During the eighteenth century the names of a pleiad of women of wide culture stood out in France, whose halls were frequented by famous writers and artists. However, little is known about a single case, that of Gabrielle-Emile le Tonnelier Breteuil (1706 - 1749), Marchioness of Châtelet, translator, from English into French, of the work of the English physicist Sir Isaac Newton (1642 - 1727).
The Marchioness of Châtelet was born in Paris on December 17, 1706, three centuries ago. Her parents were Louis Nicolas Tonnelier, Baron Preuilly, favorite of King Louis XIV of France, and Anne de Froullay. His father noted her great intellect and surrounded her with mentors and tutors in all subjects, including what was her passion: mathematics. At Versailles, Gabrielle-Emile''s mental agility caused an impression, which allowed her to earn easy money in the gambling tables, which then she invested in books for her extensive library. At 19 she married Claude Florent Châtelet, a member of an ancient noble family. It was a marriage of convenience, a common practice at that time. The Marquis and the Marquise did each their own ways. She in court and he commanding his regiment. Enjoying this great freedom, Gabrielle-Emile fell in love with Voltaire, whom she knew time ago from the meetings at her parents''. This relationship lasted fifteen years and its onset was recorded in these verses of the great Frenchman writer: "Why did you come to me so late in my life? / What have I done with my life so far?/I searched for love/And I''ve only seen mirages ..."
So they decided to retire to Castle Cirey-sur-Blaise, and founded what today might be considered the first science studies center in the world. By then, the Marchioness was already recognized for her work on natural philosophy - that was the name of what we currently call physical sciences - among which a study on nature and spread of fire excelled (1738), and a treatise entitled "Physics Institutions"(1740), where she made a lucid analysis of the work of the German rationalist philosopher Gottfried Wilhelm Leibniz (1646 - 1716). Both characters, the Marchioness and Voltaire, admired the work of the English physicist Sir Isaac Newton (1642 - 1727) on the order of cosmos, but from different points of view. She, pure scientist, took Newton''s ideas for her studies on energy conservation and the nature of light. Voltaire, on his part, was seeking to move the rational laws of cosmos to political order. When the romance between the two was over, a great mutual respect and affection remained. Thus, when Voltaire wrote a preface to the Marchioness'' posthumous work, the French translation of "Elements of Newton''s Philosophy," published ten years after her author''s death, in 1749, he wrote: "This book contains wonders. The first is that Newton was able to perform this great work. The second is that a woman was able to translate and explain it lucidly". This book is still considered the most successful version in French of the famous English scientist''s work.
But, what self-image did the Marquise de Châtelet have? A letter to King Frederick "The Great" of Prussia reveals it: "Judge me by my own merits, or lack of them, not because I am the appendix of a great general or of a distinguished scholar, a bright star in the French court or, by itself, in the literary world. I am a responsible person in front of myself, for who I am, what I say and do. There may be greater metaphysicians and philosophers than me, whom I have not known yet. They are also human beings, and therefore defective. Thus, I add up all my gifts and I confess that I do not feel inferior to anyone".
Gabrielle-Emile Breleiul Tonnelier died in Luneville, Lorraine, September 10, 1749, from childbirth complications after giving birth to her fourth child, the fruit of her relationship with her last lover, the poet François Saint-Lambert. A few days earlier she had finished her immortal translation. Until the end of his days Voltaire would say that only she had the ability to describe the more complex aspects of cosmos with mathematical precision. The German philosopher Emmanuel Kant also did a great compliment to her figure. However, during the nineteenth century her name was erased from the annals of science. Her rehabilitation began in the early thirties of last century, and continues to this day. Currently there is no longer the gender gap in science, a fact whose justice can be attributed to major figures like Gabriell-Emile le Tonnelier Breteiul, Marquise de Châtelet.