Philosopher, scientist, physician, and journalist.

Repeatedly requested Franklin’s presence at a series of experiments he carried out to prove that from fire emanates a fluid which may be made visible; Franklin was eventually witness to several of these experiments.

His first work, A Philosophical Essay on Man (1773), an attack on Helvétius and Voltaire, was translated into French (1775). Published a political pamphlet, The Chains of Slavery (1774). Received as a Freemason in London (1775).

Granted the degree of Doctor of Medicine (1775) by the University of St. Andrews in Scotland, from which Franklin also held an honorary degree. Settled in Paris, where he became the médecin des gardes du corps du comte d’Artois (1777).

Studied fire and electricity (1779). Published his study, Découvertes de M. Marat sur le Feu, l’Electricité et la Lumière … (1779), and several other scientific treatises.

Sought to disprove Newton’s theories of color and to establish the existence of three primary colors. Wrote Notions élémentaires d’optique (1784).

Founded and directed one of the most influential and widely read newspapers of the French Revolution, l’Ami du Peuple ou le Publiciste parisien (1789-92).

A famous French revolutionary, he campaigned for the execution of Louis XVI (1792-93). Stabbed to death in his bathtub by a young woman.

Born in Boudry, Switzerland.