for his discovery of the curve called the conchoid, or con chiles.

DIONYSIUS, surnamed PERIEGETES, a learned geographer, to whom is attributed a Periegesis, or Survey of the Earth, in Greek verse. Some suppose that he lived in the time of Augustus; but Scaliger and Saumasius place him under the reign of Severus, or Marcus Aurelius. He wrote many other works, but his Periegesis is the only one we have remaining; the best and most useful edition of which is that improved with notes and illustrated by Hill.

MEDICINE.

CLAUDIUS GALEN, prince of the Greek physicians after Hippocrates, was born at Pergamus, in Asia Minor, A. D. 131. His father being possessed of a fortune, and well versed in philosophy, astronomy, geometry, and architecture, instructed his son in the first rudiments of learning, and afterwards procured him the greatest masters of the age. Galen, having finished his studies, chose physic for his profession, studied the works of Hippocrates, and at length resolved to travel, to converse with the most able physicians in all parts, and to take every opportunity of inspecting on the spot the plants and drugs of the countries through which he passed. With this view he went to Alexandria where he stayed some years; thence he travelled through Cilicia, Palestine, Crete, Cyprus, Lemnos and the Lower Syria; in which last place he obtained a thorough insight into the nature of the Lemnian earth, and the opobalsamum; after which he returned home by Alexandria. Galen had been four years at Pergamus, where his practice was attended with extraordinary applause, when some commotions induced him to go to Rome, where he resolved to settle; but the proofs he gave of his superior skill, added to the respect shown him by several persons of very high rank, created him so many enemies among his brethren of the faculty, that he was obliged to quit Rome, after having resided there four or five years. He had not long returned to Pergamus, when he was recalled by the emperors Aurelius and Verus. After their death, he retired to his native country, where he died about A. D. 200. He wrote in Greek; and is said to have composed two hundred volumes, the greater part of which were unhappily burnt in the temple of Peace. Galen was of a weak and delicate constitution, as he himself asserts; but he nevertheless by his temperance and skill in physic, arrived to a great age. One of his rules was always to rise from table with some degree of appetite. He is justly considered as the greatest physician of antiquity, next to Hippocrates; and he performed such sur

prising cures, that he was accused of magic. Several of his works are still extant; of which the Greek editions are those of Aldus, Venice, 1525, 5 vols, fol. ; and Basil, 1538: the Latin are that of Paris, 1536, fol.; Lyons, 1554; Basil, 1542: but the best are that of Venice, in 1609; and that of Paris, in Greek and Latin by Chartier. He wrote in an elegant style, but rather diffuse. He shows himself well acquainted with philosophy and general science, and deserves to be reckoned one of the most universal scholars of antiquity.

ÆLIANUS MECCIUS, a physician mentioned with respect by Galen. He was the first who made use of treacle against the plague, and found it to succeed.

QUINTUS SERENUS SAMONICUS, a learned man in the reigns of Severus and Caracalla, is usually reckoned among the physicians, though neither his condition in life, nor his country is ascertained. He was the author of several works on learned topics, some of which are cited by Macrobius and other writers, but the only one preserved in our times is a poem or rather a work in verse, entitled "Carmen de Medicina," treating in hexameters of no very elegant construction, on the whole of medicine from the head to the feet, but in a manner empirical, with much fabulous and superstitious matter. He was greatly beloved by Geta, who was accustomed frequently to read his books addressed to Caracalla. But by the latter imperial monster Samonicus was murdered at a festival, perhaps on account of his attachment to Geta. He left a copious library to his son, who was also a learned man, and preceptor to the younger Gordian, to whom he bequeathed the library at his death. Of the poems of Samonicus, several editions have been printed, of which the most elaborate is that of Keuchenius, Amst. 1662. Burmann has also given philological and critical notes upon it in his Poëtæ Lat. Minores.

PERIOD XVIII.

FROM M. A. GORDIAN III. TO CONSTANTINE II.

[CENT. III.]

REMARKABLE FACTS, EVENTS, AND DISCOVERIES.

A.D.

203 The first persecution under Severus.

209 Severus's wall in Britain built.

222 The Roman empire begins to decline, and the Barbarians begin their irruptions, though bravely opposed by Alexander.

225 Mathematicians allowed to teach publicly at Rome.

236 The sixth persecution under Maximinus.

241 The Franks first mentioned in history.

250 The seventh persecution under Decius.

252 The eighth persecution under Gallus, who first bought a peace from the Goths and agreed to pay them annual tribute.

253 Europe ravaged by the Scythians and Goths.

258 The ninth persecution under Valerian.

200 Valerian taken prisoner by Sapor, king of Persia, and flayed alive. The Scythians ravage the Roman Empire.

273 Palmyra taken by the Romans.

277 The Franks settle in Gaul.

284 The Dioclesian era commenced August 29th or September 17th. 287 Carausius proclaimed emperor of Britain.

291 The emperors Dioclesian, and Maximian, and the two Cæsars, Constantius and Galeria, march to defend the four quarters of the empire.

297 Alexandria destroyed by Dioclesian.

THE vast empire of the Romans still continued to decline. In 260 the defeat and captivity of the emperor Valerian by the Persians, with the disturbances that followed, threatened the empire with utter destruction. Thirty tyrants seized the government at once, and the barbarians pouring in on all sides in prodigious numbers, ravaged almost all the provinces in the empire. By the vigorous conduct of Claudius II., Aurelius, Tacitus, Probus, and Carus, the empire was restored to its former lustre; but as the barbarians were only repulsed, and never thoroughly subdued, this proved only a temporary relief. What was worse, the Roman soldiers, grown impatient of restraint, commonly murdered those emperors who attempted to revive among them the ancient military discipline, which alone could ensure the victory over their enemies. Under Dioclesian, the disorders were so great, that though the government was held by two persons, they

found themselves unable to bear the weight of it, and therefore took other two partners in the empire. Thus was the Roman empire divided into four parts; which by all historians is said to have been productive of the greatest mischiefs. As each of the four sovereigns would have as many officers both civil and military, and the same number of forces that had been maintained by the state when governed only by one emperor, the people were not able to pay the sums necessary for supporting them. Hence the taxes and imposts were increased beyond measure, the inhabitants in several provinces reduced to beggary, and the land left untilled for want of hands. An end was put to these evils when the empire was again united under Constantine the Great; but in 330, a mortal blow was given to it, by his removing the imperial seat to Constantinople, and making it equal to Rome. His establishment of Christianity, now corrupted with the grossest superstitions, proved also no small detriment to the empire. Instead of that ferocious and obstinate valour in which the Romans had so long been accustomed to put their trust, they now imagined themselves secured by signs of the cross, and other superstitious symbols and unmeaning ceremonies. These they used as a kind of magical incantations, which of course proved at all times ineffectual; and hence also in some measure proceeded the great revolution which took place.

GOVERNMENT.

ROME.

MÆCINUS ANTONIUS GORDIAN III., grandson of Gordian I., was but twelve years old when he was honoured with the title of Cæsar. He was proclaimed emperor in the sixteenth year of his age, and his election was attended with universal marks of approbation. In the eighteenth year of his age, he married Furia Sabina Tranquillina, daughter of Misitheus, a man celebrated for his eloquence and public virtues. Misitheus was entrusted with the most important offices of the state by the son-in-law; and his administration proved how deserving he was of the confidence and affection of his imperial master. He corrected the various abuses which prevailed in the state, and restored the ancient discipline among the soldiers. By his prudence and political sagacity, all the chief towns in the empire were stored with provisions, which could maintain the emperor and a large army during fifteen days upon any emergency. Gordian was not less active than his father-in-law, and when Sapor, the king of Persia, had invaded the Roman provinces in the east, he boldly marched to meet him, and in his way defeated a large body of Goths, in Moesia. He conquered Sapor, and took many flourishing cities in the east from his adversary. In this success the senate decreed him a triumph, and saluted Misitheus as the guardian of the republic. Gordian

was assassinated in the east, A.D. 244, by the means of Philip, who had succeeded to the virtuous Misitheus, and who usurped the sovereign power by murdering the warlike and amiable prince. The senate, sensible of his merit, honoured him with a most splendid funeral on the confines of Persia, and ordered that the descendants of the Gordians should ever be free, at Rome, from all the heavy taxes and burdens of the state. During the reign of Gordian, there was an uncommon eclipse of the sun, in which the stars appeared in the middle of the day.

PHILIP, a Roman emperor, was an Arab, born at Bostra, in the Trachonitis, and the son, it is said, of a captain of robbers, which circumstance, however, does not argue him to have been of base extraction, but rather, as an Arabian, the_contrary. From the lowest rank in the Roman army he gradually rose to the highest offices; and when he was made general of the prætorian guards he assassinated Gordian to make himself emperor. To secure himself on the throne he left Mesopotamia a prey to the continual invasions of the Persians, and hurried to Rome, where his election was approved by the senate and people. Philip rendered his cause popular by his liberality and profusion, particularly on occasion of the centenary commemoration of the foundation of the city, which was celebrated with more magnificence than under the preceding reigns. His usurpation, however, was short. Philip was defeated by Decius, who had proclaimed himself emperor in Pannonia; and he was assassinated by his own soldiers near Verona, in the forty-fifth year of his age, and the fifth of his reign. His son, who had shared with him the imperial dignity, was also massacred in the arms of his mother. Young Philip was then in the twelfth year of his age, and the Romans lamented in him the loss of rising talents, of natural humanity, and endearing virtue. It has been a subject of controversy whether or not Philip was a Christian. He was certainly a protector of the new faith, and manifested great respect for its ministers. Origen addressed several epistles to him, his wife, and mother, which are not preserved. It is not improbable that the latter might be secret converts.

TITUS JULIUS PACATIANUS, a usurper, who excited the Gauls to revolt in his favour in the reign of the emperor Philip; but he was defeated and put to death, A. D. 249, by the troops which raised Decius to the throne. There are medals. of Pacatianus existing.

DECIUS, a Roman emperor, was born in Pannonia. The emperor, Philip, sent him to quell a sedition in Moesia, but instead of obeying his directions he turned his arms against him, and on his death assumed the imperial diadem. The activity and wisdom of Decius in some measure stopped the hastening decline of the Roman empire. The senate seemed to think so highly