a considerable distance from Athens, and its inhabitants were forbidden, under penalty of death, to enter the Athenian territories, he used to go to the city in disguise, in the evening, to enjoy the instruction of Socrates, and return at day-break. He afterwards deviated from the simple system of his teacher, and changed his plain irony into the most subtle disputation. With the Eleatics, he maintained that there was but one being in the universe; and this being he called the true and good. For its subtilty and disputativeness his school was also called the Eristic school. He died 424 B. C. Eubulides was one of his pupils.

EUDEMONISM, EUDEMONOLOGY; the doctrine of happiness, or that system which makes human happiness its prime object, the highest motive of every duty, and of a virtuous life, and consequently the whole foundation of morals. Eudæmonism is contradistinguished to that morality or pure system of philosophy, which makes virtue itself the chief object, independent of its tendency to promote human happiness. Eudæmonist; one who supports the doc

trine of Eudæmonism.

EUDIOMETER; an instrument for ascertaining the purity of air, or, rather, the quantity of oxygen contained in any given bulk of elastic fluid. Dr. Priestley's discovery of the great readiness with which nitrous gas combines with oxygen, and is precipitated in the form of nitric acid, was the basis upon which he constructed the first instrument of this kind. It consisted of a glass vessel, containing an ounce by measure. This was filled with the air to be examined, which was transferred from it to a jar, of an inch and a half diameter inverted in water; an equal measure of fresh nitrous gas was added to it, and the mixture was allowed to stand two minutes. If the absorption were very considerable, more nitrous gas was added, till all the oxygen appeared to be absorbed. The residual gas was then transferred into a glass tube, two feet long and one third of an inch wide, graduated to tenths and hundredths of an ounce measure; and thus the quantity of oxygen absorbed was measured by the diminution that had taken place. Other eudiometrical methods were employed by other chemists. Volta had recourse to the detonation of air with hydrogen gas. For this purpose, two measures of hydrogen gas are introduced into a graduated tube, with three of the air to be examined, and fired by the electric spark. The diminution of bulk observed after the vessel had returned to its original

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temperature, divided by three, gives the quantity of oxygen consumed. The action of liquor prepared from sulphur and potash, or sulphur and line, boiled in water, and the slow combustion of phosphorus, have, likewise, been employed in eudiometry. Dobereiner has suggested the use of little balls of spongy platina, for the purpose of detecting minute portions of oxygen in a gaseous mixture, in which hydrogen is also present. Its effect is immediate and complete. The moment the substance rises above the surface of the mercury, in the tube containing the mixture, the combination of the oxygen and hydrogen begins, and in a few minutes is completed. So energetic is it in its action, that it enables hydrogen to take 1 of oxygen from 99 of nitrogen-a result which it is impossible to obtain by electricity.

EVERGETE (benefactors). This name was given to a small nation, called Agriaspa or Arimaspi, in the Persian province of Drangiana, because they saved the elder Cyrus with his army in the desert, when in great distress for want of provisions. This little tribe had a good form of government, entirely different from that of the surrounding barbarians. Alexander, therefore, not only left them their constitution and liberties entire, but also granted them, at their request, some territories in their vicinity. Some princes have borne this name, e. g., the Ptolemies.

EUGENE, Francis, of Savoy, known as prince Eugene, fifth son of Eugene Maurice, duke of Savoy-Carignan, count of Soissons, and Olympia Mancini, a niece of cardinal Mazarin, was born at Paris, 1663. Among all the generals and statesmen of Austria, none has rendered more numerous and important services than Eugene. He was great alike in the field and the cabinet. Contrary to his own inclinations, Eugene was destined for the church. He petitioned Louis XIV for a company of dragoons, but was refused on account of the opposition of Louvois, minister of war, who hated the family of Eugene. Indignant at this repulse, and at the insults offered to his family, and particularly to his mother, Eugene, in 1683, entered the Austrian service, as two of his brothers had already done. He served his first campaign as a volunteer against the Turks, under two celebrated generals, Charles, duke of Lorraine, and Louis, prince of Baden, with so much distinction that he received a regiment of dragoons. Louvois, jealous of the reputation of Eugene, said angrily, "He shall never return to his country." Eugene, to whom

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these words were reported, replied, "I shall return in spite of Louvois;" and, in fact, some years afterwards, he entered France at the head of a victorious army. In 1687, after the battle of Mohacz, he was made lieutenant field-marshal. War having broken out between France and Austria, he prevailed upon the duke of Savoy to enter into an alliance with the emperor, and commanded the imperial forces sent for the defence of Savoy. He rejected the tempting offers made by France to engage him in her service, and was raised by the emperor to the rank of general field-marshal. After the war in Italy was concluded, he was sent to Hungary with the rank of commander-in-chief. He defeated the Turks at the battle of Zenta (September 11, 1697), and obtained, on that occasion, the applause of Europe, and the entire confidence of the imperial armies, although his enemies, envious of his glory, accused him of temerity, in undertaking so hazardous an enterprise. The loss of the Turks at Zenta obliged them to accede to the peace of Carlowitz, 1699, which was the first symptom of their decline. The Spanish war of succession next called Eugene to a new theatre of glory. Italy became the field in which he displayed his military talents. He advanced rapidly through the passes of the Tyrol, at the head of 30,000 men, in the face of marshal Catinat, who endeavored in vain to arrest his progress. Villeroi was still more unsuccessful, being surprised and defeated, near Cremona, by Eugene. In 1703, he received the command of the army in Germany; and, being appointed president of the council of war, he was the soul of all important enterprises, to which he imparted great activity; and his eilicient coöperation with Marlborough frustrated the plans of France and her allies. In the battle of Hochstädt (Blenheim, see Blenheim), August 13, 1704, the two heroes gained a decisive victory over the French and Bavarian army, commanded by the prince of Bavaria and marshal Tallard, the latter of whom was made prisoner. In 1705, Eugene returned to Italy, where he was severely wounded in an engagement with the French under the duke de Vendôme, and being obliged to retire from the field, his army was defeated; but Vendôme was recalled, and his successor, the duke de la Feuillade, could not withstand Eugene, who now hastened to the relief of Turin, stormed the French lines, forced them to raise the siege, and in one month drove them out of Italy. In 1707, he entered France, and laid siege to Toulon;

but the immense superiority of the enemy obliged him to retire into Italy. The following years he fought on the Rhine, took Lille, and defeated the marshals Villars and Boufflers at the battle of Malplaquet, where he himself was dangerously wounded. In this situation, he maintained that calmness peculiar to great souls: when the officers urged upon him the necessity of providing for his personal safety, "What need of bandages," said he, "if we are about to die here? If we escape, the evening will be time enough." After the recall of Marlborough, which Eugene opposed in person, at London, without success, and the defection of England from the alliance against France, his farther progress was in a great measure checked, more particularly after the defeat of general Albemarle at Denain. The peace of Rastadt, the consequence of the treaty of Utrecht, was concluded between Eugene and Villars in 1714. In the war with Turkey, in 1716, Eugene defeated two superior armies at Peterwaradin and Temesvar, and, in 1717, took Belgrade, after having gained a decisive victory over a third army that came to its relief. The treaty of Passarovitz was the result of this success. During fifteen years which followed, Austria enjoyed peace, and Eugene was as active in the cabinet as he had been in the field, when the Polish affairs, in 1733, became the source of a new war. Eugene appeared, in his old age, at the head of an army, on the banks of the Rhine, but returned to Vienna, without effecting any thing of importance. He died in 1736, at the age of 72. The Austrian department of war, to which he imparted such activity during his presidency, relapsed, after his death, into its former imbecility.

EUGENE DE BEAUHARNAIS, duke of Leuchtenberg, prince of Eichstedt, exviceroy of Italy, was born September 3, 1781. He was the son of the viscount Alexander Beauharnais (q. v.), who was guillotined 1794, and Joséphine Tascher de la Pagerie, afterwards wife of Napoleon and empress of France. During the French revolution, Eugene entered the military service, and, at the age of 12 years, accompanied his father, when he took the command of the army of the Rhine. After his father's death, he joined Hoche, in La Vendée, when his mother was in prison. After the 9th Thermidor, he returned to his mother at Paris, and remained three years devoted to study. In 1796, Joséphine was married to general Bonaparte, then commander-in-chief of the army of Italy; and Eugene accompanied his father

in-law in his campaigns in Italy and Egypt. He was promoted to a high rank in the service, and, in 1805, created a prince of France and viceroy of Italy. In the same year, he distinguished himself in the campaigns against Austria, and, after the peace of January 13, 1806, married the princess Augusta of Bavaria. In 1807, Napoleon made him prince of Venice, and declared him his heir to the kingdom of Italy. He administered the government of Italy with great prudence and moderation, and was much beloved by his subjects. In the war of 1809, he was at first unsuccessful against the archduke John, but soon afterwards gained the battle of Raab, and distinguished himself at Wagram. He conducted with great prudence on the occasion of the divorce of Napoleon from his mother. The 3d of March, 1810, Napoleon appointed him successor of the prince primate, who had been created grand-duke of Frankfort. In the Russian campaign, he commanded the third corps d'armée, and distinguished himself in the battles of Ostrowno, Mohilo, and that on the Moskwa (Borodino). In the disastrous retreat, he did not desert the wrecks of his division for a moment, but shared its toils and dangers with the soldiers, and encouraged them by his example. To him and to Ney, France was indebted for the preservation of the remains of her army during that fatal retreat. On the departure of Napoleon and Murat, he was left in the chief command, and showed great talent at that dangerous conjuncture. We find him again at the battle of Lützen, of May 2, 1813, where, by surrounding the right wing of the enemy, he decided the fate of the day. Napoleon sent him from Dresden to the defence of Italy, now menaced by the enemy's forces, where military operations commenced after the dissolution of the congress of Prague, and the accession of Austria to the league of the allied powers. Eugene maintained the defence of Italy even after the desertion of Murat. After the fall of Napoleon, he concluded an armistice with count Bellegarde, by which he delivered Lombardy, and all Upper Italy, to the Austrians. Eugene then went immediately to Paris, and thence to his father-in-law at Munich. He was at the congress of Vienna. On the return of Napoleon from Elba, he was obliged to leave Vienna, and retire to Baireuth. He was an inactive spectator of the events in 1815. By the articles of Fontainebleau, an indemnification was assigned him for the loss of his estates in

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Italy, which were valued at 20-25 millions of francs: but the congress of Vienna, confirmed his dotation in the march of Ancona, and the king of Naples was obliged to pay him 5 million francs. By an ordinance of the king of Bavaria, he was created duke of Leuchtenberg, November, 1817. The Bavarian principality of Eichstedt was bestowed upon him, and his posterity declared capable of inheriting in case of the failure of the Bavarian line. He died at Munich, Feb. 21, 1824, leaving two sons and four daughters. Prince Eugene, under a simple exterior, concealed a noble character, and great talents. Honor, integrity, humanity, and love of order and justice, were the principal traits of his character. Wise in the council, undaunted in the field, and moderate in the exercise of power, he never appeared greater than in the midst of reverses; as the events of 18131814 prove. He was inaccessible to the spirit of party, benevolent and beneficent, and more devoted to the good of others than his own. He died of an organic disorder of the brain. (See Vie politique et militaire d'Eugène Beauharnais, Vice-roi d'Italie, by Aubriet, second edition, Paris, 1825.) His sister is the duchess of SaintLeu, Hortensia Eugenia, wife of Louis Bonaparte, former king of Holland, but lives separate from her husband. His son, the duke Augustus, who succeeded him, was born Oct. 10, 1810. His eldest daughter, Joséphine, was married 23d of March, 1823, to Oscar, crown-prince of Sweden, son of Charles XIV; his second daughter, Hortensia Eugenia, was married to the prince of Hohenzollern-Hechingen, in 1826. Amalia Eugenia married the emperor of Brazil, in 1829.

EULENSPIEGEL, Tyll, was born at Kneitlingen, a village of Wolfenbüttel, not far from Schöppenstädt, and died, about 1350, in the little town of Möllen, about 18 miles from Lubec, where his gravestone, with a looking-glass (spiegel) and an owl (cule) upon it, in allusion to his name, yet stands. His name has become proverbial in Germany for all sorts of wild, whimsical frolics, which are committed from pure love of fun; for Tyll was continually engaged in such, as he roved about through Lower Saxony and Westphalia, and even as far as Poland and Rome. Accounts of them are still preserved in the popular traditions of Germany. At what time and in what language they were first committed to writing can hardly be determined. From the title of the old popular editions, it would seem to have

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been in Low-German, and it has been supposed, without sufficient evidence, that Thomas Murner, the Franciscan, doctor of theology and law, and an antagonist of Luther, known by his Fool's Complaint, and other writings of a similar stamp, translated them into High-German. Indecencies are frequently to be found in the book, but they belong to the age. It has been a favorite book, not only with the German, but many other nations, has been translated into English, French, Latin, Dutch and Polish, has been often imitated, and has passed through editions without number. (See Reichard's Bibliothek der Romane, vol. 2 and 4; Flögel's Geschichte der Hofnarren, and Görres' Ueber die Volksbücher.) The earliest printed edition, as far as can be ascertained, is the High German, Strasburg, 1519, 4to. A very rare engraving by Luke of Leyden is called the Eulenspiegel (l'Espiègle).

EULER, Leonard; a mathematician, born at Bâle, 1707, learned from his father, a clergyman, the first rudiments of the science in which he was afterwards so distinguished. At the university of Bale he enjoyed the instructions of John Bernouilli, and the friendship of Daniel and Nicholas Bernouilli, who successfully emulated their father's fame. In his 19th year, he gained the accessit of the prize offered by the Paris academy of sciences for the best treatise on the masting of vessels. Catherine I, desirous of completing the establishment of the academy of Petersburg, invited Daniel and Nicholas Bernouilli thither. Nicholas died, and Daniel soon returned to his native country, after having procured a place in the academy for his friend Euler. Euler now constituted the whole mathematical department in the academy, and labored with astonishing industry; he composed more than half of the treatises in this branch of science contained in the 46 quarto vols. published by the academy, from 1727 to 1783, and, at his death, left about 100 unpublished dissertations, which were successively printed by the society. To the Paris academy of sciences he also presented several treatises (among the rest, his dissertation Inquisitio phys. in Causam Fluxus ac Refluxus Maris, which gained the prize, though Bernouilli and Maclaurin were among his competitors), and carried off or divided 10 prizes. In 1741, he accepted an invitation from Frederic the Great to become professor of mathematics in the Berlin academy, but, in 1766, returned to Petersburg, where he died in 1783, in the office of director of the mathe

matical class of the academy. He receiv ed from all parts of Europe flattering marks of respect. The academy of sciences in France chose him, in 1775, one of its foreign members, though none of those places, then so much an object of ambition, was vacant. He also received considerable presents for the assistance which he rendered to Tob. Mayer (q. v.) in preparing his lunar tables, and £300 sterling, as his share of the prize offered by the English parliament for the best method of determining the longitude at sea. He distinguished himself, particularly, by his endeavors to perfect the analytic method, according to the system of Bernouilli, and the Leibnitzian school, and to complete its separation from pure geometry, which Newton's disciples principally employed in their investigations. He first gave the example of those long processes, in which the conditions of the problem arc first expressed by algebraic symbols, and then pure calculation resolves all the difficulties. In this, Euler displayed extraordinary acuteness, and a profound as well as inventive genius. He gave a new form to the science. He applied the analytic method to mechanics, and enlarged the boundaries of this science. He greatly improved the integral and differential calculus (q. v.), of which he afterwards published a complete course, which surpassed every thing then extant on this subject. His first essay, On the Masting of Vessels, and still more his residence at Petersburg, undoubtedly led him to the application of mathematics to the building and management of vessels; and he composed his Théorie compl. de la Construct. et de la Manauvre des Vaiss., which has been introduced into the French naval school, and translated into English, Italian and Russian. The great questions on the system of the universe, which Newton left to his successors to resolve, were the constant object of Euler's inquiries, and constitute the subjects of most of his prize essays. An extensive dioptric treatise, Sur la Perfection des Verres object. des Lunettes, in the Mémoires de Berlin, 1747, was the result of his inquiries into the means of improving spectacles. The share which he contributed, by this work, towards the discovery of achromatic telescopes, is sufficient to distinguish his name in this department also. But, in his treatises on physics, he often proposes untenable hypotheses, and appears only to be seeking opportunities for calculation. He also employed himself in metaphysical and philosophical speculations. He attempted to prove the im