Mesompha'lion (Gr.), in anatomy, the middle navel.

Mesotho'rax (Gr.), the middle thorax or trunk of an insect.

Mes'otype (Gr.), a hydrated silicate of alumina and soda. Mesozoic (Gr. mesos and zoe, middle life), in geology, an epithet applied to the middle period of the earth's crust as relates to animal remains.

Mesto (Ital.), in music, a term signifying that a piece is to be played in the pathetic style.

Meta (Gr.), a prefix to compound words, sigrifying beyond.

Metabolians (Gr. metabole change), in entomology, a class of insects that undergoes a metamorphosis. Metacarpus (Gr. meta, and harpos the wrist), that part of the hand between the wrist and the fingers. Metagal'late, a salt formed from metagallic acid and a base.

Metagen'esis (Gr. meta, and gennao to reproduce), in zoology, the changes of form which the representative of a species undergoes in passing from an imperfect to a more perfect

state.

Metal (Fr. from Lat. metallum), an undecompounded body of peculiar lustre, insoluble in water, fusible by heat, and capable, in the state of an oxide, of uniting with acids, and forming with them metallic salts. Metals are distinguished, in different degrees, by malleability, ductility, fusibility, tenacity, elasticity, and crystalline texture. Gold, silver, iron, copper, mercury, lead, and tin were known to the ancients from the earliest periods. Gold and silver were called noble metals; the rest base metals. The following is a list of the metals, arranged according to the order of time when they were first discovered:

Silicium and Zirconium... 1824 Aluminium, Glucinium,

1828

and Yttrium
Thorium and Magnesium 1829

These metals are distinguished into different classes, which have been thus arranged by Hoblyn:-1. Metallic bases of the alkalies, viz., potassium, sodium, and lithium. The oxides are termed alkalies, and the metallic bases alkaline or alkaligenous metals.-2. Metallic bases of the alkaline earths, viz., barium, strontium, calcium, and magnesium, and their oxides are termed alkaline earths.-3. Metallic bases of the earths, viz., aluminium, zirconium, glucinium, silicium, yttrium, and thorium.-4. Metals yielding oxides, which are neutral salifiable bases, viz., gold, silver, mercury, copper, lead, iron, tin, platinum, palladium, nickel, cadmium, zinc, bismuth, antimony, cobait, and manganese.-5. Metals which are acidifiable by combination with oxygen, viz., tellurium, arsenic, chromium, molybdenum, tungsten, columbium, and selenium.-6. Metals magnetic, viz., iron, nickel, and cobalt. Metals are termed native when found in an uncombined form; mineralized, when combined with other bodies; compounds of two or more metals, except mercury, are called alloys, and possess the characteristic properties of pure metals; those of mercury with other metals are called amalgams. Metals are the best reflectors of caloric, and the worst radiators.(Gray, Ure, Hoblyn.)

Metalling, an engineering term for stone and other material applied to give firmness and solidity to roads and railways.

Metalloch'romy (Gr. chromos colour), art of colouring metals. Metallography (Gr.), a description of metals.

Metalloid, in chemistry, a non-metallic, inflammable body, as sulphur, phosphorus, &c.; applied also to the metallic bases of the fixed alkalies. Metallurgy (Gr.), the art of working metals, or separating them from their

1733

ores.

Metamorphic (Gr.), in geology, changeable, as applied to a class of stratified primary rocks. - Metamorphism is the state of being metamorphic.

Metaphysics (Gr. meta, and physis nature), the philosophy of mind, as distinguished from that of matter; a speculative science, which soars beyond the bounds of actual experience. The science has been divided into six parts-ontology, cosmology, anthropophosy, psychology, pneumatology, and metaphysical theology. Metastasis (Gr. meta, and stasis standing), the removal of the seat of a disease from one place to another. Metatar'sus (Gr.), the sole of the foot between the toes and the ankle.

Me'teor (Gr. meteora things in the air), any natural phenomenon in the atmosphere or clouds; a fiery or luminous body occasionally seen moving rapidly through the atmosphere.Meteors may be divided into classes according to their nature or origin. Thus winds, whirlwinds, &c., are aërial meteors; dews, fogs, rain, snow, and other depositions or disturbances of the water of the atmosphere, are called aqueous meteors. Many arise from the refraction or reflection of light from the aqueous particles suspended in the air; these are called luminous meteors-such are halo, mirage, rainbow, &c.; while those that present the appearance and phenomena of combustion are igneous meteors-such are falling stars, lightning, &c.-Meteorology is the science of the atmosphere, and its various phenomena.

Meteorite, or Meteor'olite (Gr. meteoros, and lithos a stone), a solid substance or body falling from the high regions of the atmosphere; a meteoric stone. Meteoros'copy (Gr. meteoros, and skopeo to view), that part of astronomy which treats of the difference of the remote heavenly bodies, their distances, &c.-Meteoroscope is an instrument for taking the magnitude and distances of the heavenly bodies. Methyl (Gr. methu wine, and yle material), in chemistry, a compound of carbon and hydrogen.

Meth'ylated Spirit (Gr. methu), spirit of wine 5 per cent. over proof, mixed with wood naphtha, or methylic spirit. Methylene (Gr.), in chemistry, a highly volatile and inflammable liquid compound of carbon and hydrogen. Meťoche (Gr.), in architecture, the space between two dentils.

Met'ope (Gr.), in architecture, a square space between triglyphs in the frieze of the Doric order.

Metralgia (Gr. meter the womb, and algos), pain in the womb. Metrans'trophe (Gr.), inversion of the womb.

Metri'tis (Gr.), inflammation of the womb.

Met'rocele (Gr.), hernia of the womb. Metrology (Gr. metron measure, and logos discourse), a treatise on weights and measures.

Metronome (Gr.), in music, an instrument for determining the movements of musical compositions. Metronomy (Gr. metron, and nomos law), the measuring of time by an instrument.

Metrorrhagia (Gr. meter, and segnymi to burst forth), hæmorrhage of the womb.

Metrotomy (Gr.), incision of the womb. Mezza-voce (Ital.), in music, an expression denoting that the movement is to be sung or played with moderate strength.

Mezzo-relievo (Ital.), middle or demirelief.

Mez'zotint, Mezzotin'to (Ital.), a kind of engraving on copper, resembling drawings in Indian ink.

Miasm, Mias'ma, pl. Mias'mata, a noxious particle, substance, or exhalation floating in the air.

Mica (Gr. shining), a mineral generally found in thin transparent laminæ; one of the ingredients of granite, gneiss, and mica slate. Mica Schist, in mineralogy, one of the lowest stratified rocks, composed of quartz and mica. Michaelite, in mineralogy, a variety of opal.

Micro- (Gr. mikros), a prefix to compound words, signifying smallness. Microcosm (Gr. mikros, and kosmos world), the little world; man considered as an epitome of the macrocosm, or the great world. Microg'raphy (Gr.), the description of such objects as are too minute to be seen without the help of a micro

scope.

Microlite (Gr. a minute stone), a mineral having very small crystals. Micrology (Gr.), a treatise on microscopic animals and plants. Microm'eter (Gr.), an instrument applied to telescopes and microscopes for measuring very small distances. Microphon'ics (Gr.), the science of magnifying low sounds. Mi'croscope (Gr. mikros, and skopeo to view), an optical instrument which enables us to examine objects too minute to be seen by the naked eye. Micros'mic Salt, in chemistry, a triple salt of soda, ammonia, and phosphoric acid.

Microscopy (Gr.), the art by which small objects are made to appearlarge. Micturition (Lat.), the voiding of urine. Mid'dletonite, a mineral found between layers of coal.

Midrib, in botany, the principal vein of

Milk (Sax. melce), in zoology, a fluid secreted in the breasts or udders of mammiferous animals, and with which such animals feed their young. -In botany, it is the emulsion or juice of plants. - Woman's milk contains butter or fatty matter, 4.5 per cent.; sugar of milk, 3.5.-Cow's milk contains cream, 46; butter or fatty matter, 2.68; caseum, 8.95; sugar of milk, 3.60.

Milky Way, in astronomy, a broad and irregular starry zone or galaxy that surrounds the heavens; a great luminous band that stretches from horizon to horizon, and which, when traced with diligence and mapped down, is found to form a zone completely surrounding the whole sphere, almost in a great circle. This remarkable belt has maintained, from the earliest ages, the same relative position among the stars; and when examined through telescopes, is found to consist entirely of stars, scattered by millions, like glittering dust on the face of the general heavens.

Mill (Sax.), an engine or machine for grinding grain, fruit, or other substances, whose action depends chiefly on circular motion; as, a bark-mill, cotton mill, flour-mill, oil - mill, saw-mill, &c.

Mil'legram (Fr.), a thousandth part of a gramme in French measure. Mil'leped (Lat.), an insect having a great many feet; the Wood-louse. Millepor'idæ (Lat. mille a thousand, and Gr. poros a pore), the name of an extensive family of stone - making Polypes.

Mil'leporite, in geology, fossil mille

Mimo'seæ (Gr. mimos a mimic), in botany, an order of leguminous plants, of which the Mimosa, or Sensitiveplant, is the type.

a

Mine (Fr.), a subterraneous work or excavation for obtaining metals, metallic ores, or other mineral substances; also, an excavation for lodging gunpowder in order to blow up something above. Military mines are excavations made in the rampart of fortress, or under ground, in order to contain gunpowder, by which, on being exploded, the rampart may be breached, or any works of the enemy above the mine, or near it, may be destroyed. Mineral (Fr. from Low Lat.), a body destitute of organization, and which naturally exists within the earth or on its surface; a term including all inorganic substances. Mineral, as an epithet, has various applications. -Mineral kingdom is a term applied to the third grand division of natural objects, embracing all inorganic substances whatever. - Mineral acids comprehend the nitric, sulphuric, hydrochloric, chromic, and numerous other acids. - Mineral salts are salts found native, being formed by the mineral acids with bases. -Mineral waters are waters impregnated with mineral substances. - Mineral caoutchouc is a variety of bitumen, intermediate between the harder and softer kinds. - Mineral charcoal is a fibrous variety of non-bituminous mineral coal.-Mineral green is carbonate of copper.-Mineral adipocere is a fatty bituminous substance which occurs in the argillaceous iron ore of Merthyr, in Wales. Mineralogy (mineral, and Gr. logos a discourse), the science which teaches the proportions, composition, and relations of mineral bodies, and the art of distinguishing and describing them.

Minim (Lat.), in music, half a semibreve, and double that of a crotchet. Min'ium (Lat.), in painting, red oxide of lead, a compound substance procured by exposing the protoxide of lead to the long-continued action of heat and air, by which it acquires more oxygen, and becomes of a fine red colour.

Min'uend (Lat.), in arithmetic, the number from which another number is to be subtracted.

Minus (Lat.), in algebra, a term signi

fying less; noting the sign of subtraction thus (-); as, 10-64.

Minus'cule (Lat.), a small or minute sort of character used in MSS. in the middle ages.

Miocene (Gr. meion less, and kainos recent), in geology, relating to the second division of the tertiary epoch. The miocene strata contain an admixture of the extinct genera of lacustrine Mammalia of the eocene period, with the earliest forms of genera which exist at the present day. Mirab'ilite, the efflorescence on the soil among salt springs.

Mirage (Fr.), in meteorology, an optical illusion, presenting an image of water in sandy deserts, or of a village in a desert, as if built on a lake.

Miscarriage, in pathology, the expulsion of the fœtus from the uterus within six weeks after conception. If it occurs before six months, it is called abortion; and if during any part of the three months before the completion of the natural term, premature labour.

Mistu'ra (Lat.), in pharmacy, a fluid composed of two or more ingredients, mostly contracted in prescriptions; thus, f. mis. means, let a mixture be made.

Mithridate, in medicine, a confection. -In botany, common mustard. Mitral (Gr. mitra a mitre), in anatomy, applied to the valves of the left ventricle of the heart.

Mitra'næ, in conchology, a sub-family of Volutidæ, or Volutes. Mnemon'ics, Mnemotech'ny (Gr. mneme memory), the science of improving the memory by artificial means. Mnemosyne, the name of one of the newly-discovered planets, first observed by Luther in 1859.

Mocha Stone, in mineralogy, the moss

agate.

Modera'to (Ital.), in music, noting a moderate time, neither quick nor slow.

Modil'lion (Fr.), in architecture, an ornament, sometimes square on its profile, and sometimes scroll-shaped, placed under the cornice of a building; a console or bracket.

Module (Fr. from Lat. modulus), in architecture, a measure taken for regulating the proportions of an order, or the dispositions of the whole building; the diameter or semi-diameter of the column at the bottom of the shaft has usually been selected by architects as their module. Mohsite (from Mohs, the celebrated mineralogist), in mineralogy, the crystallized titanite of iron.

Moineau (Fr.), a small, flat bastion

raised in front of an intended fortification.

Mola'res (Lat.), in anatomy, a term applied to the double teeth, the grinders. -Molares glandula are two salivary glands, situated on each side of the mouth, between the masseter and buccinator muscles, the excretory ducts of which open near the last dens molaris.

Mole (Lat.), in engineering, a massive work of masonry or stones, placed in the sea by means of coffer-dams, extended either in a right line or in an arc of a circle, before a port, which it serves to close, and to defend the vessels therein from the impetuosity of the waves. In pathology, a mass of fleshy matter growing in the uterus.

Molecule (Lat.), a very minute particle of matter; an atom; a corpuscle.-Integral molecule, in mineralogy, is the last particle into which the nucleus of a crystal can be mechanically divided. Mollusc, pl. Mollusca (Lat. mollis soft), a molluscous animal, with a soft, invertebrated body and no internal skeleton, but furnished with respiratory and circulating organs, and a nervous system. The Mollusca constitute an important division of the animal kingdom, and are divided into six classes-the Cephalopoda, Pteropoda, Acephala, Brachiopoda, and Cirrhipoda, or Cirropods. Molto (Ital. from Lat. multum), in music, a word generally used in combination by way of augmentation; as, molto allegro, very quick; molto adagio, very slow, &c.

Molybdate (Gr. molybdaina lead), a salt composed of molybdic acid and a base.-Molybdate of lead is a mineral which occurs crystallized and massive; it consists of oxide of lead, molybdic acid, and oxide of iron. Molybde'na, Molyb'den (Gr.), a mineral ore, which is a common sulphate of molybdenum.

Molybdenite (Gr.), a mineral containing molybdenum. Molybdenum (Gr.), a sort of brittle metal, mineralized by sulphur. Molyb'dic Acid, in chemistry, an acid formed by oxidizing the binoxide of molybdenum with nitric acid, and forming a fine white powder. Molyb'do-sulphuret, a combination of molybdenum with sulphur. Momentum (Lat.), in mechanical science, the force possessed by matter in motion, or the quantity of motion in a moving body. Mon-, or Mono- (Gr. monos), a prefix in compound words, signifying single or only one.

Monad (Gr. monos), an ultimate atom; a primary constituent of matter. Mon'adelph (Gr. a single brother), in botany, a plant whose stamens are united into one parcel by filaments. -In the Linnæan system, Monadelphia is a class of plants consisting of those which have hermaphrodite flowers, and have the filaments cohering in a tube.

Monadel'phon (Gr.), in botany, a stamen of which the filaments are combined into a single mass.

Monan'dria (Gr. monos, and aner, andros a male or stamen), in botany, the first class of plants in the Linnæan system, having only one stamen. -Monandrian, belonging to the class Monandria.

Mon'azite, a reddish-brown mineral. Mongolian, in ethnology, a term applied to a class of mankind who have the Mongols and the Chinese as the type. Monkey Wrench, in mechanical science, a spanner with a movable jaw. Monobas'ic (Gr.), in chemistry, having only a single atom of base.

Mon'ochord (Gr.), in music, an instrument of one string, used for the purpose of ascertaining and demonstrating the relative proportions of musical sounds.

Monochrome (Gr. monos, and chroma colour), a painting executed in a single colour.

Monocle (Fr.), a reading-glass for one eye.

Monocli'nate (Gr.), in mineralogy, a term applied to crystals in which one of the axes is obliquely inclined. Monocotyle'don (Gr.), a plant having only one seed-lobe; an Endogen. Mon'odelph (Gr. one womb), in zoology, a Mammal which brings forth its young in so mature a state as not to require the protection of a pouch.

Monce'cian (Gr. monos, and oikos dwelling), a class of plants which have the stamens and pistils in separate flowers of the same plant.

Mon'ogam (Gr. monos, and gamos marriage), in botany, a plant that has a simple flower, though the anthers are united.

Monogram (Gr. single letter), one character or cipher in writing; an abbreviation of a name by means of a cipher or figure composed of an intertexture of letters.

Mon'ogyn (Gr. one female), a plant having only one style or stigma. Monogynia is the name of the first order in each of the first thirteen classes in the botanical system of Linnæus.

Mon'olith (Gr. a single stone), an obelisk or monument formed of a single

Monoma'nia (Gr.), in pathology, insanity

upon one particular subject.

Monome (Fr.), in algebra, an expression composed of a single term, or a series of factors, all of which are single terms.

Monome'rans (Gr. monos, and meros limb), in entomology, a section of coleopterous insects, including those in which the tarsi were supposed to be formed by a single joint. Monop'teron (Gr.one-winged), a temple or edifice consisting of a circular colonnade supporting a dome. -Monopteral, having only a single wing. Monotremes (Gr. monos, and trema a hole), in zoology, a family of edentate Mammalia, with one external aperture for the passage of the semen, urine, and other excrements. It consists of two genera, the Echidna and Ornithorhynchus.

Monotriglyph (Gr.), in architecture, such an intercolumniation in the Doric order as brings only one triglyph over it.

Monotropa'ceæ (Gr. monos, and trepo to turn), in botany, a nat. order of Exogens, the Rape Firs, of which Monotropa is the genus.

Monsoon, in physicology, a modification of the trade winds in the Eastern

seas.

Month (Sax. monath, from mona the moon), a division of time regulated by the course of the moon and the sun. The lunar month is the time from one new moon to another, or 29 days, 12 hours, 44 min., 3 sec. - A solar month is the time in which the sun runs through one entire sign of the zodiac, the mean quantity of which is 30 days, 10 hours, 29 min., 5 sec. Montmartrite, in mineralogy, a compound of the sulphate and carbonate of lime, found at Montmartre, near Paris.

Moon (Sax. mona), in astronomy, one of the heavenly bodies; the satellite of the earth, round which she revolves as a centre. Her sidereal revolution is in 27 days, 7 hours, 43 min.; her synodical revolution is 29 days, 12 hours, 44 min., 3 sec.; her mean distance from the earth, about 237,000 miles. The rotation on her axis is uniform, and is performed in the same time as her revolution in her orbit, whence she always presents nearly the same face to the earth.-Halfmoon, in fortification, is an outwork resembling a crescent in form. Moonstone, in mineralogy, a variety of adularia, or resplendent felspar. Moorstone, in mineralogy, a whitish kind of granite, existing in Cornwall and other parts of England, found