Euler's knowledge was not limited to mathematics and the physical sciences. He had carefully studied ana tomy, chemistry, and botany, and he was also deeply ver sed in ancient literature. He could repeat the eEneid from the beginning to the end, and he could even tell the first and last lines in every page of the edition which he used. lu one of his works there is a learned memoir on a question in mechanics, of which, as he himself in forms us, a verse of Lucid gave him the first idea.
Euler possessed naturally a strong constitution; and when we consider the nature of his studies, and the as siduity %%nil which he pursued them, we cannot fail to be surprised at the great degree of health which he en joyed. In all his habits he was sober and temparatc, in his manners unaffected and pleasing, and in his temper lively and cheerful. In his moral and religious charac ter there is much to admire. The high fame which he acquired, and the interruptions which he must have ex perienced both at Berlin and St Petersburg, never induced him to abandon the religious duties to which he had been educated. As long as lie preserved his sight, he assem bled the whole of his family every evening, and read a chapter of the Bible, which he accompanied with an ex hortation. Theology was one of his favourite studies, and his doctrines were the must rigid doctrines of Cal vinism, the only s) stem of religious truth which a phi losonher can maintain.
The following is a list of the principal works which Euler published in a separate form. His papers, which appeared in the Memoirs of the Academics of Berlin and St Petersburg, are extremely numerous; and he left be hind him no fewer than 200 ready for publication, in or der to fulfil a promise iv 111C h lie had made to Count Or loff, to supply memoirs for the 4eta Petro/zolitana for 20 years alter his death.
Dissertatio Physica de Sono. Basle, 1727.
Mechanica sive mitts scientia analytiee ex/zosita. Pc tropoli, 1736, 2 vols.
Tentamen nova theories. musics. Petrol). 1739. This work contains many new views ; but as M. Fuss re marks, it had no great success, as it contained too much geometry for musicians, and to much music for geome ters.
Methodus inveniendi lineas curves minimive firoprietate gaudentes. Lausanne:, 1744, 4to.
Introductio in ilnalysin liVnitorum. Lausanne. 1744, 2 vols. 4to. This work, which had become very scarce, was reprinted at Lyons in 1797. It was translated into French in 1796, by J. 13. Labey, and published at Paris.
Theoria 7710iIntill planetarum et cometarum. Bey()hill, 1744.
Opuscula varii argumenti. Berolini, 1746, 1750, 1751, 3 vols. in 4to. The tables of the sun and moon, which are sometimes to be found separately, form part of the 1st volume of this collection. As the three vo lumes make only 600 pages, they are generally found in one.
Scientia navalis, sett tractatus de construcndis ac diri gendis navibus Pet•opoli, 1749, 2 vols. 4to.
Theoria motuum Luna.. exhibens C11172C8 corporum ine qualitatcs cum adcloanielao. 13erolini, 1753, 4to.
Disscrtatio de principio ?liberate actionis, una cum ex amine objection urn Cl. Koenigii, contra hoc principium factarum. Berolini, 1753, 4to.
Institutiones calculi differentialis, coin ejus mu in ana lysi ac doctrine sericrum. tier°lini, 1755. Another edition of this work was published in 1787, in 2 vols. 4to, and another at St Petersburg in 1804, in 2 vols. 41o.
Constructio lentium objectivarum ex duplici vitro. Pe trol). 1762.
Meditationes de perturbatione motus cometarum ab at tractione planmarum circa. Petrop. 1762, 4to.
Theoria motus corporum solidorum see rigidorum. Rostochii, 1765, 410.
Insatutiones Calculi Integralis. Petrop 1768-1770, 3 vols. 4to. Another eclitioh, more correct, was pub lished at Petersburg in 1792 and 1794, in 4 vols. 4to.
Diolarica. Petrop. 1769, 1771, 3 vols. quarto.
Nova' Tabu16c Lunares singulari methodo construct Petrop. 1772, 8vo.
Opuscula fJrsalyrica, Petrop. 1783. 1785, 2 vols. 4to.
Lettres a une Princesse d'Alleniagne stir quelques so jets de Physique et de Philosophic. Petersburg, 1768, 1772, 3 vols. 8vo. Another edition of this was pub lished at Berne in 1778, in 3 vols. 8vo. An edition was published in Paris, with notes by Condorcet, and ano ther in 1812, by J. B. Lobey.
d'illgebre trail. de 1'Allemand, par J. Ber noulli, avec des notes par Lagrange et Gamier. Paris, 1807, 2 vols. 8vo. Two editions of this work were published at Lyons in 1774, and 1796, and an edition appeared in London translated into English.
Theorie complete de la construction et de la mana'uvre des vaisseaux, (le style retouclie par Kerano.) Pat s 1776, 8vo. The original edition of this work appeared at St Petersburg in 1773.
A collection of the best productions of Euler appear ed at Brienne in 1797, in 18 volumes.
A more extended list of the writings of this illus trious mathematician, will be found in his Eloge by Nicholas Fuss, which was published at St Petersburg, in 1783, in 4to. (A)