ulation, 6000. It contains a citadel, a Catholic gymnasium, a Carthusian monastery, and some good houses, but is generally ill-built.-Population of the circle, 135,567; houses, 24,298; families, 33,578; square miles, 1260. It is generally hilly, but tolerably fertile. In the neighborhood of this town, the armistice between the French and Austrians was concluded July 12, 1809, which was followed by the peace of Vienna. (q. v.)

ZOBEIDE, or Zebd-el-KhewaTIN (the flower of women), was the cousin and wife of the celebrated caliph Haroun al Rashid. (q. v.) History records her piety and generosity, and the Persian writers speak of her as the founder of Tauris, one of the chief cities of Persia: but she performs a more important part in the Arabian Nights, in which she is a more conspicuous character than in history. She died in 831, after having survived her illustrious husband twenty years.

ZOBTENBERG; a mountain in Silesia, about eighteen miles from Breslau, near the small town of Zobten, 2318 feet above the level of the sea, with a fine extensive view from the top. According to Büsching, the ancient Asciburg, or Asen castle (Asgard), stood here, corresponding to the mons Asciburgius of Ptolemy. The mountain is of a primary character. A block of from 7000 to 8000 cwt. was taken from this mountain, which, according to the wish of marshal Blücher, is to cover his tomb in the shape of a cube.

ZODIAC (from the Greek Zodia, animals, because the constellations composing it are represented under the figures of animals), in astronomy; an imaginary ring or broad circle in the heavens, in the form of a belt or girdle, within which the planets all make their revolutions. In the middle of it runs the ecliptic, or path of the sun in his annual course; and its breadth, comprehending the deviations or latitudes of the earlier known planets, is, by some authors, accounted sixteen, some eighteen, and others twenty degrees. The zodiac, cutting the equator obliquely, makes with it the same angle as the ecliptic, which is its middle line; which angle, continually varying, is now nearly equal to 23° 28', which is called the obliquity of the ecliptic, and constantly varies between certain limits which it can never exceed. (See Ecliptic.) The zodiac is divided into twelve equal parts, of thirty degrees each, called the signs of the zodiac, being so named from the constellations which anciently occupied them. But the stars having a motion from west to east, those

constellations do not now correspond to their proper signs; from whence arises what is called the precession of the equinoxes. And, therefore, when a star is said to be in such a sign of the zodiac, it is not to be understood of that constellation, but only of that dodecatemory, or twelfth part of it. (See Constellations, Precession of the Equinox, and Denderah.)

ZODIACAL LIGHT; a triangular beam of light, rounded a little at the vertex, which is seen at certain seasons of the year, before the rising and after the setting of the sun. It resembles the faint light of the Milky Way, and has its base always turned towards the sun, and its axis inclined to the horizon. The length of this pyramidal light, reckoning from the sun as its base, is sometimes 45°, and at others 150°; and the vertical angle is sometimes 26°, and sometimes 10°. It is generally supposed to arise from an atmos phere surrounding the sun, and appears to have been first observed by Descartes and by Childrey in 1659; but it did not attract general attention till it was noticed by Dominique Cassini (q. v.), who gave it its present naine. If we suppose the sun to have an atmosphere, as there is every reason to believe from the luminous aurora which appears to surround his dise in total eclipses (see Sun), it must be very much flattened at its poles, and swelled out at the equator, by the centrifugal force of his equatorial parts. (See Atmosphere.) When the sun, then, is below the horizon, a portion of this luminous atmosphere will appear like a pyramid of light above the horizon. The obliquity of the zodiacal light will evidently vary with the obliquity of the sun's equator to the horizon; and in the months of February and March, about the time of the vernal equinox, it will form a very great angle with the horizon, and ought, therefore, to be seen most distinctly at that season of the year. But when the sun is in the summer solstice, he is in the part of the ecliptic which is parallel to the equator, and, therefore, his equator, and consequently the zodiacal light, is more oblique to the hori zon. Laplace, however, has made some objections to this theory in his Mécanique Celeste; and Regnier is of opinion that it is owing merely to the refraction of the solar light by the earth's atmosphere.

ZOËGA, George, a Dane, one of the greatest antiquarians of our time, was born Dec. 20, 1755, at Dahler, a village in Jutland, where his father was a clergyman. In 1772, he entered the gymnasium of Altona, and, in 1773, the university

of Göttingen. In 1776, he travelled through Switzerland and Italy, and lived during the winter in Leipsic. In 1777, he returned to his parents, and remained until 1778 in Copenhagen. He now became a tutor, and went, in 1779, with his pupil, to Göttingen, and again to Italy. In 1782, he made a third journey to Italy. On his return, having heard in Paris of the change of ministry in Copenhagen, he resolved to go back to Rome, and reside there the rest of his life. In 1787, he became a Catholic, in order to be able to marry the daughter of the painter Pietruccioli. Zoëga undoubtedly received his first impulse to a profound investigation of antiquity from Winckelmann. (q. v.) He lived entirely with the ancients; and no modern characters or events exerted such an influence over him. In early youth, he had an inclination to melancholy, and his temper was irritable; but he overcame these propensities, and the serene tranquillity of the Greek character took possession of his soul. He was kind, and had a noble heart. He observed strictly the external forms of religion. When he arrived in Rome, professor Adler presented him to cardinal Stefano Borgia, whose favor and patronage he soon obtained. This cardinal had a great fondness for Egyptian antiquities, of which he possessed a rich collection. Zoëga, who was acquainted with the Coptic language, soon began to explain these ancient monuments. In 1787, he published an account of a complete collection of Egyptian coins, with full illustrations. The general approbation bestowed on this work, which furnished important contributions to history and chronology, excited the attention of pope Pius VI, and he employed Zoëga in the explanation of the obelisks. In 1797, he published, at the expense of the pope, his great work on the obelisks-De Origine et Usu Obeliscorum (Rome, 1797)-which procured him great reputation. The Museo Borgiano Veliterno was rich in Coptic manuscripts. Zoëga undertook the difficult task of explaining them, and, in 1810, the fruits of this immense labor were given to the public. Zoëga wrote, in the German language,an Archæological Guide through Rome; and himself accompanied the most distinguished travellers through the city. A treasure of rare knowledge is contained in his Li Bassirilievi antichi di Roma, incisi da Tom. Piroli colle Illustrazioni di Giorgio Zoega, in two folio volumes (Rome, 1808). He often regretted, at a later period, that he had not devoted to

Grecian antiquities the time which he had given to the Egyptian. The Danish government appointed him its consulgeneral for the States of the Church; and, a few days after his death, a diploma of the Danebrog order, intended for him, arrived in Rome. He was professor of the university of Kiel, and member of the academies of Copenhagen, Göttingen, Berlin, Siena, Florence, Rome, &c. He died February 10, 1809. He had eleven. children; but three only survived him, who are supported by the Danish government. Mr. Niebuhr, the historian, offered a prize, some years before his death, for the best essay on Zoëga and his productions.

ZOILUS; the name of a Thracian rhetorician, whose hypercriticisms on the works of Homer have given him a very unenviable kind of distinction with posterity. He was a native of the town of Amphipolis, said to have been born about 270 years before the Christian era, and studied under Polycrates, himself an abusive and illiberal critic. The appellation by which Zoilus delighted to be known, was Homero-mastyx, although his censures were by no means confined to the writings of the great father of epic poetry, but extended indiscriminately and impartially to those of Demosthenes, Aristotle, Plato, and all others whose works came under his lash. His very name has now become a proverb, as applied to all illiberal and captious pretenders to criticism. The period of his death, which was a violent one, is unknown: indeed, the precise era in which he lived is not absolutely determined, Vitruvius making him contemporary with Ptolemy Philadelphus, while Ælian refers him to the ninety-fifth Olympiad.

ZOISITE. (See Epidote.)

Zollikofer, George Joachim, one of the most eminent preachers of the last century, was born at St. Gall, in Switzerland, August 5, 1730. He studied at the gymnasia of Frankfort on the Maine, and of Bremen, and at the university of Utrecht, and, in 1754, became a clergyman at Morat, in Switzerland. In 1758, he accepted an invitation from a congregation at Leipsic, and remained in this situation until his death, January 20, 1788. During these thirty years, he did great good, not only in his congregation, but also among the students of the university in Leipsic. Two hundred and fifty of his sermons have appeared in print. From 1769 to 1788, he published four collections, in six volumes, which went through

several editions. After his death, his remaining sermons were published in nine volumes. The whole of his sermons have been published in fifteen volumes (Leipsic, 1789-1804). Two volumes have of late been translated into English, by reverend W. Tooke; also a small volume of his Devotional Exercises. Zollikofer also published a Hymn Book (eighth edition, Leipsic, 1786), besides translations of some English and French works. Garve (q. v.) wrote on the character of Zollikofer (Leipsic, 1788).

ZONARAS, John; a monk of St. Basil, by birth a Greek, who lived during the latter part of the eleventh and the commencement of the following century. Before he renounced the world for the cloister, he had filled some distinguished offices about the imperial court, but becoming, at length, disgusted with its intrigues, gave himself up to a religious life, employing his leisure hours in the compilation of a History of the World, from the Earliest Periods to the Year 1118. In this work (of which an edition appeared at Paris, in two folio volumes, 1687), he follows, principally, the narrative of Dion Cassius; and all the earlier part of the book is a tissue of fable; but, as he approaches his own times, he becomes more entitled to attention, as all his mistakes arise evidently more from ignorance than design. There is also extant a commentary on the apostolic canons by him. His death took place about the year 1120. ZONE. The whole surface of the earth is divided into five zones-the torrid, northern and southern temperate, and northern and southern frigid zones. The torrid zone extends 234° north and south of the equator; and, twice a year, the sun shines vertically on its inhabitants. This zone is bounded, on both sides of the equator, by the two tropics; that is, the circles in which the sun reaches its greatest distance from the equator. As the rays of the sun here are nearly vertical, a perpetual summer reigns, and day and night, under the equator, are always equal; and even at the tropics, the difference is scarcely an hour. Owing to the nature and situation, however, of the countries in this zone, the heat is not every where the same. The warmest portions are the sandy deserts of Africa: far more temperate are the happy islands of the South seas, and still milder the climate of Peru. This last country contains mountains from whose summits the vertical sun-beams never melt the perpetual snow. The two temperate zones

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extend from the tropics to the polar circles. They contain the most populous countries, and the climate is various. As the distance from the tropics increases, the heat diminishes, the difference of the seasons becomes greater, the days and nights become more unequal, until we arrive at a point where, once a year, the sun does not appear above the horizon during the twenty-four hours, and, once a year, does not set for the same time. The circles passing through these points, parallel to the equator and the tropics, form the limits of the temperate zones, and are called the arctic and antarctic circles. The distance from the tropics to the polar circles, or the breadth of the temperate zones, both in the northern and southern hemispheres, is 43°. All beyond the polar circles, to the poles, is called the frigid zones. No land is known to exist in the southern frigid zone. The northern is habitable, though it produces neither grain nor trees, but only mosses, lichens, and a few bushes. The distance from the polar circles to the poles is 2340; but no one has yet penetrated to the poles themselves. Cook sailed as far as the seventy-first degree of latitude, towards the south pole, which is still more inhospitable than the north, as its winters occur at the time of the earth's greatest distance from the sun. To the north, the eightieth degree has been reached. (See North Polar Expeditions.) The charac teristic of the frigid zones is, that day and night are more and more unequal the nearer you approach the poles; and for days, and even weeks, the sun is above or below the horizon. (See Seasons.)

ZOOGENE (from (wor, animal, and yaras, to produce). On the surface of the ther mal waters of Baden, in Germany, and on the waters of Ischia, an island of the kingdom of Naples, a singular substance is collected, which has been called 200gene. It resembles human flesh with the skin upon it, and, on being subjected to distillation, affords the same products as animal matter. M. Gimbernat (Journal de Pharmacie, April, 1821) has also seen rocks covered with this substance, in the valleys of Sinigaglia and Negropont. Salverte (Des Sciences Occultes, 1829, 2 vols., 8vo.) considers this fact as explaining the stories of showers of pieces of meat, which figure in the number of prodigies of antiquity. The name of zoogene is also given to a substance obtained from bones, by a chemical process which was discovered by M. Gimbernat. Much of it was sent, in 1827, to Greece, and

much of it also was used by the French army, on the expedition to Algiers.

ZOOLITHES (from (wor, animal, and 100s, stone): fossil animal remains, great numbers of which have been found in digging into the surface of the earth. They differ from petrifactions, which are organized bodies, penetrated with stony matter, or completely converted into stony masses, by the gradual removal of the organic matter, the place of which has been supplied by stony deposits. Zoolithes have been divided into six classes-tetrapodolithes, or fossil quadrupeds; ornitholithes, or fossil skeletons of birds; amphibiolithes, or fossil remains of the amphibia, ichthyolithes, or fossil fish; entomolithes, or fossil insects; and helmintholithes, or fossil worms. (See Geology, and Organic Remains.)

ZOOLOGY (from (wov, animal, and Xoyos, doctrine); that part of natural history which treats of animals. It is not confined to a description of the external forms of animals, but embraces all the phenomena of life and animal motion; the internal organization of each individual part; the processes of digestion, assimilation, nutrition, secretion and reproduction; the wonderful instincts, the varied dispositions, and the different degrees of intellect, manifested in the animal creation, from the half-vegetable zoophyte up to man. Although it cannot be doubted that the attention of men was early attracted to an observation of the habits and natures of the lower order of animals, Aristotle seems to have been the first who furnished the world with any methodical information on this subject. His work Hept Zwwv 'loropiat contains a great number of facts and observations. He compares the organization of the lower animals, in its different parts, with that of man, and treats of their mode of generation, habits, organs, &c., with great clearness and sagacity; and his principal divisions of the animal kingdom are so well founded that almost all of them are still substantially admitted. Among the Romans, zoology does not appear to have been at all cultivated, until the time of Pliny, who is the only Roman zoologist worthy of notice. His work (Historia Naturalis) contains multitudes of original traits, though it is only a compilation, and describes the habits and dispositions of animals with great felicity. He adopted, without examination, many fabulous stories, and too often neglected important details. Elian (q. v.) was far inferior to the two above-mentioned writers, and his

Natural History of Animals may be considered as the source of all the falsehood and error which so long disgraced this branch of natural history. Apuleius, and Athenæus the grammarian, are the only names that deserve mention, from the time of Ælian and Pliny to the beginning of the sixteenth century; and they added nothing to the stock of zoological science. At the latter period, flourished, among others, Belon, a French physician, who made the closest approach of any author of that time to any thing like systematic classification, in his De Aquatilibus, and particularly in his De la Nature des Oiseaux (Paris, 1555, folio); Salviani, author of a treatise, Aquatilium Animalium Historia (Rome, 1554, folio), which is superbly illustrated; Conrad Gesner, whose Historia Animalium (Zürich, 1550-1587, 4 vols., folio), arranged in alphabetical order, forms the foundation of modern zoology; and Aldovrandus, the most laborious of compilers, who devoted sixty years to his work on natural history, in fourteen volumes, folio, of which the greater part was published after his death. These earlier writers were followed, in the next century, by Redi and Swammerdam (q. v.), to whom entomology is so much indebted, and by Ray (q. v.), the first naturalist, from the time of Aristotle, who produced any thing like a scientific arrangement. The works of Ray, under his own name, are Synopsis Quadrupedum et Serpentum (1683, 8vo.); Synopsis Avium et Piscium (1713); and Historia Insectorum; and he is also considered to have had a large share in the compositions of his pupil Willoughby. But it was reserved for Linnæus to raise natural history to the rank of a science. Gifted with extraordinary powers of invention and discrimination, a most retentive memory, an unrelaxing industry, and the most ardent zeal in the cause of science, this great man observed, with the acutest sagacity, the subtilest affinities of organized nature. The general character of his works is order, precision, clearness, exactness of description, and an accurate knowledge of relations in detail. Buffon adorned natural history with the charms of eloquence, and was the first who extended its popularity beyond mere scholars and men of science. He was occasionally carried, by the force of his imagination, into unfounded hypotheses; yet he had a truly philosophical spirit, could observe facts, and compare results, and possessed extensive information. The four great naturalists whom we have had

occasion to mention, have exhibited nature under different aspects. Aristotle has shown us the profound combination of its laws; Pliny its inexhaustible riches; Linnæus its wonderful details; and Buffon its majesty and power. Since the time of Buffon, all the departments of zoology have been cultivated with a zeal, a minute accuracy, and an extensiveness of research, before unequalled. Our limits will not allow us to mention all those who have distinguished themselves in the cultivation of the whole field of the science, much less those who, confining themselves to particular branches of it, have yet rendered most important services by the exactness of their researches and the novelty of their views. Among the Germans, Illiger and Blumenbach hold the first rank as zoologists; but it is to France that we are chiefly indebted for the strong impulse which has been given, in our times, to the progress of natural science, and of zoology in particular. The name alone of Cuvier, whose recent death (1832) science deplores, sufficiently indicates the brilliant triumphs of natural history in that country. We have already treated, at some length, of some parts of this extensive subject, under the general heads Animals, Anatomy, and Physiology, and of the nomenclature of particular classes of animals under those of Insects, and Entomology, Conchology, Fishes, and Ichthyology, Ornithology, Reptiles, Serpents, &c.; and we shall now proceed to give some notice of the principal methods pursued by eminent zoologists, with a particular view of mastology, or the classification of the mammiferous animals. The immense number of facts embraced by natural history could never be retained in the memory without an arrangement of divisions and subdivisions founded upon some distinguishing characteristics. Aristotle's system of arrangement was simple, resting on divisions derived mainly from the external structure, food, habits and locality. But though neither human nor comparative anatomy was then sufficiently cultivated to enable him to make the internal structure of animals the basis of

his divisions, yet Aristotle was not insensible to the advantages of a more scientific distribution, and, with his usual sagacity, recommends to succeeding writers to turn

both. Linnæus, proceeding on the general arrangement of Ray, but with many extensions and improvements, divided the animal kingdom into six classes, founded mainly on the differences in the respiratory and sanguineous systems.

CLASS I.-Mammalia. All suckle their young; the heart has two auricles and two ventricles; blood red and warm; viviparous.

CLASS II. Aves (Birds). Characters of sanguineous system as in first class; viviparous.

CLASS III. Amphibia. Heart one auricle and one ventricle; blood red and cold; respiration voluntary.

CLASS IV. Pisces (Fishes). Heart and blood as in amphibia; respiration by gills.

cle and no auricle; sanies cold, colorless; antennæ, or feelers.

CLASS V. Insecta. Heart one ventri

CLASS VI. Vermes (Worms). Characters as in V, except no antennæ, but tentacula.

He then subdivides the Mammalia into seven orders, the distinctions of which are taken from the difference in the num

ber, form and situation of the teeth, without, however, neglecting the feet.

ORDER 1. Primates. Four incisors in each jaw, and one canine.-GENERA: homo, simia, lemur, vespertilio.

ORDER 2. Bruta. No incisors.GENERA: rhinoceros, elephas, trichechus, bradypus, myrmecophaga, manis, dasypus.

ORDER 3. Fera. Six conical incisors in each jaw, for the most part.GENERA: phoca, canis, felis, viverra, mustela, ursus, didelphis, talpa, sorex, eri

naceus.

ORDER 4. Glires. Two incisors in each jaw; no canines.-GENERA: hystrix, lepus, castor, mus, sciurus, myorus, cavia, arctomys, dipus, hyrax.

ORDER 5. Pecora. No fore-teeth in the upper jaw; six or eight in the under. -GENERA: camelus, moschus, giraffa, cervus, antilope, capra, ovis, bos.

ORDER 6. Belluæ. Obtuse fore-teeth in each jaw.-GENERA: equus, hippopotamus, sus, tapir.

ORDER 7. Cete. No uniform charac

of teeth; aquatic pectoral fins; spiracula.-GENERA: monodon, balana, physeter, delphinus.

The other classes are subdivided in a similar manner. We shall enumerate