practical schools of Alexandria, the true origin of science. We trace back all our exact knowledge to the Macedonian campaigns. Humboldt has well observed, that an introduction to new and grand objects of Nature enlarges the human mind. The soldiers of Alexander and the hosts of his camp-followers encountered at every march unexpected and picturesque scenery. Of all men, the Greeks were the most observant, the most readily and profoundly impressed. Here there were interminable sandy plains, there mountains whose peaks were lost above the clouds. In the deserts were mirages, on the hill-sides shadows of fleeting clouds sweeping over the forests. They were in a land of amber-colored date-palms and cypresses, of tamarisks, green myrtles, and oleanders. At Arbela they had fought against Indian elephants; in the thickets of the Caspian they had roused from his lair the lurking royal tiger. They had seen animals which, compared with those of Europe, were not only strange, but colossal-the rhinoceros, the hippopotamus, the camel, the crocodiles of the Nile and the Ganges. They had encountered men of many complexions and many costumes: the swarthy Syrian, the olive-colored Persian, the black African. Even of Alexander himself it is related that on his death-bed he caused his admiral, Nearchus, to sit by his side, and found consolation in listening to the adventures of that sailor-the story of his voyage from the Indus up the Persian Gulf. The conqueror had seen with astonishment the ebbing and flowing of the tides. He had built ships for the exploration of the Caspian, supposing that it and the Black Sea might be gulfs of a great ocean, such as Nearchus had discovered the Persian and Red Seas to be. He had formed a resolution that his fleet should attempt the

circumnavigation of Africa, and come into the Mediterranean through the Pillars of Hercules-a feat which, it was affirmed, had once been accomplished by the Pharaohs.

Not only her greatest soldiers, but also her greatest philosophers, found in the conquered empire much that might excite the admiration of Greece. Callisthenes obtained in Babylon a series of Chaldean astronomical observations ranging back through 1,903 years; these he sent to Aristotle. Perhaps, since they were on burnt bricks, duplicates of them may be recovered by modern research in the clay libraries of the Assyrian kings. Ptolemy, the Egyptian astronomer, possessed a Babylonian record of eclipses, going back 747 years before our era. Long-continued and close observations were necessary, before some of these astronomical results that have reached our times could have been ascertained. Thus the Babylonians had fixed the length of a tropical year within twenty-five seconds of the truth; their estimate of the sidereal year was barely two minutes in excess. They had detected the precession of the equinoxes. They knew the causes of eclipses, and, by the aid of their cycle called Saros, could predict them. Their estimate of the value of that cycle, which is more than 6,585 days, was within nineteen and a half minutes of the truth.

Such facts furnish incontrovertible proof of the patience and skill with which astronomy had been cultivated in Mesopotamia, and that, with very inadequate instrumental means, it had reached no inconsiderable perfection. These old observers had made a catalogue of the stars, had divided the zodiac into twelve signs; they had parted the day into twelve hours, the night into twelve. They had, as Aristotle says, for a long time devoted themselves to observations of star-occulta

tions by the moon. They had correct views of the structure of the solar system, and knew the order of emplacement of the planets. They constructed sundials, clepsydras, astrolabes, gnomons.

Not without interest do we still look on specimens of their method of printing. Upon a revolving roller they engraved, in cuneiform letters, their records, and, running this over plastic clay formed into blocks, produced ineffaceable proofs. From their tile - libraries we are still to reap a literary and historical harvest. They were not without some knowledge of optics. The convex lens found at Nimroud shows that they were not unacquainted with magnifying instruments. arithmetic they had detected the value of position in the digits, though they missed the grand Indian invention of the cipher.

In

What a spectacle for the conquering Greeks, who, up to this time, had neither experimented nor observed! They had contented themselves with mere meditation and useless speculation.

But Greek intellectual development, due thus in part to a more extended view of Nature, was powerfully aided by the knowledge then acquired of the religion of the conquered country. The idolatry of Greece had always been a horror to Persia, who, in her invasions, had never failed to destroy the temples and insult the fanes of the bestial gods. The impunity with which these sacrileges had been perpetrated had made a profound impression, and did no little to undermine Hellenic faith. But now the worshiper of the vile Olympian divinities, whose obscene lives must have been shocking to every pious man, was brought in contact with a grand, a solemn, a consistent religious system, having its foundation on a philosophical basis. Persia,

as is the case with all empires of long duration, had passed through many changes of religion. She had followed the Monotheism of Zoroaster; had then accepted Dualism, and exchanged that for Magianism. At the time of the Macedonian expedition, she recognized one universal Intelligence, the Creator, Preserver, and Governor of all things, the most holy essence of truth, the giver of all good. He was not to be represented by any image, or any graven form. And, since, in every thing here below, we see the resultant of two opposing forces, under him were two coequal and coeternal principles, represented by the imagery of Light and Darkness. These principles are in never-ending conflict. The world is their battle-ground, man is their prize.

In the old legends of Dualism, the Evil Spirit was said to have sent a serpent to ruin the paradise which the Good Spirit had made. These legends became known to the Jews during their Babylonian captivity.

The existence of a principle of evil is the necessary incident of the existence of a principle of good, as a shadow is the necessary incident of the presence of light. In this manner could be explained the occurrence of evil in a world, the maker and ruler of which is supremely good. Each of the personified principles of light and darkness, Ormuzd and Ahriman, had his subordinate angels, his counselors, his armies. It is the duty of a good man to cultivate truth, purity, and industry. He may look forward, when this life is over, to a life in another world, and trust to a resurrection of the body, the immortality of the soul, and a conscious future existence.

In the later years of the empire, the principles of Magianism had gradually prevailed more and more over those of Zoroaster. Magianism was essentially a wor

ship of the elements. Of these, fire was considered as the most worthy representative of the Supreme Being. On altars erected, not in temples, but under the blue canopy of the sky, perpetual fires were kept burning, and the rising sun was regarded as the noblest object of human adoration. In the society of Asia, nothing is visible but the monarch; in the expanse of heaven, all objects vanish in presence of the sun.

Prematurely cut off in the midst of many great projects, Alexander died at Babylon before he had completed his thirty-third year (B. c. 323). There was a suspicion that he had been poisoned. His temper had become so unbridled, his passion so ferocious, that his generals and even his intimate friends lived in continual dread. Clitus, one of the latter, he in a moment of fury had stabbed to the heart. Callisthenes, the intermedium between himself and Aristotle, he had caused to be hanged, or, as was positively asserted by some who knew the facts, had had him put upon the rack and then crucified. It may have been in self-defense that the conspirators resolved on his assassination. surely it was a calumny to associate the name of Aristotle with this transaction. He would have rather borne the worst that Alexander could inflict, than have joined in the perpetration of so great a crime.

But

A scene of confusion and bloodshed lasting many years ensued, nor did it cease even after the Macedonian generals had divided the empire. Among its vicissitudes one incident mainly claims our attention. Ptolemy, who was a son of King Philip by Arsinoe, a beautiful concubine, and who in his boyhood had been driven into exile with Alexander, when they incurred their father's displeasure, who had been Alexander's com