Born Gabrielle Émilie le Tonnelier de Breteuil, she was the
daughter of Louis-Charles-Auguste le Tonnelier de Breteuil, the
Principal Secretary and Introducer of Ambassadors to Louis XIV.
His position made him the center of social activity in the court,
and thus gave the family great status. Her mother, Gabrielle Anne
de Froulay, was brought up in a convent.
de Breteuil was a rather awkward child, and so she was given lessons
in fencing, riding, and gymnastics in an attempt to improve her
coordination. She was remarkably well educated for the time, and
by the age of twelve she was fluent in Latin, Italian, Greek and
German. She received education in mathematics, literature, and
even science as well. She also liked to dance, was a passable
performer on the harpsichord, sang opera, and was an amateur actress.
Émilie de Breteuil was married on 20 June 1725 to the Marquis
Florent-Claude du Chastellet, and thus became Marquise du Chastellet
(the spelling Châtelet was introduced by Voltaire, and has
now become standard). The Marquis was a military man and governor
of Semur-en-Auxois in Burgundy. The marriage was arranged, and
they had little in common, but did not openly fight often. Émilie
du Châtelet had three children, and, considering her marital
responsibility completed, they agreed to live separate lives.
In the upper classes of France at the time, it was standard for
both the husband and wife to have a lover.
du Châtelet had had three love affairs before she met Voltaire.
At the age of twenty-four, she had an affair with the Duc de Richelieu
that lasted for a year and a half. The Duc was interested in literature
and philosophy, and Châtelet was one of the few women who
could converse with him on his own level. She read every book
of consequence, attended the theater regularly, and enjoyed intellectual
debate. Châtelet expressed an interest in Isaac Newton,
and Richelieu encouraged her to take lessons in higher mathematics
to better understand his theories.
invited Voltaire to live in her country house at Cirey in Lorraine,
and she became his long-time companion (under the eyes of her
tolerant husband). There she studied physics and mathematics and
published scientific articles and translations. Her translation
of Newton's Principia Mathematica is still regarded as the standard
version in France. Her greatest discovery was the demonstration
that the kinetic energy of an object is a function of the square
of its velocity.
de Maupertuis, a member of the Academy of Sciences, became Châtelet's
tutor in geometry. He was a mathematician, astronomer and physicist,
and supported Newton's theories, which were the topic of hot debate
at the Academy.
last affair proved to be fatal. In her early 40s, she had an affair
with a young soldier and became pregnant. Fraught with premonitions
of dying in childbirth, Châtelet bore the child, but died
six days later from an embolism at the age of 43. A great mind
of the 18th century was prematurely lost.