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named from its origin Noctes Attico ("Attic Nights"), and divided into 70 books (of which the 8th is lost), though without any attempt at order or arrangement, contains a mass of materials, valuable mostly as remnants of lost ancient authors. It was published at Rome (1469), at Leyden (1706), by Gronovius, and at Göttingen (1824), by Lion.

GELON, a ruler of Syracuse, born in Gela in Sicily, died about 478 B. C. He served gallantly as commander of the cavalry, under Hippocrates, tyrant of Gela; on whose death, the people revolting against his sons, Gelon supported the latter, but finally set them aside and assumed the chief power himself (491 B. C.). Called to the assistance of the Gamori, the landed aristocracy of Syracuse, then expelled by the revolted slaves and the popular party, he contrived to become master of that city, appointed his brother Hiero governor of Gela, and by degrees extended his influence and power over all Sicily. He seems to have won the affections of the Syracusans by mildness, by the protection of arts and sciences, and by the aggrandizement of the city, for which purpose he even destroyed Camarina and other towns, and transplanted their inhabitants thither, as well as half the population of Gela. When Xerxes was threatening the invasion of Greece, the Lacedæmonians and Athenians invoked the assistance of Gelon. He promised a fleet of 200 vessels, 20,000 heavy armed and 6,000 light armed infantry, and 2,000 cavalry, upon condition of being elected chief and leader of the allied Grecian armies. To this the Lacedæmonian ambassador, according to Herodotus (vii. 159), replied: "If thou intendest assisting Hellas, go and be commanded by the Lacedæmonians; if thou disdainest to be commanded, stay away." He then sent an ambassador to Delphi, with rich gifts, and orders to greet and acknowledge Xerxes if victorious. Herodotus, however, also mentions a different version of the affair, which vindicates the character of Gelon and the policy of the Syracusans in not assisting Greece. They were fully occupied at home, for the Carthaginians at this juncture invaded Sicily with a great army. Gelon completely defeated them at Himera, on the same day, according to Herodotus, on which the Greeks won the victory of Salamis (Oct. 20, 480 B. C.), but according to Diodorus, on the day of the battle of Thermopyla. He now proposed to resign his power, and restore popular liberty, but the offer was rejected in the assembly, and his exhibition of magnanimity was rewarded with the title of king, which he accepted and bore till his death. The Syracusans erected, against his will, a splendid tomb to his memory, and honored him as a hero. When Timoleon, 130 years afterward, sought to destroy all vestiges of the tyrants, the statue of Gelon was excepted. His brother Hiero was his successor.

GEM (Lat. gemma, a bud), the name of precious stones, prized for their brilliant lustre and splendid colors or perfect limpidity. They possess

also a hardness which renders them susceptible of the highest polish, and capable of retaining unimpaired the forms into which they are cut and the lines or figures that may be engraved upon them. These properties, in connection with their rarity, have given to them the highest value of all substances. The choicest among them have been prized above all other earthly possessions, consecrated by idolatrous nations to their gods, and by the civilized purchased at prices which the wealthiest governments alone could pay, to be held among their most valued treasures. These are commonly called crown jewels, and comprise diamonds, rubies, and emeralds, the largest of which may be hidden in the hand. The finest specimens of these are noticed under their respective titles; and reference may also be made to AGATE, CHRYSOBERYL, CHRYSOLITE, GARNET, SAPPHIRE, TOPAZ, TOURMALINE, &c., for accounts of other species of beautiful gems. These stones, which may be regarded as the richest flowers of the mineral kingdom, are not, like those of the vegetable world, usually presented by nature in their full beauty; but they are found in the form of worn pebbles among the sands derived from the disintegration of the rocks in which they were originally contained. Some, however, are obtained crystallized in the matrix of quartz, calcareous spar, or other gangue of veins in which they were produced, or in geodes, of the dark cavities of which they made with other crystals a lining or incrustation. The crystals may have the perfections of the stone fully developed, but art is not satisfied with the form, and this is almost always sacrificed to fit the stone to the conventional shapes judged best suited to display its highest lustre. The rough pebble, in whose dull exterior only a practised eye would recognize the gem, of course requires the work of the lapidary to develop its beauties. The processes to which the stones are subjected are described in the articles DIAMOND, and LAPIDARY; the method of carving them to bring out from their differently colored layers figures in relief is described under CAMEO; and GEM ENGRAVING will be treated in this article.-To distinguish gems from each other and from their artificial counterfeits, a practised eye has been generally sufficient; but the modern imitations, the manufacture of which is described at at the close of this article, are so perfect, that the tests of comparative hardness and of specific gravity may often be required. The chemical tests which are usually employed to distinguish minerals cannot be applied to these stones on account of the injury they would occasion. The finest collection of gems in the world is that of the emperor of Russia. Siberia has proved a rich field for their production, and all precious stones found there belong to the crown. They are taken to Ekaterinburg, and being cut and polished in the government works, the choicest are selected for the imperial treasury. Clarke in his account of his travels in Russia makes frequent reference to the abundance

of fine gems met with in the cabinets and jewellers' shops, and states that in Moscow they were so much more highly prized than in western Europe, that the most costly gems were sometimes purchased in London to be deposited in Russian collections. Mr. Bayard Taylor made the following observations while at Moscow in 1858: "The shops of the jewellers are interesting, from the variety of precious stones, chiefly from the mountains of Siberia, which are to be found in them. The jewels most fashionable in Moscow at present are diamonds, emeralds, pearls, and turquoises. Opals also bring a large price, but stones of a secondary order, such as topaz, garnet, amethyst, onyx, and aquamarine, are plentiful and cheap. Siberia produces superb emeralds, and the finest amethysts, aquamarines, and topazes I ever saw. The Siberian diamond, which is found in abundance in the Ural mountains, appears to be neither more nor less than a white topaz. A necklace of 75 of these stones, the size of a cherry, costs a little less than $20. I noticed a few fine sapphires, but suspect that they found their way hither from India, through Persia. One jeweller showed me a jacinth, a rather rare stone, with a splendid scarlet fire, for which he demanded 50 rubles. There were also some glorious opals, darting their lambent rays of pink, green, blue, and pearl-white, but their value was equal to their beauty. Malachite and lapis-lazuli, so common in Russian palaces and churches, are dear, and good specimens are not easy to be had." Different Asiatic countries, particularly Hindostan, Pegu, and Ceylon, have been famous from the remotest periods for their rich gems; and in modern times Brazil and Peru have almost rivalled them in these rare productions. GEM ENGRAVING, known also as the glyptic art (Gr. yλurrw, to engrave), was skilfully practised in very remote times. In Exodus xxviii. 17–20, the following stones are designated as those upon which were engraved the names of the 12 children of Israel: sardius, topaz, carbuncle, emerald, sapphire, diamond, ligure, agate, amethyst, beryl, onyx, and jasper. At this early period, as we learn from verse 11 of the same chapter, engraving of signets, and upon the hardest stones, was practised. The Israelites, it is believed, acquired the art from the Egyptians, who are known to have made use of the lapidary's wheel and emery powder, and are supposed to have been acquainted with the diamond and the method of engraving other hard stones by means of it. (Wilkinson's "Ancient Egyptians," vol. ii. p. 67.) __ Specimens of their work are still preserved in European collections, and also of that of the Etruscan artists of a somewhat later period. The Assyrians and Babylonians were very skilful in engraving on gems, great numbers of which have been found in the ruins of their cities. Many of their seals are most delicately and minutely ornamented with various sacred devices and with the forms of animals. The Greeks adopted the art, and practised it with the greatest zeal and suc

cess. Their works of the time of Alexander the Great are still the most perfect specimens. The most distinguished among their earlier artists was Pyrgoteles, who alone was permitted to engrave the head of Alexander, as Apelles only was allowed to paint his portrait, and Lysippus to cast his image in bronze. In the time of the Roman emperors, Dioscorides from Æolia in Asia Minor attained the highest eminence. His head of Io is regarded by some as the finest engraved gem in existence, and others almost equally beautiful are two busts of Augustus, a head of Demosthenes on an amethyst, and various mythological representations. Several of the most skilful artists of Greece established themselves at Rome under the emperors. With the empire the art declined, and though the mechanical execution was not lost, no productions of genius appeared till the 15th century. At this time it became fashionable to make collections of antique gems, and among others Lorenzo de' Medici was especially interested in this object and in encouraging artists to imitate the finest productions, in which they attained great success. The same taste soon spread to France, Germany, and England; and in all civilized countries the art has since been held in high estimation. As applied to the hardest gems, as the diamond, ruby, sapphire, and topaz, it is no doubt carried to a higher degree of perfection than was attained in ancient times, for among the antique engraved gems preserved there are few if any of this class. Engraved gems are for the most part readily referred by connoisseurs to their true period, country, and sometimes to the artist himself. Each had his own cipher, which is commonly found upon the gem, though this is in modern times imitated, together with the peculiar style of the ancient artists and their complete work, in great perfection. Specimens of Egyptian art are recognized by the representations of the peculiar favorite animals and divinities of this people, accompanied with their hieroglyphics. Their gems were engraved almost exclusively in intaglio, and they were of the form designated as scarabai, from the upper surface of the stone, always of the oval form, being cut to represent the beetle. The Etruscans also adopted this form, but their devices more resemble those of the earliest Greek workmanship. Their specimens are distinguished by low relief, a granular border surrounding the engraving, stiffness in the figures, peculiar style of letters and writing, wings given to the deities which the Greeks represent without wings, and names generally attached to the figures. The Greeks also practised chiefly in intaglio, and some of their finest works are in chalcedony and carnelian. The highly famed Dionysiac bull of Hyllus, an artist supposed to have lived before the age of Augustus, is upon chalcedony; and a celebrated specimen in carnelian is the beautiful seal of an unknown artist which once belonged to Michel Angelo, and was afterward preserved in the imperial library at Paris. The engraving represents a vintage, but the design

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has been referred in various learned dissertations to a number of different objects, some of mythological character. Many impressions and copies have been taken of this famous specimen. The engraved gems of the first 15 centuries A. D., excepting the imitations of antique works, generally have designs from scriptural subjects images of Christ and of the Virgin Mary, representations of the Good Shepherd, and often a fish, symbolical of the Saviour, from the letters in its Greek name, xous, being the initial letters in the appellation Inorous Xploтos OEov 'Yios Ewrηp. Some terms employed to designate certain styles of antique geins may be properly noticed here before speaking of the art in modern times. Stones convex on one side are said to be en cabochon; chimære are those with representations of imaginary beings made up of portions taken from different animals; grylli are those with hideous heads, said to be so called from an Athenian named Gryllus, who was extraordinarily ugly; conjugata, or joined, are those with heads represented together upon the same profile-called opposite when they face each other. Engraving was practised both in intaglio and in rilievo, and the two styles were sometimes combined in the same specimen. Stones having differently colored layers, like the onyx, were especially adapted for the rilievo style, for an account of which see CAMEO.-In modern times the finest gem engravers are found among the Italian artists of the 18th century and chiefly those of Florence. Some of their works are hardly inferior to those of the most famous Grecian artists. Flaviano Sirletti of Florence, who died in 1737, was especially distinguished for his copies of ancient gems and exact imitations of the ancient letters. The Costangis and many others also attained great repute; and in the present century are some whose productions, as those particularly of Signor Rega of Naples, rank with the famous antique gems. Among the Germans, Daniel Engelhard of Nuremberg, a friend of Albert Dürer, was celebrated for his skill in engraving crests and arms. He died in 1552. The works of the Pichlers, father and son, who came from Tyrol, are of the highest merit, especially those of the father. The son was much in Italy, and is often spoken of as an Italian. The celebrated Poniatowski collection of antique gems has recently been credited to the elder Pichler. Natter of Swabia, who died in 1763, was not only a workman of the most delicate skill and refined taste, but a student and author also, and published in 1754 the only treatise specially devoted to his art: Traité de la méthode de graver en pierres fines. From this work it appears that the ancients employed the same sort of tools and the same methods as those in use at the present day. The modern practice is described by Holtzapffel in vol. iii. of his "Mechanical Manipulation." He speaks in high terms of the works of English artists, specimens of which, collected in Italy, have been credited to the artists of that country; and he names as especially distinguish

ed, Wray, Burch, Marchant, and Charles and Henry Weigall; to which names may be added Pistrucci and the Wyons. The apparatus employed in engraving consists of a foot lathe attached to a small table, upon which is fixed a little pillar for holding the horizontal pulley, which is the receptacle for the cutting tool. This part of the apparatus is called the mill. The tools are soft iron wire spindles carefully annealed and nicely fitted to the hollow axis of the pulley. Only one is used at a time. When set in its place it projects through the bearings of the pulley, one end extending horizontally on the right hand side of the operator, who sits at his work in front of the table. This extremity of each tool is fashioned for its special work. Most of them terminate in a small disk, the edge of which, as it rotates rapidly, cuts lines in the stone held up against it, the tool being fed with diamond dust and oil. The larger sized disks are only about inch in diameter, and from this they are made of decreasing sizes down to of an inch, when the disk can scarcely be distinguished by the eye from the stem. They are also variously shaped for special kinds of cutting. The stone intended to be engraved is usually shaped by the lapidary, and is sometimes set by the jeweller before it is engraved. If not set, the engraver secures it to a wooden handle by the cement known as the lapidary's; or if set, he secures it in a notch in a piece of cork. The polish is removed by roughening the face with a suitable cutting powder, as the tools work better upon a rough surface, and the outline of the design, which is next marked with a brass point, is the more conspicuous. The area thus enclosed is then sunk by the tools to a suitable depth; and within this the details of the design are successively introduced and excavated. For the parallel lines called color lines, a thicker disk with two cutting edges is employed, its form being that of a little pulley; the two edges are just as far apart as the lines they are intended to cut, and as one pair is cut the stone is moved so as to bring the outer edge of the disk into the groove marked by the other edge, and thus the work goes on step by step over the surface to be thus "colored." The plan must be perfectly understood by the artist at the commencement of his work, and as it goes on he watches the effect produced with the aid of a magnifying glass conveniently attached to a stand over the tool, and occasionally takes a proof of his work in wax. After the stone is engraved the polish is restored to the flat surface by a pewter polishing disk or lap fed with rotten stone and water. The engraved portions are polished with great care, first by using in the mill copper tools charged with diamond powder; this buries itself more deeply in the copper than in the iron tools, and a smoother surface is thus obtained. Box wood tools charged with still finer diamond powder are next used, and after these copper tools charged with rotten stone and water. The harder gems, excepting

sion in a heated Hessian crucible to continue 30 hours. Topaz, to 1,000 of the same quality of strass, requires 40 of perfectly transparent yellowish orange-red glass of antimony and 1 of purple of Cassius; or, instead of these, 10 parts of oxide of iron. With the first the tint varies with the temperature and the time fusion has continued. Rubies are obtained by melting 25 parts of oxide of manganese with 1,000 of colorless strass; but the most perfect specimens are made by selecting the opaque mass often produced by the topaz mixture, which is transparent at the edges, and in thin plates red and transparent, and melting one part of this with 8 of strass. After being 30 hours in fusion it will give a fine yellowish glass; remelted with the blowpipe, the glass is like rubies of the finest water. Amethyst is made with 8 parts of oxide of manganese, 5 of oxide of cobalt, and 0.2 of purple of Cassius, to 1,000 of strass; the Syrian garnet, formerly called carbuncle, with 500 parts of glass of antimony, 4 of purple of Cassius, and 4 of oxide of manganese, to 1,000 of strass. In all these preparations success depends on a thorough pulverization and mixture of the ingredients; the use of the same sieve for sifting different mixtures should be scrupulously avoided; the fusion should be long continued at a graduated and uniform maximum temperature, and the mixture be annealed in cooling.-The researches and experiments of M. Ebelmen are of a higher order of art. He conceived the idea in 1847 of forming various mixtures with some ingredients volatile at very high heat. By the dispersion of these in the furnace the other ingredients should crystallize, as substances held in solution in liquids crystallize when these are evaporated. He thus proposed to produce the ruby, corundum or sapphire, and other precious stones. The volatile solvents or fluxes he employed were principally boracic acid and borax. The spinelle ruby, among the first minerals he imitated, was obtained by mixing together 30 parts of magnesia, 25 of alumina, 1 of chlorate of potash, and 35 of boracic acid, and subjecting 500 grammes (7,716 grains) of the compound to high temperature in the muffle of a furnace for 8 days. The crystals measured 0.197 inch on a side. Chrysoberyl was produced in crystals with faces of 0.24 inch, perfectly transparent, and scratching topaz, from a mixture of alumina 12 grammes, glucine 3.5, carbonate of lime 10, and fused boracic acid 14 grammes. The object of the lime was to form a fusible borate for holding the other ingredients in a condition favorable for crystallization. Chrysolite in well defined crystals resulted from silica 4.5, magnesia 6.15, and boracic acid 6. Transparent crystals of pure alumina, which are sapphire or corundum, and which presented the same hardness and specific gravity with this mineral, were a product of alumina thus fused with 3 or 4 parts of borax, or of 10 parts of alumina with 4 of silica and 16 of borax. M. Ebelmen employed also as fluxes the salt of phosphorus and the carbonates

the diamond, which is engraved with the greatest difficulty, are better adapted for this process than those of softer quality. The latter are liable to hold the diamond powder and cause it to wear out the tools; they do not when finished present such smooth and highly polished surfaces as the harder stones. The amethyst is considered as soft a stone as can be cut very smoothly. Carnelian and bloodstone are of close texture, and admit of excellent work; the ruby cuts slowly, but small pieces are apt to flake off. The sapphire is firm and close; it cuts slowly, but presents beautifully smooth surfaces.-ARTIFICIAL GEMS. The great value attached to precious stones led at an early period to successful attempts to imitate them. The Egyptians possessed the art of coloring glass, and among their mixtures they produced excellent imitations of the most beautiful gems, so that, as Pliny states (xxxvii. 12), it was difficult to distinguish the false from the real. Their artificial emeralds, sapphires, and hyacinths are spoken of by various ancient authors. Some of the first named were of such gigantic size that they were used in the construction of statues, as of that of Serapis in the Egyptian labyrinth, 13 feet in height. Another presented by the king of Babylon to an Egyptian Pharaoh was 6 feet long and 4 broad; and an obelisk in the temple of Jupiter 60 feet high and 6 feet broad was composed of 4 artificial emeralds. (Wilkinson's "Ancient Egyptians," vol. ii. p. 63.) These were very extraordinary productions if made only of pieces of colored glass. Seneca also makes mention of one in his time who manufactured artificial emeralds. Beckmann states that in some ancient collections at Rome are pieces of colored glass, which were once used as jewels. In the Museum Victorium are seen a chrysolite and emerald of faultless execution. In the 17th century the discovery of the preparation of gold and binoxide of tin, called purple of Cassius, afforded the means of giving a ruby red color to glass, and artificial rubies were then first made, especially by one John Kunkel, afterward Löwen stiern, inspector in 1679 of the glass houses in Potsdam. In modern times the art has been wonderfully perfected by the French, chiefly through the genius of M. Donault Wieland. A glass called strass, of great lustre and perfectly transparent, of which the ingredients are given in the article GLASS, is prepared as the basis of the composition. It resembles the diamond in high refractive power as in its other qualities, except hardness. That it may be free from color its ingredients must be absolutely pure; and care must be exercised in selecting crucibles least likely to impart color to the fused mixture. The pure glass without addition of other matters may be cut into the forms adopted for the diamond and pass for this gem. Emerald is imitated by adding 8 parts of pure oxide of copper and 0.2 part of oxide of chromium to 1,000 parts of strass; sapphire, by adding 15 of pure oxide of cobalt to 1,000 of very white strass, the fuVOL. VIII.-9

of potash and of soda, all which are volatile at high temperatures, and by means of these solvents reproduced many other minerals, as he announced to the academy in 1851. His death shortly after terminated these interesting researches.-The great establishment of M. Bourguignon in Paris is the most famous manufactory of artificial gems in the world. About 100 workmen, beside many women and girls, are constantly employed in preparing and fusing the mixtures, cutting and polishing the stones, and lining the imitation pearls with fish scales and wax. The sand used to furnish the silica is from the forest of Fontainebleau; and its quality is so highly esteemed that much is exported for similar use elsewhere. The gems are such perfect imitations that they can be distinguished from genuine stones only by the closest scrutiny of those experienced in such matters. The great hardness of the natural stones it is found most difficult to imitate, and there is a want of permanency in the qualities of most of the imitations, which at last causes their true character to appear.-"A Popular Treatise on Gems," by Dr. L. Feuchtwanger, was published in New York in 1859.

GEMINI (the twins), the 3d constellation in the zodiac, so named from its 2 brightest stars, to which the names Castor and Pollux are given, and which are about midway between Aldebaran and Regulus.

GEMISTUS, GEORGE, surnamed PLETHO, a scholar and philosopher of the 14th and 15th centuries, born in Constantinople, and said to have lived to the age of 100. He held a high position at the court of the emperor Manuel Palæologus, and at the council of Florence in 1439 opposed the union of the churches of the East and the West. Being subsequently banished from his country, he found an asylum in Italy, and declared himself in favor of the Latins. While the philosophy of Aristotle was still reigning, he became an enthusiastic votary of the Platonic theories in metaphysics and natural theology, and being admitted to the court of the Medici, prompted Cosmo, the head of that family, to found his celebrated Platonic academy. His treatise in praise of Platonism inaugurated the long quarrel between the disciples of the two great masters of antiquity, which produced a profound study of their systems. Gemistus, however, mingled with the Platonic philosophy the notions of the later Alexandrian school and of the spurious writings attributed to Zoroaster and Hermes, and revived in the West that eclecticism, half Christian and half pagan, half oriental and half Greek, which flourished during the decline of the Greek philosophy at Alexandria.

GEMPAK, SOUGITA, a Japanese physician, one of the first in his country that became acquainted with western learning, born about the middle of the 18th century. After studying at Miako and practising medicine in the Japanese manner, he learned that the Dutch, then the only Europeans trading in Japan, were more skilful in treating diseases, because they had a

better knowledge of anatomy, and rejected the Chinese superstitions and prejudices. He therefore after long labor mastered the Dutch language, translated into Japanese Kulm's treatise on anatomy (5 vols. large 8vo., including one of well executed plates, Miako, 1773), and acquired a knowledge of the European sciences and discoveries, which he imparted to his countrymen. GEMSBOK. See ANTELOPE.

GENEALOGY (Gr. yevos, pl. revea, race, and λoyos, discourse), an account or history of the origin, lineage, and relationships of a distinguished person or family. Such accounts are auxiliary to historical science, and interesting not only to persons who feel a more or less natural curiosity about their ancestors, but also to the historian as elucidating the often complicated relations of dynastic families, claims and controversies of succession, &c. They are also of importance in legal cases concerning claims to inheritance, and indispensable in states in which the enjoyment of certain rights is conditioned by qualifications of lineage or descent. The practical results of genealogical researches are given in lists or accounts of ancestors and their descendants, or in pedigrees or tabular views of the members of any particular family, and of their mutual relations. They are sometimes represented in the form of a tree (arbor consanguinitatis), giving a clear view of the various branches of the family and the degrees of descent from the common progenitor, who is generally represented in the root, sometimes in the stem. Genealogical tables are either descending or ascending. The former are chiefly used in historical records, presenting the descendants of a certain person in the order of procreation; the latter in documents of nobility, serving to show the claims of any man or family to the titles of paternal and maternal ancestors. Sometimes both forms are used together. Persons descended one from another successively form a direct line; those descended from a common progenitor, but not one from another, a collateral line. The members forming the first 7 degrees in a direct ascending line are called in Latin pater (father), avus (grandfather), proavus (great-grandfather), abacus, atavus, tritavus, protritavus; the corresponding 7 members in a descending line are called filius (son), nepos (grandson), pronepos (greatgrandson), abnepos, atnepos, trinepos, protrinepos; those above or below the 7th degree are termed respectively majores (ancestors) and posteri (posterity). Thus the number of the degrees does not include the person from whom we begin. The same is the case in counting the degrees of a collateral line; two cousins, for instance, are said to be at the 4th degree from each other, there being 4 persons, the cousins and their parents, beside the common progenitor or head. The collateral line embraces the agnates, or the kindred on the father's side, and cognates, or the kindred on the mother's side. -The fabulous as well as historical records of the ancient nations contain numerous genealogi

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