CHASTELLET, GABRIELLE-EMILIE LE TONNELIER DE BRETEUIL, MARQUISE DU, the translator of Newton into French, was the daughter of Baron de Breteuil, aud was born iu 1706. In what manner the was led to study mathematics is not stated; the also became a proficient in Latin, English (in which Voltairo, as he tells us, was her instructor). and Italian. Sho was married very early to the Marquis du Chastellet-Lomont, a lieutenant-general of a dia. tinguished family of Lorraine. In 1733 she retired to the castle of Cirey, on the borders of Champagne and Lorraine, where the pursued her etudiee for several years. She died August 10, 1749, her death having bean hastened by close application to her translation of Newton. She died in the palace of Luneville, at the court of Stanislas, where her husband filled the office of high steward, and where Voltaire also was then residing. Her liaison (as the French call it) with Voltaire furnished sundry anecdotes for the scandalous chronicles of her day. The state of manners however, and iu particular the light in which the marriage contract was regarded among the French, are too well known to require any comment.
In 1738 Madame du Chaatellet wrote, for the prize of the Academy of Sciences, on the nature of fire. In 1740 the published at Paris her Institutions de Physique,' addressed to her eon, and a second edition appeared at Amsterdam in 1742. This work is a series of letters, in which the systems of Leibnitz and of Newton (the latter then almost new in France) are explained in a familiar style, and with a degree of knowledge of the history of the several opinions, and of sound language and ideas in their discuesion, which we read with surprise, remembering that they were the production of a French woman thirty years of age, written very few years after the introduction of the Newtonian philosophy into France. She takes that inter mediate view between the refusal to admit the hypothesis of attraction, and tLe assertion of it as a primary quality of matter, from which very few who consider the subject would now dissent. At the end
of this work is an epistolary discussion with M. de Moira; on the principle of "vie viva," the metaphysical part of which then created much controversy.
The translation of Newton wag published at Paris in 1759, with a "preface historique," and an dloge in verse by Voltaire, who probably owed to Madame du Chastellet the smattering of knowledge upon which he wrote his Elemens de la Philosophic de Newton,' published in 1738. From it we learn that the translation was submitted to the revision of Clairaut, who was the instructor of the authoress in mathematics. To the work is added a commentary, which beam tho name of Clairaut, being in faot his lessons committed to writing and arranged by Madame du Chastellet, and afterwards revised by their author. We here find, 1, a popular account of Newton's system; 2, investigations of various points by the analysis of the continental school, to the exclusion of the geometry of Newton ; 3, an abridg meat of Clairant's work on the figure of the earth ; 4, another of Daniel Bensouillis essay on the tide's. The translation itself is • close copy of the original In form and matter, hut does not profess to be perfectly literal, where the Laths is concise or obecure. It was used by ISelanibre in his citations (' Hist. d'Astron.,' avid. sibele), expressly that ha might have the unction of Clairaut in his versions of Newton. In 1806 this oorrespondence of Madame du Chastellet with the Count d'Argental was published at Paris, to which was appended a life, and a treatise 'Sur In Bonheur: (Biog. Voir. ; illsaairst peer serrir d /a Vie de Volleire, )ekle par faiselne; ft Pie de Volieurt, per Condoreet)