Louis Claude Cadet de Gassicourt (24 July 1731 – 17 October 1799) was a French chemist who synthesised the first organometalic compound.
He obtained a red liquid by the reaction of potassium acetate with arsenic trioxide.
He was the brother of the pharmacist Antoine-Alexis Cadet de Vaux.
Marie Thérèse Françoise Boisselet became his wife in 1771, at that time her son, fathered by Louis XV, was two years old.
[1] In 1825, botanist Antoine Laurent Apollinaire Fée circumscribed Gassicurtia which is a genus of lichenized fungi in the family Caliciaceae and named in Cadet de Gassicourt's honor.