JEAN BERNARD, an eminent philosopher, was born at Leichstall, in the canton of Bâle, in 1723. His father, who was a highly respected pastor in his native town, removed to Bâle, and was placed in 1738 at the head of the Protestant churches of the canton. The objects of study which attracted him most were poetry and philosophy; for he possessed in an almost equal degree a taste for philology and philosophy, for metaphysics and the fine arts. Having received his doctor's degree at the age of seventeen, he soon after entered the church, and distinguished himself as a preacher. After a short residence at Lausanne, which enabled him to perfect himself in the French language, Merian accepted the place of preceptor to the sons of a gentleman in Amsterdam, where he spent four years. In 1748 he received from Maupertuis, president of the Academy of Berlin, an invitation to attach himself to that learned body, with the offer of a pension from Frederick II. Merian did not hesitate to respond to this flattering proposal, but came immediately to Berlin, where, during more than half a century, he exerted a most salutary influence not only over the Academy of Sciences, but over public instruction in general in Prussia. He enriched the philosophical literature of the academy by a series of memoirs on some of the most important problems in morals and metaphysics, and which are generally regarded as masterpieces of clearness and impartiality. On the death of Forney, whose éloge he pronounced in 1797, Merian was appointed perpetual secretary to the academy. He died on the 12th of February 1807, lamented by many of the greatest names in Europe, with whom he had been long associated, such as Euler, Lagrange, Sulzer, Lambert, Ancillon, &c.

At the request of Frederick II. Merian translated Clanchan's "Endeckung de Proserpina;" and afterwards published the "Essais Philosophiques" of David Hume, and the "Lettres Cosmologiques" of Lambert. In his philosophical memoirs his main object is to combat the philosophy of Leibnitz. These will be found in the Memoirs of the Academy of Berlin, extending over a period of upwards of forty years, from 1749 to 1804. (For farther information respecting Merian, see the "Histoire de la Philosophe Moderne" of Victor Cousin, vol. i., first series; and the "Dictionnaire des Sciences Philosophiques," Paris, 1849.)

Merian, Matthew, an eminent painter, was the son of a distinguished engraver of the same name, and was born at Bâle in 1621. After studying under his father and Sandrart, he travelled to complete his education in his art, and became intimate with Vandyck and Rubens in England, with Voget and Lesueur in France, with Sacchi and Maratti in Italy, and with Jordaens in the Netherlands. He settled first at Nuremberg, and afterwards at Frankfort-on-the-Main. In the latter city he painted, after the style of his master Vandyck, the portraits of the Emperor Leopold I. and several other German princes. These works were rewarded with both money and honours. Yet at the same time Merian conducted the trade in books and prints which his father had left him. He died at Frankfort in 1687.

Merian, Maria Sibylla, a skilful drawer of insects and other subjects of natural history, was the sister of the preceding, and was born at Frankfort-on-the-Main in 1647. She was instructed in drawing by Morell, her step-father, and Abraham Mignon, and soon displayed a notable taste and truthfulness in her sketches of flowers, butterflies, and caterpillars. In 1665 she was married to John Andrier Graff, a painter of Nuremberg, but was still known by her maiden name. Her studies and her scientific excursions were not interrupted, and the first result of her labours was published in 1679-83, under the title of "The Origin of Caterpillars, their Nourishment and Changes," in 2 vols. folio, Nuremberg. A Latin translation of this work appeared in Amsterdam in 1717. In 1684 she and her husband were induced by offers of patronage to settle in Holland. Maria Sibylla's enthusiasm for her art increased with her years. In 1699 she crossed the Atlantic with no attendant but her daughter, and spent two years at Surinam in sketching the insects, shells, and plants of the new world. A part of these sketches was published in her "Dissertatio de Generatione et Metamorphosis Insectorum Surinamensium," Amsterdam, 1705. Maria Sibylla Merian died in 1717. A new edition of her last work was published soon after her death, with twelve plates by her two daughters. Her former work, enlarged by herself and her daughters, was published in French by John Marret, under the title of "Histoire Générale des Insectes de l'Europe," folio, Amsterdam, 1730. These two corrected works were published together under the common title of "Histoire des Insectes de l'Europe et de l'Amérique," folio, Paris, 1786-71.