Courtois discovered iodine, which, medical importance aside, made early photography possible, and jointly discovered morphine. He grew up around Guyton de Morveau’s Dijon academy — his father worked there, the family lived there. Thénard, the same age, became a good friend when both got jobs under Fourcroy in Paris. Helping another researcher there, Séguin, Courtois isolated morphine (Séguin tried to claim all the credit). Too preoccupied with business to research further, Courtois gave samples of iodine to his friends Clément and Desormes, who passed it on to Ampère, Chaptal, Gay-Lussac and ultimately Davy.