沙特莱侯爵夫人Émilie du Châtelet

我们首先应该对沙特莱侯爵夫人的名字做一些说明。婚前她的名字是Gabrielle-沙特莱侯爵夫人 Le Tonnelier de Breteuil，家人称她为Gabrielle-沙特莱侯爵夫人，但后来伏尔泰和其他人简单地称她为沙特莱侯爵夫人。我们还应该注意到，她的丈夫是Chastellet侯爵，她的出版物以Madame la Marquis du Chastellet的名字出现。拼写“沙特莱侯爵夫人”是由伏尔泰引入的，现在已成为标准。在这部传记中，我们将称她为“沙特莱侯爵夫人”直到她结婚，此后称为“沙特莱侯爵夫人”。

沙特莱侯爵夫人的父亲是Louis Nicolas Le Tonnelier de Breteuil。他是凡尔赛路易十四宫廷的官员，在巴黎有房产，在图赖讷也有土地。他被不同地描述（[6]和[8]）为：-

...年轻时是个迷人的人...时髦但有点可笑...没有人很喜欢他...

他的表妹Marie Anne le Fèvre de Caumartin，当Le Tonnelier发现她怀孕时被送进了修道院，他在她去世前三天娶了她。他的第二任妻子Gabrielle Anne de Froulay，即沙特莱侯爵夫人的母亲，是在修道院长大的。她在[10]中被描述为“好学而自律”。Le Tonnelier de Breteuil于1697年娶了她，并在买下宫廷职位后安定下来，他一直担任该职位直到1715年路易十四去世。此时他退休到巴黎俯瞰杜伊勒里花园的大房子。Le Tonnelier de Breteuil与妻子和五个孩子住在那里，其中一个孩子是沙特莱侯爵夫人，他们搬进来时大约九岁。他们住在底层，而家族的其他成员住在楼上。

伏尔泰在他的Éloge historique de Madame la Marquise du Châtelet中写道（见[9]）：-

从她最幼小的童年起，她的心灵就通过阅读不止一种语言的优秀作家的作品而得到滋养。她开始翻译《埃涅阿斯纪》，我见过其中几节充满了作者的精神。后来她学习了意大利语和英语；塔索和弥尔顿对她来说就像维吉尔一样熟悉。她在西班牙语方面进展较少，因为有人告诉她，那种语言只有一本著名的书，而这本书是轻浮的。

在他的Mémoires中，伏尔泰写道（见[9]）：-

她的父亲……让她学习拉丁语，她掌握得与达西耶夫人一样好；她能背诵贺拉斯、维吉尔和卢克莱修的精彩段落；西塞罗的所有哲学著作她都熟悉。她最主要的兴趣是数学和哲学。

她的表姐德·克雷基夫人（她嫉妒沙特莱侯爵夫人，并声称自己比沙特莱侯爵夫人大四岁，因此她的描述几乎肯定过于苛刻）对少女时代的沙特莱侯爵夫人作了这样的描述（例如见[6]）：-

我的表妹沙特莱侯爵夫人比我小三四岁，但比我高五六英寸……。她四肢粗大——力气惊人，笨拙得令人称奇。她有一双难看的脚和一双可怕的手。

相当值得注意的是，除了私人教师提供的学业课程外，沙特莱侯爵夫人还接受了击剑、骑马和体操课程。这可能是她父母试图让她克服笨拙，并消耗掉她过剩精力的一种方式。人们可能还会问，她为什么学习数学，但这至少部分要归因于家庭朋友德·梅济耶尔先生对她的鼓励。每天晚上，沙特莱侯爵夫人的父母都会在巴黎的家中招待客人，她经常会在那里见到像贝尔纳·勒布耶·德·丰特奈尔这样的数学家。然而，最重要的是，数学是沙特莱侯爵夫人所热爱的一门学科。

她十六岁时，沙特莱侯爵夫人由父亲引荐进入凡尔赛宫。她喜爱那里的魅力和奢华生活。1725年6月20日，她嫁给了弗洛朗-克洛德·夏特莱侯爵。他是一名军人，被任命为勃艮第地区瑟米尔-昂诺克苏瓦的总督。婚后，沙特莱侯爵夫人在瑟米尔-昂诺克苏瓦度过了一段时间，但她也住在巴黎和其他一些地方。她的丈夫大部分时间都在执行驻防任务，这意味着他长期不在妻子身边。他们的第一个孩子是女儿弗朗索瓦丝·加布里埃尔·波利娜，生于1726年6月30日，而第二个孩子是儿子路易·马里·弗洛朗，生于1727年11月20日。杜沙特莱侯爵夫人的父亲于1728年去世，此后她多次前往克雷泰伊探望母亲。1733年4月，第二个儿子出生，但于1734年9月夭折。然而在此之前，沙特莱侯爵夫人已经结识了伏尔泰。

伏尔泰第一次见到沙特莱侯爵夫人时，她还是个孩子，因为他曾是她父母晚宴上的众多客人之一。在沙特莱侯爵夫人生下第二个儿子后第一次外出时，他们又见面了。她当时已经有过几个情人，这对她这种地位的人来说是当时的习俗。其中一个情人是皮埃尔·莫佩尔蒂，他在她遇到伏尔泰前后正在教她数学。然而，她很快与伏尔泰建立了牢固的关系，他在她身上找到了一个可以讨论他感兴趣的哲学和科学话题的人（几乎肯定是法国唯一这样的女性）。例如，Terrall在[18]中写道，沙特莱侯爵夫人是：-

……她那个时代唯一一位认真发展自己在数学和物理学方面才能的法国女性。

伏尔泰刚从英格兰回来，两人都相信要理解世界就必须将推理应用于科学证据。他们还都坚信艾萨克·牛顿世界观的真实性，而这在当时的法国并不受欢迎。

像沙特莱侯爵夫人这样的女性如何能参与科学讨论？巴黎的Académie des Sciences会议是研究课题讨论的焦点，但这些会议不向女性开放。其他进行讨论的地方是巴黎的咖啡馆，但同样不允许女性进入。1734年有一次，她试图进入Gradot咖啡馆与皮埃尔·莫佩尔蒂讨论数学。这家巴黎咖啡馆作为顶尖数学家、天文学家和物理科学家的聚会场所最为著名，也是皮埃尔·莫佩尔蒂和其他数学家花费许多时间辩论的咖啡馆。然而，Du 沙特莱侯爵夫人被阻止进入，理由是女性不得入内，但她不是那种让习俗决定她能做什么的人。一周后，她再次出现在Gradot咖啡馆，这次打扮成男人。这不是为了欺骗人们，只是为了对她认为荒谬的规则表明立场。她被允许进入，并得到管理层的服务，这让皮埃尔·莫佩尔蒂大为好笑。

1734年5月，伏尔泰和沙特莱侯爵夫人参加了黎塞留公爵（他曾是沙特莱侯爵夫人的另一位情人）的婚礼。几天后，由于他亲英、反法的著作，逮捕令发出，伏尔泰被迫躲藏了几个月。之后他去了西雷，那是沙特莱侯爵夫人丈夫拥有的偏僻宅邸。伏尔泰写道（例如见[9]）：-

我在1733年遇到一位年轻女士，她的感受与我大致相同，她决心在乡间度过数年以修养心智，远离尘世的喧嚣。她就是沙特莱侯爵夫人侯爵夫人，全法国对一切科学最有天赋的女性。……难得有如此出色的头脑和如此多的品味与如此强烈的求知热情结合在一起；但她也热爱上流社会和她的年龄与性别所应有的一切娱乐。尽管如此，她抛开这一切，把自己埋没在香槟和洛林边境上一座破旧的房子里，那里土地非常肥沃也非常丑陋。她美化了房子，增添了宜人的花园。我建了一个画廊，在里面布置了非常精美的科学仪器收藏。我们有一个大图书馆。

沙特莱侯爵夫人的丈夫似乎对这种安排并不感到不快，因为他确实从伏尔泰花费大量金钱改善房子和庄园中受益，而且三人经常一起在西雷。埃诺访问西雷后，写到了沙特莱侯爵夫人和伏尔泰在那里生活的情况（例如见[3]）：-

我也在西雷停留过。那是罕见的景象。他们两人独自在那里，沉浸在欢乐之中。一个在角落里写诗，另一个在她的角落里画三角形。房子的建筑风格是浪漫的，而且惊人地宏伟。

沙特莱侯爵夫人在运用她的数学知识，尽管她继续接受专家的数学辅导。她与数学家的合作不仅仅是以学生的身份，因为她讨论某些问题时更多是以合作者的精神，而非学生的身份。除了继续与皮埃尔·莫佩尔蒂讨论数学外，她还与亚历克西斯·克劳德·克莱罗（同时也是她的情人）进行讨论。到1736年，伏尔泰正在撰写一本书Eléments de la philosophie de NewtonⓉ（《艾萨克·牛顿的哲学原理》），该书以普通读者能理解的方式解释了艾萨克·牛顿的理论。这部作品于1738年以伏尔泰的名义出版，但他在序言中明确指出是与沙特莱侯爵夫人合写的。事实上，有一次他声称这部作品实际上是她的，但这可能夸大了她的贡献。

沙特莱侯爵夫人承担的另一项工作是翻译曼德维尔的The fable of the bees，这是一部关于道德的相当奇特的作品。然而，她并非简单地从英文翻译成法文，因为她删除了部分内容，添加了材料（明确标注），并撰写了序言。这篇序言包含了关于沙特莱侯爵夫人对女性地位的看法的引人入胜的信息（例如见[6]）：-

我充分感受到那种如此普遍地将我们排除在科学之外的偏见的分量；这是生活中一直令我惊讶的矛盾之一，因为法律允许我们决定伟大国家的命运，却没有一个地方训练我们思考……让读者思考一下，为什么在这么多世纪的过程中，从未有女性创作出一部好的悲剧、一首好诗、一个受人尊敬的故事、一幅精美的画作、一本优秀的物理学著作。为什么这些在各方面理解力似乎与男性相似的生物，似乎被某种不可抗拒的力量所阻止，但在她们做到之前，女性将有理由抗议她们所受的教育。……我确信许多女性要么由于教育上的缺陷而没有意识到自己的才能，要么由于偏见而缺乏智力勇气而将其埋没。我自己的经历证实了这一点。偶然的机会让我结识了一些文人，他们向我伸出了友谊之手。……然后我开始相信自己是一个有思想的存在……

巴黎的Académie des Sciences将1737年大奖赛的主题定为火的本质及其传播。伏尔泰和沙特莱侯爵夫人都提交了参赛作品，尽管沙特莱侯爵夫人直到获奖者公布后才告诉伏尔泰她提交了参赛作品。虽然两人都没有获奖，但奖项由莱昂哈德·欧拉获得，Du 沙特莱侯爵夫人的Dissertation sur la nature et la propagation du feuⓉ（《论火的本质与传播》）于1744年由Académie出版，连同伏尔泰的参赛作品和获奖作品一起。

1739年，伏尔泰和沙特莱侯爵夫人前往布鲁塞尔，他们想解决一桩关于沙特莱侯爵夫人丈夫某些财产的诉讼。她决心不让这件事打断她的数学研究，于是带上了大量书籍，还带上了数学家约翰·萨穆埃尔·柯尼希，后者受聘教她代数。Du 沙特莱侯爵夫人在这次旅行中撰写了一本书Institutions de physiqueⓉ（《物理学原理》），该书于1740年出版。莫里斯·克莱因在[15]的一篇评论中写到了这部作品的内容：-

她试图整合笛卡尔、牛顿和莱布尼茨的思想。在哲学方面，她讨论的主题是自由意志、上帝的力量和作用，以及空间、物质和力的本质。

Institutions de physique Ⓣ（《物理学机构》）的出版导致沙特莱侯爵夫人与约翰·萨穆埃尔·柯尼希之间产生分歧，后者似乎觉得这部作品本应属于他。杜沙特莱侯爵夫人从约翰·萨穆埃尔·柯尼希那里了解到哥特弗里德·威廉·莱布尼茨的哲学，这让她如此感兴趣，以至于她决定在书中用一节来阐述他的形而上学理论。因此，在某种程度上，约翰·萨穆埃尔·柯尼希是对的，因为沙特莱侯爵夫人在教她之前对哥特弗里德·威廉·莱布尼茨的思想知之甚少。然而，这并不能使这本书成为他的，也没有任何迹象表明他的贡献超出了作者导师的范围。

沙特莱侯爵夫人的主要工作是对艾萨克·牛顿的Principia的翻译。她使用了Philosophiae naturalis principia mathematica Ⓣ（《自然哲学的数学原理》）的第三拉丁文版，该版由H Pemberton在艾萨克·牛顿的监督下编辑，于1726年在伦敦出版。她于1745年开始翻译工作，次年获得了印刷的皇家特权。一部分于1756年出版，即她去世七年后，由亚历克西斯·克劳德·克莱罗指导，并附有伏尔泰撰写的序言。完整作品于1759年问世，多年来一直是Principia唯一的法文译本。让我们引用伏尔泰的序言（例如见[19]）：-

沙特莱侯爵夫人通过翻译《原理》并为其增添评注，为后世做出了双重贡献。……至于代数评注，它远不止是翻译。沙特莱侯爵夫人将这部分基于亚历克西斯·克劳德·克莱罗的思想。她进行计算，每章完成后，M 亚历克西斯·克劳德·克莱罗检查并纠正。……M 亚历克西斯·克劳德·克莱罗在计算写出后让第三人检查，因此由于疏忽而使错误溜入作品在道德上是不可能的……更令人惊讶的是，一个女人竟能胜任需要如此深度和辛勤工作的任务……她相信死亡早在被带走之前就已来临。从那时起，她唯一的想法就是利用她认为剩下的少量时间来完成她所承担的工作，从而欺骗死亡偷走她认为属于自己一部分的东西。艰苦而坚持不懈的工作，在休息本可挽救她生命时却持续缺乏睡眠，导致了她所预见的死亡。

见该作品在THIS LINK的卷首插图。

沙特莱侯爵夫人在洛林公爵宫廷死于分娩。孩子的父亲是她当时的恋人，诗人Jean-François de Saint-兰伯特，尽管她曾与伏尔泰和Saint-兰伯特密谋制造一种情况，让她的丈夫以为自己是父亲。她42岁，担心自己无法在分娩中幸存。她的儿子21岁，显然不赞成母亲的怀孕。她写信给一位朋友（例如见[6]）：-

我对我的儿子不太满意；我不确定他是否像他应该的那样爱我。他对我的怀孕反应不太好。

她的丈夫、Voltaire 和 Saint-兰伯特 都在她孩子出生时在场。Voltaire 于 1749 年 9 月 4 日写信给 沙特莱侯爵夫人 的一位朋友：-

沙特莱侯爵夫人 告知你，今夜她在书桌前研究 艾萨克·牛顿 时，感到一阵轻微的召唤。这轻微的召唤是一个女儿，瞬间便出现了。她被放在一本四开本的几何书上。母亲已经躺下休息，如果她没有睡着，她会给你写信。

有几天，沙特莱侯爵夫人 担心自己会死的恐惧似乎不会成真。然而，9 月 9 日，她感到非常不适，极度发热。她要求把她一直在翻译的 艾萨克·牛顿 的 Principia 手稿拿给她，并在上面加上了日期“1749 年 9 月 10 日”。不久之后，她失去了意识，在丈夫、Voltaire 和 Saint-兰伯特 都在场的情况下去世。女婴也未能存活。Voltaire 写信给 Mme Denis，她是他的侄女，并在 沙特莱侯爵夫人 去世前几年一直是他的情人（例如见 [3]）：-

我亲爱的，我刚刚失去了一位二十年来一直是我的朋友的人。……亲眼看着她死去，而且是在这样的情况下！为了这样的原因！这太可怕了。

Besterman 在他对“我的朋友”的翻译中加了一个脚注，说：-

这里有一个无法翻译的细微差别：Voltaire 用的是阳性形式“un ami”。

让我们再次引用伏尔泰的序言来结束这篇传记（例如见[19]）：-

没有哪个女人比她更博学，然而也没有人比她更不配被称为蓝袜社成员。她只与那些她认为能从中学习的人谈论科学；她从不为了吸引注意而讨论科学。人们从未见过她聚集那些进行思想论战的小圈子，在那里人们设立某种法庭并对自己的世纪作出评判——而那个世纪随后又会对你作出最严厉的评判。很长一段时间里，她出入于不了解她价值的圈子，而她对此种无知毫不在意。……有一天，我见她当着一位跟不上她思路的数学家的面，完全凭心算，将一个九位数除以另一个九位数。

We should first make some remarks about Émilie du Châtelet's name. Before her marriage her name was Gabrielle-Émilie Le Tonnelier de Breteuil and she was called Gabrielle-Émilie by her family but later she was called simply Émilie by Voltaire and others. We should also note that her husband was the Marquis du Chastellet and her publications appear under the name Madame la Marquis du Chastellet. The spelling "Châtelet" was introduced by Voltaire and has now become standard. In this biography we will call her "Émilie" up to the time of her marriage, and from then "du Châtelet".

Émilie's father was Louis Nicolas Le Tonnelier de Breteuil. He was an official at the Court of Louis XIV at Versailles with property in Paris and also land in Touraine. He is variously described ([6] and [8]) as:-

... a charmer in his youth... fashionable but slightly ridiculous ... nobody liked him very much ...

His cousin, Marie Anne le Fèvre de Caumartin, was sent to a convent when Le Tonnelier realised she was pregnant and he married her three days before she died. His second wife, Gabrielle Anne de Froulay who was Émilie's mother, was brought up in a convent. She is described in [10] as "studious and disciplined". Le Tonnelier de Breteuil married her in 1697 and settled down after buying a position at Court which he held until Louis XIV died in 1715. At this stage he retired to his big house in Paris overlooking the Tuileries gardens. Le Tonnelier de Breteuil lived there with his wife and five children, one being Émilie who was about nine years old when they moved in. They lived on the ground floor while other members of the family lived on the floors above.

Voltaire wrote in his Éloge historique de Madame la Marquise du Châtelet (see [9]):-

From her most tender childhood, her mind was nourished by reading good authors in more than one language. She started a translation of the Aeneid and I have seen several sections of this filled with the spirit of the author. Later she learnt Italian and English; Tasso and Milton were as familiar to her as Virgil. She made less progress in Spanish, because she was told that there is only one famous book in that language and that this book is frivolous.

In his Mémoires Voltaire wrote (see [9]):-

Her father ... made her learn Latin, which she knew as well as Mme Dacier; she knew the finest passages of Horace, Virgil and Lucretius by heart; all the works on philosophy by Cicero were familiar to her. Her dominant taste was for mathematics and philosophy.

Her cousin, Mme de Créqui (who was jealous of Émilie and claimed she was four years older than she was, so is almost certainly unduly cruel in her description) wrote this description of the teenage Émilie (see for example [6]):-

My cousin Émilie was three or four years younger than I, but five or six inches taller ... . She was a colossus in all her limbs - a marvel of strength and a prodigy of clumsiness. She had terrible feet and formidable hands.

It is rather remarkable that, in addition to the academic lessons provided by private tutors, Émilie was given lessons in fencing, riding, and gymnastics. This may have been an attempt by her parents to have her overcome her clumsiness and also to use up some of the excess energy she possessed. One might also wonder why she studied mathematics but this must be due at least in part to the fact that M de Mézières, a family friend, encouraged her. Every night Émilie's parents entertained guests in their Paris house and she would have seen mathematicians like Bernard de Fontenelle there frequently. Most of all, however, mathematics was a subject Émilie loved.

When she was sixteen years old Émilie was introduced to the Court at Versailles by her father. She loved the glamour and extravagant life there. She was married on 20 June 1725 to the Marquis Florent-Claude Chastellet. He was a military man who was made governor of Semur-en-Auxois in Burgundy. After the marriage du Châtelet spent time in Semur-en-Auxois but she also lived in Paris and a number of other places. Her husband spent most of his time on garrison duties which meant that he spent long periods away from his wife. Their first child was a daughter, Françoise Gabriel Pauline, born on 30 June 1726, while their second child was a son, Louis Marie Florent, born on 20 November 1727. Du Châtelet's father died in 1728 and after that she made a number of visits to her mother at Créteil. In April 1733 a second son was born but he died in September 1734. Before this, however, du Châtelet had met Voltaire.

Voltaire first met du Châtelet while she was still a child for he had been one of the many guests at their parents dinner parties. They met again on one of the first occasions that du Châtelet went out after the birth of her second son. She had already had a number of lovers which was the custom of the time for someone of her status. One lover was Maupertuis who was teaching her mathematics around the time that she met Voltaire. However, she quickly developed a strong relationship with Voltaire and he found in her someone (almost certainly the only woman in France) with whom he could discuss the philosophical and scientific topics which interested him. For example Terrall writes in [18] that du Châtelet was:-

... the only French woman of her time seriously to develop her talent for mathematics and physics.

Voltaire had just returned from England, and the two shared a belief that to understand the world one must apply reasoning to scientific evidence. They also both were firmly convinced of the truth of Newton's world view which at that time was unpopular in France.

How could a woman like du Châtelet participate in scientific discussions? The meetings of the Académie des Sciences in Paris were the focus of discussions on research topics but these were not open to women. The other places where discussions took place were the cafés of Paris but again women were not allowed to enter them. On one occasion in 1734 she tried to go into the Café Gradot to discuss mathematics with Maupertuis. This Paris café was the most famous as a meeting place of the top mathematicians, astronomers and physical scientists and it was the café where Maupertuis and other mathematicians spent many hours in debate. Du Châtelet, however, was prevented from entering on the grounds that women were not admitted but she was not one to allow convention to dictate what she might do. A week later she appeared at the Café Gradot again, this time dressed as a man. It was not an attempt to fool people, just to make a statement on what she believed was a ridiculous rule. She was allowed in and served by the management, much to Maupertuis' amusement.

In May 1734 Voltaire and du Châtelet attended the wedding of the Duc de Richelieu (who had been another of du Châtelet's lovers). Days later Voltaire was forced to hide for a couple of months after a warrant was issued for his arrest because of his pro-English, anti-French writings. After that he went to live at Cirey, which was the remote house owned by du Châtelet's husband. Voltaire wrote (see for example [9]):-

I found in 1733 a young lady who felt more or less as I did, and who resolved to spend several years in the country to cultivate her mind, far from the tumult of the world. It was the marquise Du Châtelet, the woman who in all France had the greatest disposition for all the sciences. ... Seldom has so fine a mind and so much taste been united with so much ardour for learning; but she also loved the world and all the amusements of her age and sex. Nevertheless she left all this to go and bury herself in a dilapidated house on the frontiers of Champagne and Lorraine, where the land was very fertile and very ugly. She beautified the house, to which she added pleasant gardens. I built a gallery, in which I created a very fine collection of scientific instruments. We had a large library.

Du Châtelet's husband does not seem to have been unhappy at this arrangement, for he certainly benefited from Voltaire spending large amounts of money improving the house and estate, and frequently the three were at Cirey together. Hénault, after visiting Cirey, wrote about the life du Châtelet and Voltaire lived there (see for example [3]):-

I also stopped at Cirey. It is a rare sight. The two of them are there alone, plunged in gaiety. One writes verse in his corner, the other triangles in hers. The architecture of the house is romantic and surprisingly magnificent.

Soon du Châtelet was putting her mathematical knowledge to use although she continued to have mathematical tuition from experts. It was not simply as a pupil that she worked with mathematicians, for she discussed some topics more in the spirit of a collaborator rather than a pupil. As well as continuing to discuss mathematics with Maupertuis, she also did so with Clairaut (who also was her lover). By 1736 Voltaire was working on a book Eléments de la philosophie de Newton Ⓣ which explained Newton's theories in terms that a general reader could understand. It was a work which appeared under Voltaire's name in 1738 but one which he states clearly in the Preface was written jointly with du Châtelet. In fact on one occasion he stated that the work was really hers but this was probably overstating her contribution.

Other work undertaken by du Châtelet was a translation of Mandeville's The fable of the bees which is a rather strange work on morals. She did not simply translate it from English to French, however, for she omitted sections, added material (clearly indicated) and wrote a Preface. This Preface contains fascinating information about du Châtelet's views on the position of women (see for example [6]):-

I feel the full weight of the prejudice which so universally excludes us from the sciences; it is one of the contradictions in life that has always amazed me, seeing that the law allows us to determine the fate of great nations, but that there is no place where we are trained to think ... Let the reader ponder why, at no time in the course of so many centuries, a good tragedy, a good poem, a respected tale, a fine painting, a good book on physics has ever been produced by a woman. Why these creatures whose understanding appears in every way similar to that of men, seem to be stopped by some irresistible force, but until they do, women will have reason to protest against their education. ... I am convinced that many women are either unaware of their talents by reason of the fault in their education or that they bury them on account of prejudice for want of intellectual courage. My own experience confirms this. Chance made me acquainted with men of letters who extended the hand of friendship to me. ... I then began to believe that I was a being with a mind ...

The Académie des Sciences in Paris set the topic for the Grand Prix of 1737 to be on the nature of fire and its propagation. Both Voltaire and du Châtelet submitted entries, although du Châtelet did not tell Voltaire until after the winners were announced that she had submitted an entry. Although neither won, the prize was won by Euler, Du Châtelet's Dissertation sur la nature et la propagation du feu Ⓣ was published by the Académie in 1744 along with the submissions of Voltaire and the winning entries.

In 1739 Voltaire and du Châtelet travelled to Brussels where they wanted to settle a law suit regarding some property of du Châtelet's husband. Determined not to allow this to interrupt her studies of mathematics she took large quantities of books with her and also the mathematician Samuel König who was engaged to teach her algebra. Du Châtelet worked on a book, Institutions de physique Ⓣ while on this trip and it was published in 1740. M Kline writes about the contents of this work in a review of [15]:-

She attempted to integrate Cartesian, Newtonian, and Leibnizian ideas. On the philosophic side the themes she discusses are free will, God's power and role, and the nature of space, matter, and force.

Publication of Institutions de physique Ⓣ led to a disagreement between du Châtelet and Samuel König who seems to have felt that the work was his. Du Châtelet had learnt of Leibniz's philosophy from Samuel König and it had so interested her that she had decided to devote a section of her book to his theories of metaphysics. To an extent, therefore, König was right for du Châtelet knew little of Leibniz's ideas before he taught her. However this does not make it his book and there is nothing to suggest that his contribution was any more than that of teacher of the author.

Du Châtelet's major work was a translation of Newton's Principia . She used the third Latin edition of Philosophiae naturalis principia mathematica Ⓣ, edited by H Pemberton under Newton's supervision, which had been published in London in 1726. She began work on the translation in 1745 and the Royal Privilege for printing was granted to her in the following year. A part was published in 1756, seven years after her death, under the direction of Clairaut with a preface written by Voltaire. The complete work appeared in 1759 and was for many years the only translation of the Principia into French. Let us quote from Voltaire's Preface (see for example [19]):-

Mme du Châtelet has rendered a double service to posterity with her translation of the Principia and enriching it with a commentary. ... As regards the algebraic commentary, it is much more than a translation. Mme du Châtelet based this part on the ideas of Clairaut. She worked out the calculations and after each chapter was completed, M Clairaut checked and corrected it. ... M Clairaut had the calculations checked by a third person after they were written out so that it was morally impossible that an error would slip into the work due to an oversight ... It is more astonishing that a woman should have been capable of a task which required such depth and hard work ... She believed that death was coming long before she was taken from us. From then on her one thought was to use the little time she thought that remained to complete the work she had undertaken and so cheat death of stealing what she considered was part of herself. Hard and persevering work, continual lack of sleep when rest might have saved her life, led to the death she had foreseen.

See the frontispiece of this work at THIS LINK.

Du Châtelet died in child birth at the court of the Duke of Lorraine. The father of the child was her lover at that time, the poet Jean-François de Saint-Lambert, although she had plotted with Voltaire and Saint-Lambert to engineer a situation in which her husband thought he was the father. She was 42 years old and feared that she would not survive child-birth. Her son was 21 and clearly disapproved of his mother's pregnancy. She wrote to a friend (see for example [6]):-

I am less pleased with my son; I am not sure whether he loves me as much as he should. He did not take my pregnancy very well.

Her husband, Voltaire and Saint-Lambert were all present at the birth of her child. Voltaire wrote to one of du Châtelet's friends on 4 September 1749:-

Mme du Châtelet informs you that this night, being at her desk working on Newton, she felt a little call. The little call was a daughter, who appeared in an instant. She was laid on a quarto book of geometry. The mother has gone to lie down and, if she were not asleep, she would be writing to you.

It seemed for a few days that du Châtelet's fear that she would die would not be realised. However, on 9 September she felt very unwell and extremely hot. She asked to be given the manuscript of the translation of Newton's Principia that she had been working on and added the date "10 September 1749" to it. Soon after that she lost consciousness and died with her husband, Voltaire and Saint-Lambert all present. The baby girl did not survive either. Voltaire wrote to Mme Denis, who was his niece and had been his lover for some years prior to du Châtelet's death (see for example [3]):-

My dear, I have just lost one who was my friend for twenty years. ... To have seen her die, and in such circumstances! and for such a reason! It is frightful.

Besterman adds a footnote to his translation of "my friend" saying:-

There is an untranslatable nuance here: Voltaire wrote "un ami" in the masculine.

Let us end this biography by quoting again from Voltaire's Preface (see for example [19]):-

No woman was ever more learned than she was, yet no one deserved less than she did to be called a blue-stocking. She only ever spoke about science to those from whom she thought she could learn; never did she discuss it to attract attention to herself. She was not ever seen gathering around her those circles which wage battles of the mind, where one sets up a kind of tribunal and passes judgement on one's century - which then in its turn judges you most severely. For a long time she moved in circles which did not know her worth and she paid no attention to such ignorance. ... I saw her, one day, divide a nine-figure number by nine other figures, in her head, without any help, in the presence of a mathematician unable to keep up with her.