Red hartshorn, Lavender drops, Spiritus lavendulæ compositus;Salt of hartshorn, a solid carbonate of ammonia.

Harvest Moon, the lunation in the season of harvest, which occurs about the time of the autumnal equinox.

Hatchetine, (from Hatchet, the eminent chemist), a bituminous mineral or mountain-tallow, found at Merthyr Tydvil, in S. Wales.

Hatching, the maturing of fecundated eggs by natural or artificial heat, so as to produce the young birds. In drawing and engraving, hatching is the making of lines with a pen, pencil, or graver, the intersecting of such lines with others is termed cross or counter-hatching.-In heraldry, hatching is much used to denote the several colours of a shield.

Hau'rient (Lat. haurio to drink), in heraldry, an epithet applied to fishes when represented in a perpendicular position, as if sucking in the air. Haus'manite (Germ.), a manganesian mineral found in the Hartz, which occurs massive and granular; its constituents are red oxide of manganese, oxygen, water, baryta, and silica: sp. gr. 4.8; Η = 5.0-5.5.

Haustella'ta (Lat. haustellum a sucker), in entomology, one of a numerous class of insects which have the oral apparatus adapted for suction. Haustellum, the suctorial organ of the Haustellata.

Hauyne, (from Hauy, the distinguished French mineralogist), a blue mineral found in granular or spherical masses. It is harder than quartz, and consists of potash, silica, alumina, lime, oxide of iron, sulphuric acid, and water: sp. gr. 2.68-3.0.

Haver'sian Canals, in anatomy, small longitudinal canals in the substance of bones, so called from the name of Dr. Havers, who first discovered them.

Hawthorn (Sax. haw the fruit, and thorn), the English name of several species of the genus Cratægus.-C. oxycanthus is the well-known hedgeplant of Great Britain; order Po

maceæ.

Hay'denite, a mineral resembling chabasite, discovered by Dr. Hayden. Hay'essine, in chemistry, the borate of lime, used in the manufacture of glass, and so called from its discoverer, Mr. Hayes.

Hazel (Sax.), the popular name of plants of the genus Corylus.-C.avellana produces the common hazel-nut. Heart (Sax. heort), in anatomy, the most important organ of the viscera of mammiferous and other animals. It

is the muscle which is the seat of life in the animal system. In man, it is situated in the thorax, on the anterior part of the diaphragm. Internally it is divided into the two ventricles, right and left, which are separated from each other by a fleshy septum, called the septum cordis. The cavities adhering to the base are, from their resemblance in form, called the auricles. Each ventricle has two orifices-the one auricular, through which the blood enters; the other arterious, through which it passes out. The vessels of the heart are distinguished into common and proper. The common are the aorta, arising from the left ventricle; the pulmonary artery, from the right ventricle; the four pulmonary veins, which terminate in the left auricle; the two venæ cavæ, which empty themselves into the right auricle. The proper vessels are the coronary arteries, which arise from the aorta, and are distributed on the heart, and the coronary veins. Heat (Sax.), in physiology, the sensation caused by a hot body, or the cause of that sensation. In chemistry, the supposed matter or cause of heat, termed caloric, which, if material, is an imponderable subtile fluid, the particles of which repel each other, and are attracted by all other substances, either by direct contact or radiation.-Animal heat is the heat consequent on respiration and digestion in the bodies of animals, produced in the system of each by the oxygen of the atmosphere combining with the carbon of the blood, and forming carbonic acid gas.-In mechanics, the term is applied to that degree of heat which is required for iron-work, namely, the blood-red heat, the smallest degree; the flame, or white heat, the second degree; and the sparkling, or welding heat, which is the strongest degree.

Hebe, in astronomy, the name of one of the newly-discovered planets, first observed by Hencke in 1847. Its mean distance from the sun is 231,350,000 miles; and the time of its periodical revolution is 3 years and 284 days.In natural history, the word hebe frequently occurs in the definition of species, and signifies pubescence; as, hebeanthus, having pubescent or downy flowers; hebecarpus, having downy seeds; hebecladus, having downy branches; hebegynus, having the ovary pubescent; hebepetalus, having downy petals.

Hectare, a French measure, consisting of 10,000 square mètres, or 11960 33 English square yards.

Hectic (Gr. hexis habit), in pathology, a form of fever arising from local irritation in a feeble constitution.

Hec'togramme (Fr.), a French weight of 100 grammes = 3.2 ounces troy.

Hec'tolitre (Fr.), a French measure of capacity, containing 100 litres = 22 English imperial gallons.

Hectomètre (Fr.), a French linear measure of 100 mètres = 328 English feet. Hedenber'gite, a species of mineral, of a greenish-black colour, with a shining lustre. Its constituents are-silica, lime, magnesia, and protoxide of iron: sp. gr. 3 154; Η = 3.5.

He'dyphane (Gr. hedys pleasing, and phaneo to appear), a white or greyish mineral, consisting of oxide of lead and lime.

Hel'enine, in mineralogy, a substance obtained in white crystals from the plant Inula helenium. Formula, C14 H12012.

He'liac, or Heli'acal (Gr. helios), relating to the sun. In astronomy, a star is said to rise heliacally when, after being in conjunction with the sun, it rises so as to be visible.

Heliantheæ (Gr. helios the sun, and anthos a flower), in botany, a suborder of the Compositæ, of which Helianthus, or Sunflower, is the type. Helianthoi'da (Gr.), an order of Polypes resembling a sunflower. Helicoid (Gr.), in geometry, a parabolic spiral or curve line.

Helicom'etry (Gr.), in geometry, the art of measuring spiral lines on a plane. Heliocentric (Gr.), in astronomy, relating to the sun's centre.-Heliocentric longitude is the angle formed at the sun's centre by the projection of the radius vector of a planet on the ecliptic, with a line drawn from the sun's centre to the first point of Aries. -Dr. Henry.

Helioch'romy (Gr.), the process by which photographic pictures in their natural colours are obtained.

Heliography (Gr.), a description of the

sun.

Heliom'eter (Gr.), a micrometer for measuring the diameters of the sun, moon, and planets.

He'lioscope (Gr.), a telescope for making observations of the sun without dazzling the eyes.

Heliostat (Gr.), in optics, an instrument used to fix the position of the solar rays.

He'liotrope (Gr.), in mineralogy, a deep green, siliceous mineral, with red spots. In astronomy, an instrument to reflect light.--In botany, a plant that turns towards the sun; the Turn

sole.

Helispheric (Gr.), winding spirally

round the pole of the sphere; noting the rhumb line in navigation.

Helix, pl. Hel'ices (Gr.), a spiral line; the smaller scroll or volute in a Corinthian capital.

Helminthachor'ton (Gr. helmins a worm, and chorton food), in botany, Corsican wormwood, celebrated for its vermifuge properties.

Helmin'thia, Helmin'thagogue (Gr.), a medicine for expelling worms. Helmin'tholite (Gr.), fossil remains of

worms.

Helminthology (Gr.), the natural history of worms.

Helminthop'yra (Gr.), worm disease. Helminthos'tachys (Gr.), a brownyellow flowering plant; order Ophioglossaceæ.

Helop'ide (Gr. Helops, one of the genera), a family of coleopterous insects. Helo'sis (Gr. heilio to turn), an eversion of the eyelids; a spasmodic distortion from convulsion of the muscles of the eye.

Helvin, a crystallized mineral, of which the primary form is a cube. Its constituents are-silica, glucine, alumina, glucina, protoxide of manganese, protoxide of iron, and sulphuret of manganese: sp. gr. 0166; H = 6.0-6.5. He'matherms (Gr. haima blood, and therme heat), a name given to animals possessed of warm blood.

Hem'atine (Gr.), the colouring principle of logwood.

Hem'atite (Gr.), the blood-stone; a kind of ironstone; a native oxide of iron. Hematology (Gr.), science of the blood. Hemato'sine (Gr.), one of the proximate principles of the blood. Hemeralo'pia (Gr. hemera a day, and ops the eye), in pathology, a disease which prevents distinct vision in broad daylight.

Hemerapa'thia (Gr. hemera, and pathos disease), in pathology, certain states of disease or affections which are observed only by day, or which last only one day. Hemerobi'idæ (Gr. a day's life), in entomology, a family of neuropterous insects, the Hemerobiars, of which the Hemerobius is the type. Hemerocal'leæ (Gr. hemera, and kalos beautiful), in botany, a tribe of the Liliaceæ, or Day-lilies, assimilating to the Tulips.

Hemi, a Greek prefix signifying half, equivalent to demi and semi; frequently used as a prefix in composi

used to denote vaults of the cradle form, and arches or sweeps of vaults constituting a semicircle.

Hemihe'dral (Gr.), in mineralogy, a term applied to a crystal with half of the similar edges or angles similarly replaced.

Hemiolog'amous (Gr.), in botany, applied to Grasses having some florets neuter and some hermaphrodite.

Hemio'pia (Gr. hemi, and ops the eye), a disease obscuring part of an object from sight.

Hem'iplegy (Gr. hemi, and plesso to strike), a paralysis of one side of the body.

Hemiprismatic (Gr.), in mineralogy, applied to such combinations of crystals as only show half of the faces.

Hemip'tera (Gr. hemi, and pteron a wing), a class of insects having the upper wings half-crustaceous and half-membranous.

Hem'isphere (Gr.), a map or projection of half the terrestrial globe. In astronomy, one half of the mundane sphere. The equator divides the sphere into two equal parts; that on the north is called the northern hemisphere, the other the southern. So the horizon divides the sphere into the upper and lower hemispheres.

Hem'itone (Gr.), in music, a semitone or half-note.

Hemi'trope (Gr.), in mineralogy, having two parts.

Hemlock, a poisonous biennial plant. -Hemlock Spruce, the Abies Cana

densis.

Hem'orrhage (Gr. haima, and rhegnymı to burst), a flux of blood from the bursting of a vessel.

Hem'orrhoids (Gr. haima, and rheo to flow), in pathology, the piles.

Hemp (Sax. hænep), in botany, a plant of whose fibres ropes and coarse linen are made. -Bengal hemp is the coarse fibre of the plant Crotalaria juncea. Hemp Agrimony is the plant Eupatorium cannabinum.

Hendec'agon (Gr.), in geometry, a figure of eleven angles. Henna, a plant whose leaves are used by Oriental women to stain their nails. Hepar (Gr.), the liver.-Hepar sulphuris, liver of sulphur; a combination of sulphur with an alkali. Hepatal'gia (Gr.), pain of the liver. Hepatic (Gr. hepar), in pathology and anatomy, an epithet applying to the liver; as, Hepatic artery and hepatic duct, situated between the lobes of the liver;-Hepatic glands, those glands which receive the lymphatic glands of the liver;-Hepatic plexus is connected with the hepatic vessels and the vena portæ;-Hepatic

cinnabar, a dark-coloured steel-grey variety of cinnabar, the Mercure sulphur of Hauy;-Hepatic pyrites, or hepatic sulphuret of iron, a variety of prismatic iron pyrites of a yellow colour;-Hepatic flux, a form of dysentery, accompanied with copious discharges of bilious matter.

Hepaticæ (Gr. hepar), in botany, one of the groups of Dr. Lindley's Muscal alliance; comprising the orders Ricciaceæ, Marchantiaceæ, Jungermanniaceæ, and Equisitaceæ. Hepatirrhœ'a (Gr. hepar, and rheo to flow), in pathology, an intestinal flux. Hepatisa'tion (Lat.), in pathology, conversion of the lungs into a liver-like substance.

Hep'atite (Gr.), in mineralogy, a variety of heavy-spar, distinguished by its emitting a fetid smell when rubbed. Hepatitis (Gr.), inflammation of the liver.

He'pato- (Gr.), in anatomy, a prefix to numerous words, signifying connection with the liver.

Hep'atocele (Gr.), hernia of the liver. Hepatogas'tric (Gr.), belonging to the liver and stomach.

Hepatog'raphy (Gr. hepar, and graphe to describe), in anatomy, a description of the liver.

Hepatology (Gr.), a treatise on the liver. Hepial'idæ, a family of lepidopterous insects, of the section Nocturna, of which the Hepialus, or Ghost-moth, is the type.

Heptagon (Gr. hepta seven, and gonia an angle), in geometry, a figure of seven angles. In fortification, a place with seven defensive bastions. -Heptahedron, a solid figure with seven sides.

Heptagyn'ia (Gr. hepta, and gyne a female), in botany, an order in the Linnæan system, which comprehends plants whose flowers have seven pistils.-Heptandrian, having seven

stamens.

Heptahexahe'dral, in mineralogy, presenting seven ranges of faces, one above another, each range containing six faces.

Heptas'tichous (Gr. hepta, and stichos, a row), in botany, applied to the arrangement of leaves in seven spiral rows, the eighth leaf in the series being placed above the first.

Heraldry, the science of conventional distinctions impressed on shields, banners, &c.

Herbivora (Lat. herba, and voro to eat), in zoology, animals that feed on grass; a name applied by Cuvier to a family of the Cetacea, including the Lamantins, the Dugongs, and the Stellerus.

Herboriza'tion, botanical researches; the appearance of plants in fossils. Hercules, in astronomy, one of the constellations of the northern hemisphere, situated between Draco, Bootes, Lyra, and Ophiuchus.

Her'derite, in mineralogy, a variety of fluor-spar, found in the form of a rhombic prism.

Her'ison (Fr.), in fortification, a beam armed with iron spikes, and used as a barrier.

Hermaphrodite (Gr. hermes, and Aphrodite Venus), partaking of both male and female natures in the same individual.

Hermeneutics (Gr.), the science of interpreting the Scriptures or other works in the learned languages.

Hermetic, Hermetical, chemical; completely closing. When a vessel is perfectly closed by fusing its extremity or mouth, it is said to be hermetically sealed.

Hernia (Lat.), a rupture; a tumour arising from the protrusion of a part of the intestines.-Herniotomy, the operation for hernia.

Herpes (Gr.), a cutaneous eruption or disease.

Herpetology (Gr.), that branch of natural history which treats of reptiles. Her'rerite, a translucent mineral, consisting of carbonic acid, peroxide of nickel, and tellurium.

Herschel, in astronomy, the planet Georgium Sidus, so called in honour of its discoverer, Sir W. Herschel. white translucent

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Her'schelite, mineral, which occurs in six-sided prisms, and consists of potash, silica, and alumina: sp. gr. 211; H = 4.5. Herse (Fr.), in fortification, a portcullis in the form of a harrow, set with iron spikes.

Her'sillon, in fortification and the military science, a plank or beam whose sides are set with spikes or nails, to incommode and retard the march of an enemy.

Hespe'ria, the name of one of the newlydiscovered planets, first observed in 1861.

Hesperide (Gr. hesperos evening), a family of lepidopterous insects (Hesperian Butterflies), of which Hesperia is the type; tribe Nocturidæ.

Hes'tia, the name of one of the newlydiscovered planets, first observed by Goldschmidt in 1857.

Hetero- (Gr.). (See Heteros.) Heterocercal (Gr. heteros irregular, and kerkos a tail), in ichthyology, a term applied to fishes in which the tail or caudal fin is unsymmetrical.

Heterogan'gliate (Gr. heteros different, and ganglion a knot of nerves), in

anatomy, having the nervous ganglia scattered unsystematically; more especially applied to the invertebrate molluscous animals.

Heterog'ena (Gr. heteros, and gyne a female), in entomology, a family of hymenopterous insects. Heterogen'esis (Gr. heteros, and genos kind), the production of a different kind or species in the animal or vegetable kingdom.

Heterom'era (Gr.), a section of coleopterous insects, consisting of four groups the Melasoma, Taxicornes, Stenelytra, and Trachelides.

Heterop'athy (Gr.), the practice of attempting to remove one disease by inducing a different one; the opposite of homœopathy.

Het'eropod (Gr.), an order of Gasteropods.

Heteropode (Gr.), an animal with finny feet.

Heterop'tics (Gr.), false optics. Heteros, a Greek word used as a prefix in many words, usually signifying otherwise, different in kind, not regular.

Heteros'cian (Gr. heteros, and skia shadow), having the shadow at noon always one way.

Heteroťamous (Gr.), in mineralogy, having a different cleavage. Heterozite, a mineral containing phosphoric acid and iron. Heu'landite, in mineralogy, a hemiprismatic Zeolite of various colours; its constituents are silica, alumina, and potash: sp. gr. 2'20; H=3.5-4.0. Hexagon (Gr. hex six, and gonia an angle), in geometry, a figure of six sides and six angles.

Hexagyn'ia (Gr. hex, and gyne, a female), a Linnæan order of plants having six pistils.

Hexahedron (Gr.), in geometry, a body of six sides; a cube. Hexan'dria (Gr.), the sixth class in the botanical system of Linnæus, including such plants as have six stamens.-Hexandrous, having six

stamens.

Hex'apod (Gr.), having six feet. Hex'astyle (Gr.), in architecture, a building having six columns in the portico.

Hexoctahedron (Gr.), a solid containing under forty-eight equal triangular faces.

Hibernate (Lat. hibernus wintry), to pass the winter in a torpid state, as some animals do.

Hidrotics (Gr.), medicines which produce perspiration. Hieroglyphics (Gr. hieros sacred, and glyphe carving), picture-writing, consisting of figures of animals, plants,

&c., as found sculptured or painted on Egyptian obelisks, temples, &c.Hierography, sacred writing. -Hierology, a treatise on sacred things.Hierophant, an interpreter of hieroglyphics, or sacred things.

High-pressure Engine, a steam-engine in which the steam is not condensed, but admitted into the cylinder at a very high temperature.

Hilum (Lat.), in pathology, a small blackish tumour formed by protrusion of the iris through a breach of the cornea. In botany, the mark on the seed when separated from the placenta.

Hippocampus (Gr.), in anatomy, a term applied to two productions of medullary substance in the lateral ventricle of the brain.

Hippocasta'neæ (Gr.horse-chestnuts), in botany, a tribe of the order Sapin

daceæ.

Hippocratea'ceæ, in botany, an order of plants consisting of arborescent or climbing trees, of which Hippocratea, so called from Hippocrates, is the type. Hip'polith (Gr. hippos a horse, and lithos a stone), a stone found in the intestines or stomach of the horse. Hip'pomane (Gr.), an excrescence on the forehead of a foal. Hippopathology (Gr.), pathology of the horse; treatise on veterinary medicine.

Hipposteology (Gr. hippos, and osteologia), a treatise on the anatomy of the horse.

Hippu'ric (Gr. hippos, and ourion urine), relating to the urine of horses.-Hippuric acid is a compound obtained from the urine of the horse when mixed with muriatic acid. Hip'purites (Gr. hippos, and oura a tail), in fossilology, a genus of plants in the chalk formation representing a horse's tail.

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Hippus (Gr.), in pathology, an alternate dilatation and constriction of the pupil of the eye, resulting from spasmodic affection of the iris. Hirsutus, or Hirtus (Lat. hairy), a term of frequent occurrence in the definition of species in natural history, signifying hairy, or prickly; as, Hirticaudis, hairy-tailed, or having the extremity of the wing-covers thickly set with hairs; hirticollis, hairynecked; hirticornis, having hairy antennæ; hirtiflorus, having hairy flowers; hirtipes, hairy-footed.

Hirudin'ide (Lat. hirudo a leech), a family of apodous Annelids, of which the Hirudo is the type and

tribe, of which the Hirundo, or Swallow, is the type.

Hisin'gerite, a black mineral, consisting of protoxide of iron, silica, alumina, oxide of manganese, and water: sp. gr. 3.04.

His'pidæ (Lat. hispidus bristly), a family of coleopterous insects, of which Hispa is the type; tribe Monili

cornes.

Histeride (Lat.), a family of coleopterous insects, of which Hister is the type; tribe Lamellicornes. Histog'eny (Gr. histos a tissue, and gennao to produce), in anatomy, the formation of organic tissues; from which we form the words-Histography, a description of the organic tissues; Histology, doctrine of the organic tissues; and Histonomy, the laws of organic tissues. Historiography (Gr. historia, and grapho to write), the art or science of writing history.

His'tory (Gr. historia). (See Natural History.)

Hol'etra (Gr. holos whole, and etron the abdomen), an order of Arachnides, or Spiders, in which the abdomen is closely joined to the thorax. Ho'libut, the flat fish Pleuronectes hyppoglossus, which sometimes weighs from three to four hundred pounds. Hollow Square, in military science, a body of infantry drawn up with an empty space in the middle for the colours, drums, and baggage, and facing the enemy in every direction. Holmite, in mineralogy, a variety of the carbonate of lime, consisting of lime, carbonic acid, oxide of iron, silica, alumina, and water.

Holohe'dral (Gr. holos whole, and hedron a side), in mineralogy, a term applied to a crystal with all the similar edges or angles similarly replaced. Holom'eter (Gr.), a mathematical instrument for taking measures. Holophan'erous (Gr.), an epithet applied to the metamorphosis of insects when complete.

Homalin'ese (Gr. homalos regular), in botany, a nat. order of exogenous plants, consisting of trees or shrubs, of which the Homalium is the type. Homiletics (Gr. social), the science which teaches the principles of adapting the discourses of the pulpit to the spiritual benefit of the hearers. Homo, in zoology, the Lat. for man, who constitutes the class and only genus and species of the order Bi