Antoine Laurent de Lavosier

"In nature, nothing is created, nothing is lost, everything is transformed" (Antoine de Lavoisier).

Lavoisier was born in Paris in 1743. Son of an upper-middle-class family he studied at the best French schools. He graduated in law, but never practiced the profession. Hooked by chemistry, he became a great scientist. At the age of 23 he was elected a member of the French Academy of Sciences and, for his talent, was soon appointed to the post of director of the Powder Administration, one of the academy's committees.
But in 1768 Lavoisier seemed to move away from the scientific world. He went to work at Ferme Générale, a government agency responsible for tax collection. Lavoisier stated that his goal at Ferme Générale was to raise money to fund his research. Still, his connection with this company considered corrupt was bad-tempered by the population.
At 29, Lavoisier married Anne-Marie, the 13-year-old daughter of one of Ferme Générale's partners. The scientist's wife played a major role in Lavoisier's research. She was the one who translated scientific works from English to French, followed her husband's experiences, made notes and illustrations.

To devote himself to science and work, Lavoisier adopted a rigorous daily routine. He woke up at six in the morning and worked on his research until eight. He then dealt with the business of Ferme Générale, the Administration of Gunpowder and other committees of the French Academy of Sciences. From seven to ten at night, he returned to his studies. Sunday was the "day of happiness," when the scientist was experimenting.
In 1789 Lavoisier launched the Elementary Treaty of Chemistry, a work that would be considered of great importance to science. At the same time, France was going through a complicated period. The poorer classes of the population, from which the government collected taxes, rebelled and the French Revolution began. Lavoisier's connection with Ferme Générale cost him his life: he was accused of embezzling public money and killed in the guillotine in 1794.
It is said that the day after Lavoisier's death, the famous mathematician Joseph-Louis Lagrange would have said, "It took only a moment to cut off his head, but perhaps a century is not enough to produce another one."