with similar oxides, which are intermediate between acids and alkalies.

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Lamboid, or Lamboi'dal (Gr. lambda), in anatomy, an epithet which designates, from its similarity to the Greek letter A, the suture which unites the occipital and parietal bones, now more correctly termed the occipito-parietal suture. Lamellibran'chiates (Lat. lamella thin plate, and branchiæ gills), an order of Mollusca, in which the branchiæ occur in the form of large semicircular layers. Lamel'licorns (Lat. lamella, and cornea a horn), in entomology, a family of pentamerous Coleoptera, in which the antennæ are inserted into a deep fossula, under the lateral margin of the head.-Cuvier. Lamelliros'trals (Lat. lamella, and rostrum a beak), in ornithology, a tribe of swimming birds, the fourth in Cuvier's system. Lam'ide, a family of coleopterous insects, of which the Lamia is the type. Lam'inar, arranged in plates or scales.

Lamp (Lat. lampas). -Safety lamp is a lamp invented by Sir Humphry Davy to prevent the explosion of firedamp or inflammable air in coal mines.

Lamp-black (Lat. fuligo lampadum), a species of charcoal, of which the finest sort is produced by collecting the smoke from a lamp; but it is generally obtained by burning resinous substances in furnaces, and collecting the soot produced on cloths in a close chamber.

Lamprotorni'ne (Gr. lampros brilliant, and ornithos a bird), in ornithology, a family of Sturnidæ, or Starlings (the Grackles), of which the Lamprotornis is the type.

Lampyr'idæ (Gr. lampyris the glowworm), a family of Serricornes, of which the Lampyris, a genus of coleopterous insects, is the type. The light which it diffuses is of a lambent, electric, greenish colour, which the insect can vary or suspend at pleasure. Lanark'ite, in mineralogy, a sulphocarbonate of lead found at Leadhills, in Lanarkshire, of a greenish or greyish colour: sp. gr. 8.8; H-2-5. Lan'caster Gun, a piece of ordnance with an oval bore and a very long range; so named after the inventor. Lan'ceolate, or Lanceolated (Lat. lanceolatus), in botany, shaped like a lance. In entomology, applied to an insect when the base is not so broad as the centre, and the lateral margins gradually taper to the apex.--In conchology, applied to a shell of an oblong shape, and tapering gradually to each end.

Lancet (Fr.), a small, pointed, surgical instrument, used for letting blood, &c.-Lancet-arch, in architecture, an arch, the head of which is like the point of a lancet, and usually applied to long, narrow windows.

Land (Sax., Gothic, Swed., &c.), the solid matter which constitutes the fixed part of the surface of the globe. It forms a prefix to a variety of scientific compounds; as, Landsprings, sources of water which only come into action after heavy rains; -Land-flood, an overflowing of land by water;-Land-slip, part of an eminence which slips down in consequence of being undermined, and its support swept away;-Land-scurvy, an affection consisting of circular spots, stripes, and patches, scattered over the arms, thighs, and trunk-the Purpura hæmorrhagica;-Landrail, the migratory bird Rallus crex, called also the Corncrake, from its peculiar cry;-Land-force, an army or body of troops serving on land.

Landscape Gardening, in horticulture, the art of scientifically laying out grounds so as to produce the effect of natural landscape. Landsturm (Germ.), in military affairs, a local militia of Prussia, which is never called from its own district but in case of actual invasion. Langrage, Langrel, in naval warfare, a kind of chain-shot, formed of bolts, nails, &c., tied together.

Languen'te (Ital.), in music, noting a soft and languishing manner. Laniar'iform (Lat. lanio to tear), shaped like the canine teeth of carnivorous animals.

Lan'idæ, in ornithology, a family of birds known by the name of Shrikes, of which Lanius, the Butcher Bird, is the type.

Lanta'nium (Gr. lanthano), in mineralogy, a metallic substance associated with the oxide of cerium. Lantern (Fr.), in architecture, a little turret or drum-shaped erection on the top of a dome.-Lantern-wheel, in mechanics, is a kind of pinion, having cylindrical teeth or bars, called trundles or spindles, on which the teeth of the main wheel acts.Magic lantern is an optical instrument, by which little painted images are represented so much magnified as to be accounted the effect of magic by the ignorant.

Lanu'go (Lat.), the first hair produced in the fœtus.

Lanyard, in nautology, a piece of line or rope for fastening the tackle of a ship.

Lap'arocele (Gr. lapara the loins, and kele hernia), in pathology, a rupture through the side of the belly.

Lapidification (Lat. lapis a stone, and fio to become), conversion into stone. Lapil'li (Lat. little stones), in geology, small volcanic cinders. Lapis (Lat. a stone), a term applied to various mineral substances, and from which there is a variety of scientific formations; as, Lapis Armenius, Armenian stone, from which the colour called blue bice is prepared ;L. atites, eagle-stone, a variety of iron ore; -L. bezoar, a concretion found in the stomachs of certain animals: the L. bezoar factitius consists of equal parts of Armenian bole and dried blood, with mucilage of gum tragacanth;-L.calaminaris, calamine, impure carbonate of zinc; -L. calcareus, limestone, consisting of carbonic acid and lime;-L. carpionum, a quadrangular flat bone; -L.contrayerva, the pulvis contrayervæ compositus;-L.dentalis. dentalium;--L.divinus, lapis ophthalmicus, nitrate of potassa; -L. hæmati tis, blood-stone; - L. Hibernicus, Irish slate;-L. lazuli, L. cæruleus, L. cyanus, azure-stone; a mineral from which the blue colour ultramarine is prepared; -L. Lydius, Lydian stone; a species of flinty slate; L. manati, manati - stone, the tooth of the sea-cow;-L. medicamentosus, a preparation of alum, litharge, Armenian bole, colcothar, vitriol, and vinegar, boiled to strong consistence;-L. nephriticus, a mineral, of which there are two kinds-common nephrite and axestone; - L. petracorius, perigordstone, used to colour glass black;L. prunella, sal prunellæ; - L. pumex, pumice-stone, which swims upon water.

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Laq'ueus Gut'teris (Lat.), in pathology, a malignant inflammation of the tonsils.

Larboard, in nautology, the left-hand side to a person on shipboard looking towards the head; opposed to starboard.- Larboard tack, so called when a ship is close hauled, with the wind on her larboard side.

Largo (Ital.), in music, a slow movement, one degree quicker than adagio. -Larghetto is a movement a little quicker than largo.

Lar'ide (Lat.), a sub-famıly of aquatic birds, of which the Larus, or Common Gull, is the type; fam. Alcadæ.

Lar'mier (Fr.), in comparative anatomy, a membranous sac which secretes a thick, blackish, and unctuous fluid, situated in an infra-orbitary depression of the maxillary bone.-In architecture, the flat jutting part of a cornice.

Lar'ride, in entomology, a family of hymenopterous insects, of the section Fossores, of which Larrus is the type.

Larva, pl. Larvæ (Lat.), a flying insect in a masked or caterpillar state; the second state of the insect.

Laryngis'mus (Gr. larynx), spasmodic action of the larynx.-Laryngitis, inflammation of the larynx. Laryngotomy, operation of opening the larynx.

Larynx (Gr.), in anatomy, the upper part of the trachea, a cartilaginous cavity, the superior opening of which is called the glottis.

Lateen Sail, in nautology, a triangular sail used by small vessels in the Mediterranean and Eastern seas.

Latent (Lat. lying concealed), in pathology, a term applied to diseases of obscure diagnosis; -in botany, to the vegetable embryo when described only by adventitious causes;-in chemis

try, when so intimately combined with bodies that its presence is not indicated by the thermometer.-Latent heat is that which is insensible to the thermometer, upon which the liquid and aëriform state of bodies depend. Laterite (Lat. later, lateris a brick), a mineral substance which forms an important ingredient in hydraulic

cement.

Latex (Lat.), in botany, the vital fluid of vegetables.

Latitude (Lat.), in geography, the distance of a place from the equator, north or south. In astronomy, the distance of a star north or south of the ecliptic.

Latrobite, a translucent mineral of a pale red colour, consisting of silica, alumina, lime, oxide of manganese, magnesia, potash, and water: sp. gr. 27-28; H=5.0-6.0.

Lau'danum (Lat.), in medicine, an extract of opium, tinctura opii. Laughing Gas, nitrous oxide, or protoxide of nitrogen, so called from the laughter it produces when inhaled.

Lau'monite, a soft mineral of a yellowish colour and pearly lustre, consisting of silica, alumina, lime, and water: sp. gr. 2.3.

Laura'cese (Lat.), a nat. order of Exogens, or evergreens, consisting of shrubs and trees, of which Laurus (the Laurel) is the genus. Laurel is the popular name of the two species of Cerasus-C. Lusitanica and C. lauro-cerasus, the Cherry or Common Laurel: order Amygdalaceæ. -Laurel-water is a distilled water from the leaves of Prunus lauro

cerasus.

Lava (Ital.), a stream of melted minerals discharged by volcanoes, and which flows down, and sometimes bursts through, the sides of volcanoes during an eruption. Laven'duline, a vitreous mineral, consisting of silica, alumina, lime, potash, and oxide of manganese: sp. gr. 27-28; H=5.0-6.0. Laxa'tor (Lat. laxo to loosen), in ana.. tomy, a term applied to certain muscles which relax, or make loose. Laz'ulite, a vitreous mineral of a pale blue colour of various shades; the lapis-lazuli, or azure-stone, consisting of phosphoric acid, alumina, magnesia, silica, protoxide of iron, and water: sp. gr. 3; H=5-5.5. Lead, in mineralogy, a soft, ductile, heavy metal, of a dull whitish colour, with a cast of blue: sp. gr. 11'38; equiv. 1036; symb. Pb. The following are some of the chemical compounds of lead :-Dinoxide = 213.2; peroxide = 119'6; protoxide 111'6; sesquioxide = 2312; chloride = 139°02; iodide = 229.9; bromide = 182'0; fluoride 122 28; sulphuret = 119.7.-Leads, in letter-press printing, are pieces of type-metal cast to specific thicknesses and lengths, lower than the types, so that they may leave an open space where placed. - Lead pencii, an instrument for drawing or making lines, made of plumbago, or black-lead.-Lead-shot, shot manufactured from lead.-Lead spar, a sulphate of lead.-Lead-wort, the common name for several species of plants belonging to the order Plumbaginaceæ.

Leda, in astronomy, the name of one of the newly-discovered planets, first observed by Chacornac in 1856. Its mean distance from the sun is 263,480,000 miles, and the time of its periodical revolution 4 years and 202 days.

Leelite, a silico-aluminous mineral, tinged by oxide of manganese: sp. gr. 2.60.

Lega'to (Ital.), in music, a term denoting that one note is tied to another, as indicated by these marks

Leggia'dro (Ital.), in music, a term deLoting that the passage is to be performed in a brisk and lively manner. Legume, Legu'men (Lat. pulse), in botany, any kind of fruit like the pod of a pea which opens at the back and front.

Lehun'tite (in honour of Captain Le Hunt), a flesh-coloured mineral; a compact zeolite, consisting of silica, alumina, soda, lime, and water: sp. gr. 195; H = 3.75.

Lemma (Gr.), in geometry and mathematics, an assumption, or preparatory proposition, for the purpose of facilitating the demonstration of a theorem.

Lemming, the Lapland Marmot, a rodent quadruped as large as a rat, with black and yellow fur. The Lemmings are very abundant in the north of Europe, and on the shores of the Arctic Sea, and are remarkable for their occasional migrations in immense numbers, during which they march in a straight line across rivers, lakes, &c.

Lem'nian, an epithet applied to a kind of siliceous earth found in the island of Lemnos.

Lemnis'cate, in geometry, a curve in the form of the figure 8.

Lemon, an acid fruit of the Lemon tree, the Citrus medica, of Persia.-Essential salt of lemon, the binoxalate of potash, used in removing moulds and stains from linen.

Lemu'ridæ (Lat.), in zoology, a family of quadrumanous animals, of which the Lemur is the type and genus.

Lens (Lat.), in physics, any transparent medium of certain forms. In optics, a thin piece of glass, or other transparent substance, having on both sides polished spherical surfaces, which have the property of changing the direction of the rays of light passing through it. There are various forms of lens; as, the convex lens, which converges the rays; the concave, which disperses them; the plano-convex, having one surface plane and the other convex; the double convex, having both sides convex; the plano-concave, having one surface plane and the other concave; the double concave, having two concave surfaces; the meniscus, having one side concave and the other convex. The plural, lenses, is a general term applied to magnifyingglasses for conveying light to a focus in a telescope and other optical in

struments.

Len'tement (Fr.), in music, a word signifying that the movement to which it is prefixed is to be slowly performed.

Lentibula'ree (Lat.), in botany, a nat. order of exogenous plants, living in water or marshes, of which the Lentibularia is the genus.

Lentic'ular (Lat. lens), doubly convex; of the form of a lens. In mineralogy, lenticular ore is the octahedral arseniate of copper.-In anatomy, the term is applied to a ganglion of the head situated on the external side of the optic nerve; and also to the papillæ situated at the posterior part of the tongue, which are from nine to fifteen in number, of the size

of a large mustard seed. Lenti'go (Lat.), a freckly eruption upon the skin.

Lentil (Fr.), a plant of the Vetch kind; a sort of pulse with orbicular seeds. Len'zinite, in mineralogy, a hydrated silicate of alumina, white and translucent, consisting of silica, alumina, and water: sp. gr. 1.8-2.10; Η = 1.5.

Leo (Lat.), in astronomy, the Lion; the fifth sign of the zodiac, consisting of fifty-nine stars.

Leonhardite, a mineral resembling laumonite.

Lep'adites (Gr. lepas a limpet), a family of Cirripeds (the Goose Barnacles), of which Lepas is a genus. Lepidodendron (Gr. lepis a scale, and dendron a tree), a genus of fossil plants found in coal formations. Lepido'ganoid (Gr.), in geology the name of a sub-order of fossilized ganoid fishes.

Lepidolep'ridæ (Gr. rough-scaled), a family of fishes, the Ribbons. Lep'idolite (Gr. lepis, and lithos a stone), a mineral of pinkish colour and granular texture.

Lepidop'tera (Gr. lepis, and pteron a wing), in entomology, an order of insects having four wings, as the Butterfly and Moth.

Lepiphyllum (Gr.), in geology, a fossil leaf which occurs in coal formations.

Leporidae (Lat. lepus a hare), in zoology, a family of rodent animals, as the Hare.

Lepra, or Lep'rosy (Lat.), a loathsome disease of the skin.

Lep'tides (Gr.), a sub-family of dipterous insects, of which Leptis is the genus.

Leptostom'inæ (Gr. slender-mouthed), a sub-division of the Cuculidæ, or Long-billed Cuckoos, of which the Leptostoma is the genus.

Leto, the name of one of the newlydiscovered planets, first observed by Luther in 1861.

Leucæ'mia (Gr.), in pathology, whiteness of blood.

Leuchtenber'gite, a mineral of a yellowish colour and pearly lustre. Its constituents are silica, alumina, magnesia, peroxide of iron, lime, and water: sp. gr. 2.97.

Leucine (Gr. leukos white), in chemistry, a white pulverulent substance obtained by sulphuric acid acting on muscular fibre.

Leucite (Gr. leukos), a white volcanic mineral, consisting of silica, alumina, potash, and oxide of iron: sp. gr. 2.48; H=5.5-6.0.

Leucocythæ'mia (Gr. leukos, kytos a cell, and haima blood), in pathology, a diseased state of the body, which is characterized by an excess of white particles in the blood. Leuco'ma (Gr.), a white opacity of the cornea of the eye.

Leu'cophane (Gr. whitish appearance), a mineral found in Norway imperfectly crystallized, of a pale greenish colour and vitreous lustre; its constituents being silica, glucina, lime, fluorine, sodium, protoxide of manganese, and potassium: sp. gr. 2.97; H=3.50-3.75

Leucophleg'macy (Gr.), a dropsical habit.

Leucopy'ria (Gr. leukos, and pyr fever), in pathology, hectic fever. Leucop'yrite (Gr.), arsenical pyrites. Leucorrhœ'a (Gr. leukos, and rheo to flow), in pathology, fluor albus, commonly known as the whites.

Leucothe'a, in astronomy, the name of one of the newly-discovered planets, first observed by Luther in 1855. Its mean distance from the sun is 276,960,000 miles, and its periodical revolution 4 years and 340 days. Leva'tor (Lat.), in anatomy, a muscle that lifts up some part, as the lip or the eyelid; the name also of a surgical instrument for raising up a depressed part, as of the skull. Of the Levator muscles, the principal are the Levator labii inferioris, a muscle of the mouth situated below the lips; -Levator labii superioris, a muscle of the mouth and lips that raises the upper lip towards the orbit, and a little outwards; - Levator oculi, the rectus superior oculi;-Levator palati, a muscle situated between the lower jaw and the os hyodes, laterally.-Levator palpebræ superioris, a proper muscle of the upper eyelid.-Levator scapulæ, a muscle situated on the posterior part of the neck;-Levator anguli oris, a muscle situated above the mouth, which draws the corner of it upwards, and makes that part of the cheek opposite to the chin prominent, as in smiling; - Levator ani, a muscle of the rectum, which rises from the os pubis, within the pelvis; - Levator ani parvus, the transverse muscle of the perinæum. Level, in surveying and the science of practical geometry, an instrument which shows the direction of a straight line parallel to the plane of the horizon. A spirit-level is a glass tube filled generally with spirit of wine, the bubble in which, when the tube is placed horizontally, occupies the upper part. The artillery footlevel and gunner's level-bender, the line and plummet of the common level, with a scale for showing the inclination of a straight line to the horizon. -Levelling is the art of determining the depressions or heights of points on the ground, with respect to a spheroidal surface coinciding nearly with that of the earth.-Levelling staves are instruments used with the spirit-level for supporting a mark, and showing, at the same time, its height above the ground.

Lever (Fr. levier, Ital. leva), in mechanics, a bar, or inflexible rod, for raising a great weight by turning on a fulcrum or prop; the second power in mechanical science. - Universal lever is a machine formed by the combination of the lever with the wheel and axis.-Lever boards are a set of boards to fasten so that they may be turned at any angle to admit