Marie-Anne Pierrette Paulze, better known as Marie Lavoisier and "mother of modern chemistry"

January 20, 1758, in Montbrison (France) – February 10, 1836, in Paris (France)

Motherless, at the age of 3 she was sent to a convent where she could receive one of the highest quality educations that could be had at that time. She learned several languages and became a talented cartoonist.

At the age of 13, she was asked to marry the Count of Amerval, who was three times her age. Her father, a financial and parliamentary lawyer tried to oppose her, but he was threatened with losing her job if he refused. So she consulted with one of her colleagues and friend, Antoine Laurente Lavoisier, who was 28 years old, was a nobleman, a lawyer, an economist and a chemist if he was willing to marry his daughter. He accepted and they were married on December 16, 1771.

The Lavoisier couple moved in 1775 to Paris. Antoine, a lawyer and economist, continued to work for Ferme-Générale, and was also appointed administrator of gunpowder at the Arsenal in Paris. With the financial security that this entailed, he was able to build a laboratory. Marie-Anne began to take an interest in chemistry, to become involved in Antoine's scientific research and to actively participate in laboratory work. Marie-Anne began her formal training in the field of chemistry with two of Antoine's colleagues, Jean-Baptiste Bucquet and Philippe Gingembre.

It was customary to see the Lavoisiers spend most of their free time together in the laboratory, working as a team. Marie-Anne assisted her husband, writing down observations, drawing diagrams of his experimental designs, which was very helpful in understanding Antoine's methods and results, and organizing and editing reports.

Both remade the field of chemistry, which until then was dominated by the idea of phlogiston, coming from alchemistry, spread by Georg Stahl. It was considered to be a fire-like element that was released during combustion, and this concept was used to describe the apparent properties of the changes that matter underwent when burned. Marie-Anne herself was fluent in English, Latin and French and did translations on various works related to phlogiston. Perhaps, the most important translation of it has been that of the publication "Essay on Phlogiston" by Richard Kirwan, since at the same time Madame Lavoisier criticized it, adding footnotes in which she pointed out the chemical errors of the work. It was his translations and his comments that led Antoine to be convinced that the phlogiston hypothesis was incorrect and to direct his investigations towards combustion and the discovery of oxygen.

He also translated publications by other great scientists such as Joseph Priestley and Henry Cavendish, who were an important support for Antoine.

During the French Revolution, in 1793, Antoine was accused of treason due to his prominent position in the Ferme-Générale and the father of Marie-Anne as well. Both were arrested. Marie-Anne fought for her freedom and, herself, defended her husband against Antoine Dupin, who had denounced him and who also had the power to save him, appealing to the scientific research they carried out and the importance they had for France. However, Antoine and his father were executed on May 8, 1794, in Paris.

All of Marie-Anne's assets were confiscated by the government, including the research documentation and the laboratory, although she managed to save part of it and publish it as Lavoisier's Memoirs of Chemistry, laying the foundations of modern chemistry.

Some years later, Marie-Anne remarried Benjamin Thompson, Earl of Rumford, one of the best-known physicists of his time, but the marriage did not prosper and they ended up separating.

Throughout her life, Marie-Anne kept the surname Lavoisier, showing her devotion to it and receiving the nickname "mother of modern chemistry" because she was directly involved in the creation and modeling of the ideas that separated alchemy from a modern, rational and exact science.