his commission, intending to fit himself for the practice of the law; but at the commencement of the war of 1812 he returned to the army, with which he remained connected until his death. At the battle of Chrystler's field, fought Nov. 11, 1813, he rendered important services by covering the retreat of the American forces with his regiment, the 25th, and he subsequently commanded at Fort Erie when the night assault by the British troops under Gen. Drummond was repulsed. For his conduct during the siege of this place, where he was severely wounded, he was promoted to be brevet major-general, having passed during the war by successive promotions through the inferior grades from lieutenant-colonel upward, and received the thanks of congress and a gold medal. He received similar testimonials from the states of Virginia, Tennessee, and New York. He was subsequently engaged in the Creek and Seminole wars, and held the chief command of the southern military district till 1821, when the western division was assigned him. At the commencement of the Mexican war he called out a large force of the southern militia, without awaiting orders, and without obtaining any result commensurate with the expense, for which he was tried by a court martial, but not censured.

GAINSBOROUGH, THOMAS, an English landscape and portrait painter, born in Sudbury, Suffolk, in the early part of 1727, died in London, Aug. 2, 1788. At a very early age he manifested a taste for drawing. Allan Cunningham says: "At 10 years of age, Gainsborough had made some progress in sketching, and at 12 was a confirmed painter." At the age of 15 he was sent to London and placed under the instruction of Gravelet the engraver and Hayman the painter, and soon began to paint landscapes and portraits. But his position did not improve until his marriage in 1746 with a young lady named Burr, of striking beauty, and a fortune which laid the foundation of her husband's independence. He then resided successively in Ipswich and Bath, and in 1774 returned to London, where some portraits which he painted of members of the royal family at once gave him a name and ample employment. He passed the remainder of his life in London, where Sir Joshua Reynolds, his great rival and friend, had settled before him. In 1768 he was chosen one of the original 36 academicians, and from that time until 1784 he sent numerous pictures to the academy, excepting during the 4 years from 1773 to 1777, when, as was supposed, some dispute with Sir Joshua Reynolds deprived the academy of his contributions. It is said that Chatterton sat to him during this interval, and that the portrait was a masterpiece. As a landscape painter Gainsborough achieved the highest excellence, and was the first of his class in England to show any real originality. The "Life of Thomas Gainsborough," by George William Fulcher, edited by his son, appeared in London in 1856.

GAIUS, or CAIUS, a Roman jurist, who flour

ished during the reigns of the emperors Hadrian, Antoninus Pius, and Marcus Aurelius. Of his personal history little or nothing is known, and even the spelling of his name has been a subject of controversy. From references in the Digest it would appear that he was the author of upward of 15 works, of which the Institutes was by far the most important. This is supposed to have been the first work of the kind not compiled from previous sources, and to have afforded the first instance of a popular manual of Roman law in the sense of modern elementary text books. Such was the estimation in which it was held that after a lapse of 4 centuries from the period of its publication it was incorporated almost bodily into the celebrated Institutes prepared by the order of Justinian. The fame of Gaius as a legal writer, although amply sustained by the latter work, is established on a firm basis by the accidental discovery of a nearly perfect copy of his original treatise, supposed to have been lost after the promulgation of Justinian's compilation. In 1816 Niebuhr in a transient visit to Verona examined a palimpsest in the cathedral library, containing 251 pages, of which one detached and undefaced leaf of 2 pages had been described and partly published by Scipio Maffei 60 years before, with a conjecture that it was part of a compendium of Justinian's Institutes. With this exception the whole original manuscript had been washed and sometimes scratched out and overlaid with the epistles of St. Jerome, and 63 pages had been written over a second time; yet Niebuhr succeeded in restoring and deciphering a portion of it, and at once concluded that it was a treatise of some ancient jurist of celebrity, probably Ulpian. He communicated the results of his labors to Savigny, who published them, together with a learned note suggesting that the ancient text of the parchment was the lost Institutes of Gaius. The sensation caused by these investigations induced the royal academy of Berlin in 1817 to send two accomplished civilians, Göschen and Hollwegg, to Verona, who, after incredible labor in deciphering the characters on the parchment, succeeded in making a transcript of the original writing with the exception of 3 leaves and a few scattered passages which were illegible. A comparison of the work thus recovered with the quotations in the Digest, and its agreement with the Institutes of Justinian, confirmed Savigny's conjecture, and the discovery, by clearing up difficulties in the interpretation of ancient jurisprudence before regarded as hopeless, has been considered to form an era in the study of Roman law. Several editions of the text have been published, that of Göschen of 1842 being considered the best; and commentaries on detached portions by Van Assen, Heffler, Klenze, Böcking, and others, have appeared; but no edition of the whole work with a good commentary has yet been published.

GAJ, LJUDEVIT, a Slavic journalist, born in Croatia about 1810, studied in Hungary and

Germany, and after having visited St. Petersburg, became one of the chief agitators for a national union of the south-Slavic tribes. He established a national printing office in Agram, introduced a new system of uniform orthography for the Croatian, Slavonian, and Dalmatian dialects, called collectively the Illyrian language, and commenced in 1835 the publication of the "Croatian News." In the following year this paper assumed the title of "Illyrian News," but when the south-Slavic movement, though exceedingly effectual as a counterbalance to the national movement of the Magyars, seemed to become threatening to the interests of Austria, the appellation Illyrian was prohibited, and Gaj styled his journal Croato-Slavono-Dalmatine. In 1848, after the outbreak of the revolution in Austria, Gaj headed a deputation to the emperor, and returned from Vienna with the title of councillor. He continued his agitation against the Magyars, and was elected to the Slavic congress of Prague by the high school of Agram. In consequence of renewed political activity, which appeared untimely to the government, he was arrested for some time in 1853. He is also popular as a poet.

GALACTOMETER (Gr. yaλa, gen. yaλakтos, milk, and perpov, measure), an instrument for determining the specific gravity of milk, as an indication of its quality. The common hydrometer may be used for this purpose, but a better instrument is that called the centesimal galactometer, invented by M. Dinocourt. This is a glass tube made to float upright in the liquid, and surmounted with a stem upon which are two scales, one intended to be used in skim milk, the other in milk from which the cream has not been removed. The normal range of each quality is designated upon one of the scales, and the divisions above are intended to mark hundredths of water that has been added. Though the specific gravity of genuine milk commonly is found between 1.026 and 1.031, the determination of this is a very uncertain test of its purity. Cream being specifically lighter than milk, its removal leaves the fluid comparatively heavier; water might be added to this, and the specific gravity be thus brought to that of genuine milk. The instrument therefore should be used only in connection with another called the lactometer, the object of which is to determine the proportion of cream present. This being known, and the specific gravity ascertained with the accuracy due to the graduation of the galactometer, the quality of the milk can be more correctly determined than by the use of other instruments.

GALAM, or KAJAAGA, a country of West Africa, in Senegambia, intersected by the parallel of 14° 45' N. and by the meridian of 13° 10' W. It consists of a narrow but densely populated strip along the left (S. W.) bank of the Senegal river, bounded S. by Bondoo and Bambook, and divided by the Faleme into 2 parts, the W., called Lower Galam or Goye, and the E., Upper Galam or Kamera. It is a

mountainous region, abounding in fine scenery, and favored with a fruitful soil and fertilizing streams. The lion, elephant, wild boar, ape, hippopotamus, and crocodile are among its indigenous animals. The inhabitants, who occupy a string of towns on the Senegal, are mostly Serawollis. They are described as a robust, agricultural people, not ignorant of trade, and largely employed as carriers. They exchange the products of the country for European goods, and at one time Galam, or Fort St. Joseph, their capital, was the centre of an active commerce with the French and an important slave depot. Pagan worship is gradually giving way to Mohammedanism; every town has its mosque and priests, and the latter form the wealthiest and most respectable class of the nation. Honesty is a virtue little understood; the boundless exactions of the native chiefs, dignified by the name of customs, have doubtless contributed more to the destruction of commerce than almost any other cause; but in other respects their treatment of whites is friendly. The government is in the hands of a ruler called the tunka, whose power, however, is limited by a representative assembly. He derives his authority by collateral succession. The country was visited by Mungo Park in 1795-'6.

GALAPAGOS ISLANDS, a group of islands in the N. Pacific ocean, comprising 11 of considerable size and a great number of islets, about 600 m. from the coast of Ecuador, to which state they belong. They lie between lat. 1° 30' S. and 0° 44' N., and between long. 89° 20′ and 92° 10' W. The largest of the group, Albemarle island, is 75 m. long and about 15 m. broad, and its highest summit is, according to Humboldt, 4,636 feet above the level of the sea. These islands are all of volcanic origin, and of comparatively recent formation. Their general appearance is not at all inviting, but in the interior of Charles island is an extensive plain, cultivated by convicts, and producing luxuriant crops of tropical fruits and vegetables. These islands so abound in elephant or land tortoises, which in Spanish are called galapagos, that they have derived their name from them. In 1882 the republic of Ecuador converted Charles island into a penal settlement, and sent thither a small colony. When Capt. Fitzroy visited it in 1835, there were 80 houses and some 200 souls, chiefly convicts, on the island. Humboldt in his "Cosmos" says: "Scarcely anywhere else, on a small space of barely 120 or 140 geographical miles in diameter, has such a countless number of conical mountains and extinct craters (the traces of former communication between the interior of the earth and the atmosphere) remained visible. Darwin calculates the number of the craters at nearly 2,000. When that able observer visited the Galapagos in the expedition of the Beagle under Capt. Fitzroy, two of the craters were simultaneously in a state of igneous eruption. On all the islands, streams of a very fluid lava may be

seen, which have forked off into different channels and have often run into the sea. . . . On the largest and most westerly island of the Galapagos group, Albemarle, the cone mountains are ranged in a line and consequently on fissures. The western bay, in which the peak of Narborough, so violently inflamed in 1825, rises in the form of an island, is described by Leopold von Buch as a crater of upheaval, and compared to Santorino. Many margins of craters on the Galapagos are formed of beds of tufa, which slope off in every direction. A part of what in the old descriptions is called tufa, consists of palagonite beds, exactly similar to those of Iceland and Italy, as Bunsen has ascertained by an exact analysis of the tufas of Chatham island, the most easterly of the whole group.'

GALATIA, a province of Asia Minor, lying N. E. of Phrygia, of which it was once a part, and called Gallo-Græcia or Galatia from the Gauls, who, having left the army of Brennus, conquered this region and settled in it. No ancient geographer has laid down with precision the limits of Galatia. Its inhabitants, though intermixed with the Greeks, still retained their native language down to the days of the apostle Paul. Callimachus calls them "a foolish people;" and Hilary, himself a Gaul, as well as Jerome, speaks of them as unteachable. Though marked by that warmth and volatility of character for which the Gauls in all ages have been noted, they were less effeminate and less debased by superstition than the natives of Phrygia, and therefore more ready to receive the gospel when it was made known to them. Paul first preached Christianity and organized churches in Galatia. He was there once with Silas and Timothy (Acts xvi. 6) about A. D. 53, and again, several years later, on his return from Corinth (Acts xviii. 23).

GALATIANS, EPISTLE TO THE, addressed by St. Paul to "the churches of Galatia," and forming one of the canonical books of the New Testament. There is little evidence and much diversity of opinion as to when and where it was written. In the Galatian churches were many Hebrew converts, who had incorporated Jewish rites with the ordinances of Christian worship. Some of them seem even to have questioned the divine commission of Paul, with a view of exalting the authority of Peter, who was believed to be at variance with him concerning the relation of the Jewish to the Christian ceremonial. To recall the Galatians to the simplicity of the gospel was the object of Paul in this epistle, in which he vindicates his apostolic commission (i., ii.), urges the doctrine of salvation as the cardinal truth of Christianity, illustrates the relation of the Christian to the Jewish church (iii., iv.), and concludes with exhortations and benedictions.

GALATZ, or GALACZ (anc. Axiopolis), a town and the only port of Moldavia, capital of the district of Kovourloni, on the Danube, just below the mouth of the Sereth; pop. about 36,000. It is an important commercial town, one of the two

ports on the Danube open to foreigners, and an entrepot for most of the traffic between Germany and Constantinople. Steam packets ascend the river to Vienna, and a line of vessels established by the Austrian Lloyd company connects Galatz with Trebizond and Constantinople. In 1847 steamboat communication was also opened with Odessa. Galatz is a free port, is accessible by vessels of 300 tons burden, and though distant about 80 miles from the sea promises to become the chief emporium on the Danube. Since the removal of many oppressive commercial regulations in 1829 it has made great advances. It exports wheat, maize, barley, tallow, hides, skins, bristles, bones, jerked beef, lard, butter, wool, linseed, yellow berries, barilla, coarse cheese, timber, &c., and imports cotton goods, iron, steel, hardware, sugar, coffee, olives, and olive oil. The value of the exports, chiefly maize, in 1856, was about $4,000,000, and of the imports $5,000,000. The trade was formerly monopolized by the Greeks, and is still chiefly in their hands, although the English and other merchants now participate in it more than formerly. Galatz consists of an old and a new portion, the former of which is dirty, ill built, and crowded with miserable wooden huts. The latter has a number of handsome stone buildings, Greek churches, a convent, a hospital, and a large bazaar. A battle was fought here between the Turks and Russians in 1769; the Russians took the town in May, 1789; and the Turks gained a victory here in August of the same year. Between 1848 and 1856 Galatz was on several occasions occupied by Turkish, Russian, and Austrian troops.

GALAXY (Gr. yaλagias Kukλos, milk circle, the milky way), an irregular band of whitish light surrounding the heavens, stretching in winter evenings from S. E. to N. W., in summer from S. W. to N. E., and caused, as may be seen with telescopes of low power, by numerous stars too faint to be seen singly by the naked eye. It is the almost unanimous opinion of astronomers that this faintness arises chiefly from distance, so that the sun and the fixed stars may be considered as the central portion of an immense flat cluster of stars whose circumference is the milky way. Other specimens of such clusters of stars, it is believed, are visible in some of the great nebulæ.

GALBA, SERVIUS SULPICIUS, a Roman emperor, born near Terracina, Dec. 24, 3 B. C., died Jan. 15, A. D. 69. Inheriting great wealth and possessing great talents, it was predicted both by Augustus and Tiberius that he would become the head of the Roman world. He attained the prætorship in A. D. 20, and the consulship in 33, carried on a war in Gaul in 39 against the Germans, was intrusted with the administration of Africa in 45, lived in retirement for several years under Nero, but in 61 was invested with the government of Hispania Tarraconensis. He was faithful to the empire till in 68 Vindex rebelled in Gaul, and his own assassination was plotted by Nero. He then

took the title of legate of the Roman senate and people, marched toward Rome, and upon the death of Nero received the imperial dignity from the senate. He offended the prætorian guard by refusing the donative which had been promised in his name, and completed his ruin by adopting Piso, a noble young Roman, for his successor. Otho, who had hoped for the adoption, immediately formed a conspiracy among the soldiers, and Galba was murdered in the forum 7 months after the beginning of his reign. GALBANUM, a gum resin obtained from India and the Levant. The tree which produces it is not known with certainty. On doubtful authority it has been referred to the bubon galbanum of the eastern coast of Africa, to the ferula ferulago of Linnæus, and the F. galbanifera of Lobel. Lindley named the tree from which he supposed it came opoidia galbanifera, and Don from some seeds found in the gum proposed a new genus, galbanum, with the specific name officinale for the tree producing the gum, or rather the seeds found in it. A German traveller, F. A. Buske, saw the galbanum plant growing on the shores of the Caspian with the gum exuding from it, and according to his description it is a ferula, very similar to the F. erubescens of Boissier, if not this species. The drug is imported in massive lumps of irregular shapes, apparently made up of agglutinated tears. They are of brownish yellow color, sometimes greenish, the tears sometimes translucent and of a bluish or pearl white color. Its consistency in cold weather is that of wax; in warm weather it is soft and adhesive, and at 212° F. it can be strained, a process requisite to separate the stems and other impurities with which it is commonly mixed. When quite cold it is brittle and may be pulverized. The taste of galbanum is bitterish, hot, and acrid, and its odor balsamic, peculiar, and disagreeable. It is wholly soluble, except impurities, in dilute alcohol; less so in ether. Its specific gravity is 1.212; and its composition, by the analysis of Meissner, is as follows: resin, 65.8; gum, 22.6; bassorin, 1.8; volatile oil, 3.4; bitter matter with malic acid, 0.2; vegetal remains, 2.8; water, 2; loss, 1.4; total, 100. An essential oil is obtained by distillation, of a fine indigo blue color, which it imparts to alcohol. Varieties of galbanum of somewhat different qualities are occasionally met with. The uses of galbanum are medicinal, rarely as an internal remedy, though it possesses stimulant, expectorant, and antispasmodic properties, on account of which it is sometimes prescribed in catarrhs, chronic rheumatism, &c. Its most useful application is in the form of a plaster, alone or in combination with other substances, for promoting resolution or suppuration of indolent swellings.

GALEN (GALENUS), CLAUDIUS, a physician of antiquity, born in Pergamus in Mysia, A. D. 130, died, according to Suidas, in 200 or 201, but according to his Arabic and some other biographers, from 10 to 18 years later. Galen received the rudiments of his education from his father, and

when 15 years of age he began to study logic and philosophy. Two years afterward he was placed under the best instructors in the science of medicine; and at about the age of 20, after the death of his father, he travelled into various countries to complete his studies. He was absent 9 years from Pergamus, and when he returned he was appointed city physician to the school of gladiators. Some popular commotions having arisen in Pergamus a few years after his appointment, he went to Rome, where he remained 4 years and acquired great reputation for skill in anatomy and medicine. As soon as the troubles in Pergamus had passed away, Galen hastened back with the intention of remaining there; but hardly had he reached his destination when he was summoned by the emperors Aurelius and Verus to attend them at Aquileia in Venetia, where a fearful pestilence raged in the camp. The emperors set out for Rome shortly after Galen presented himself. Verus died of apoplexy on the way, and Galen accompanied Aurelius to the capital. When returning to the camp after the apotheosis of his colleague, Aurelius urged Galen to accompany him, but the latter declined under pretence that Esculapius had enjoined him to remain. How long he sojourned in Rome during his second visit is uncertain, but while there he continually added to his fame by his lectures, writings, and successful practice. We know little more of his latter days than that he ultimately returned to his native city, and died there. Galen was not only the most eminent physician, but also one of the most learned and accomplished men of his age. He was a very voluminous writer on medical and philosophical subjects. There are still extant 83 treatises of his, and 15 of his commentaries on various works of Hippocrates, beside the fragments of his lost works and those writings which are falsely attributed to him. The best edition of his works is that by Kühn, which appeared at Leipsic, 1821-33, in 20 vols. 8vo. Writings attributed to him were discovered and published in Paris by Minas in 1844, and by Daremberg in 1848.

GALENA, sulphuret of lead, the ore which furnishes most of the lead of commerce. It occurs in highly crystalline masses, which separate into cubical fragments. Its structure is also granular, and sometimes fibrous. Freshly fractured, it presents a brilliant lustre like polished steel, which changes by exposure to a dull leadgray color. Its hardness is from 2.5 to 2.75; its specific gravity 7.25 to 7.7. Its composition, represented by the symbol PbS, is lead 86.6, sulphur 13.4; but it often contains other metals, as antimony, silver, zinc, iron, and copper, as well as the substance selenium. It is also largely intermixed with the earthy gangues that form the principal portion of the veins in which it is found. From these, and from the sulphurets of zinc and the pyritous copper and iron usually associated with the ore, it is separated as far as practicable before smelting by the processes of stamping or crushing, jigging, &c. (See LEAD,

and METALLURGY.) In some veins and beds it is frequently found in large groups of cubical crystals, which are very free from mixtures with foreign substances. In this form it is met with in the fissures in the limestone of the lead region of Wisconsin, Iowa, and Illinois, imbedded in the clay with which the fissures are filled. Galena is a valuable ore for the silver it often contains, as well as for the lead. In reducing the ore by smelting, the silver all goes with the lead, which is run out; and from this it is afterward separated either by the process of cupellation, or parting by crystallization, or other method. The lead ores do not, however, all contain silver enough to render its extraction profitable; and of those worked in the United States, only the ores of Davidson co., N. C., are sufficiently argentiferous for the separation of the silver to be an object, and yet the separation is so cheaply conducted that 3 oz. of silver to the ton of lead will pay for the operation. Galena much richer in silver than this is a product of numerous veins in the granitic and metamorphic rocks of New England and other parts of the United States; but the more argentiferous it is, the less certain is the yield of the veins in quantity, and none of this character has been found profitable to work. In Cornwall and Devonshire, England, mines of argentiferous galena have been worked profitably for centuries, even when a product of 9 or 10 oz. of silver to the ton of silver-lead was required to pay the expense of separation. The richest metal was from the ores of mines near Beer Alston in Devonshire, which yielded from 80 to 120 oz. of silver to the ton of lead; one portion of the mines, known as the South Hooe, yielded lead containing 140 oz. of silver to the ton. These mines, though now of little importance, were celebrated for their production in the time of Edward I. and II. Other mines produce, some 40, some 50, and some 70 to 100 oz. of silver. In Ireland the product of the lead ores in silver in 1851 was 3,860 oz. of the value of £1,029 68. 8d. The average yield of the lead was 7 oz. to the ton. The lead from the mine of Shallee yielded 25 oz., of Luganure 8 oz., of Ballyhickey 15 oz., and of Kilbricken 120 oz. Argentiferous galena is a common product of mines upon the continent of Europe, and also of Mexican mines. Among the localities in the United States where it is met with are Shelburne and Eaton, N. H., the lead obtained from the ores of each locality yielding from 3 to 7.53 lbs. of silver to the ton; Middletown, Conn., 40 to 70 oz.; Uxbridge, Mass., a specimen from one of the small veins of which yielded at the rate of 13.53 lbs. troy to the ton; Ancram, Columbia co., N. Y., 25 to 30 oz. to the ton of lead; Ellenville, Ulster co., N.Y., 12 oz.; Phoenixville, Chester co., Penn., 25 to 37 oz. The mines at all these localities have been abandoned.

GALENA, a city of Illinois, county seat of Jo Daviess co., and the centre of the region known as the "Galena lead mines," situated upon both sides of Galena river, 3 m. from its

junction with the Mississippi, 468 m. above St. Louis, and 406 below St. Anthony; lat. 42° 22′ N.; pop. in 1832, 1,000; in 1841, 2,225; in 1850, 6,004; in 1859, 14,000. The first house was built at Galena in 1819, the place at that time being known as La Pointe or Frederic's Point. In 1827 a village was laid out by Capt. Martin Thomas of the U. S. army, and named Galena, that being the name of the sulphuret of lead which abounds in the locality. In 1828 the first newspaper was established, entitled the "Miner's Journal," and in the same year the village comprised about 100 houses. The city has a high and healthy location, far enough removed from the Mississippi to be entirely free from the miasmatic exhalations of the river, and yet sufficiently near to enjoy all its commercial advantages. Galena river is always navigable for any steamboats that can ascend the rapids of the Mississippi. The ground upon which the city is built rises abruptly at a short distance from the river on both sides, and some of the bluffs reach a height of upward of 200 feet. These bluffs, which encircle the whole city, are composed of mountain limestone, and give the place an extremely irregular and picturesque appearance. In the environs are many streams of water, which afford ample power for manufacturing purposes. On these streams are 12 or 15 mills. The public and private buildings of Galena are mostly of brick, and many of them in a good style of architecture. There are 12 churches, 2 daily newspapers, 10 public school-houses with 1,500 scholars, a seminary, a U. S. marine hospital, and a custom house and post office built of stone at a cost of $70,000. There are 3 large steam saw mills, 1 large steam flouring mill, 2 lead furnaces, 2 iron founderies and machine shops, 2 extensive plough manufactories, 5 wagon shops, 2 large furniture manufactories operated by steam, 1 pottery, 8 lumber yards, 3 large leather furnishing houses, 3 soap and candle manufactories, 7 breweries, and 2 carriage manufactories. Two daily lines of steamboats run to St. Paul and St. Anthony, and intermediate points, and 2 daily lines to St. Louis; and there are 4 daily passenger and 2 freight trains of the Illinois central railroad. Galena is 8 hours from Chicago, 18 from St. Louis, 24 from Cincinnati, and 48 from New York. The steamboat tonnage owned there amounts to 4,962 tons, and there were 490 arrivals and departures of steamboats in 1857. The exports of lead in 1857 were valued at $801,324, while the value of horses, cattle, grain, flour, potatoes, pork, and bacon exported was $839,014. The total amount of lead shipped from the Galena mines from 1821 to 1858 was 820,622,839 pounds, the value of which was $32,824,913. The greatest amount in any one year was in 1845, when 54,494,850 pounds were shipped. In 1857 the amount shipped was 34,183,250 pounds.-The Galena mines will be described in the article LEAD.

GALERIUS, CAIUS VALERIUS MAXIMIANUS, & Roman emperor, reigned from A. D. 305 to 311.