Before the Revolution, Jean-Paul Marat was a physicist who challenged Newton
Jean-Paul Marat is remembered as the firebrand journalist of the French Revolution, killed in his bath in 1793. Years earlier he was a London doctor, a court physician and an experimental scientist who ran 166 fire experiments, argued Newton was wrong about colour, and impressed Benjamin Franklin while infuriating Lavoisier.
Born Mara in Boudry, in the principality of Neuchâtel, on 24 May 1743, he was taught largely at home by his father, a textile designer and language teacher. At 17 he applied to join an expedition to Tobolsk to observe the transit of Venus and was rejected. He later wrote that the love of glory was the one passion that never left him. After Bordeaux and Paris he settled in 1765 in Soho, practising medicine without a formal qualification, and moved among artists such as Antonio Zucchi and Angelica Kauffman. St Andrews granted him an MD in 1775.
His London book Chains of Slavery, from 1774, attacked corruption, patronage, standing armies and censorship, and he sent it to John Wilkes. A philosophical treatise on mind and body drew a mocking reply from Voltaire. In 1777 he became physician to the bodyguard of the Comte d'Artois, brother of Louis XVI, at 2,000 livres a year, and used his spare time for experiments on fire, light and electricity.
Science brought him into conflict with the establishment. His Research into the Physics of Fire described 166 experiments meant to show that fire was an igneous fluid rather than a material element. An Academy of Sciences commission praised the experiments but not the conclusions, and when Marat advertised the report as an endorsement, Lavoisier demanded a correction. His work on light, arguing that prismatic colours came from diffraction at an aperture's edges and that there were three primary colours rather than seven, was also rejected. Marat came to see an academic cabal defending Newton, though Franklin reportedly admired his skill.
In the Revolution his newspaper L'Ami du peuple made him the voice of Parisian sans-culottes, printed on his own press as authorities tried to shut it down. Elected to the National Convention in 1792, he sided with the Montagnards and called ever more openly for violence against supposed enemies. On 13 July 1793 the Girondin sympathiser Charlotte Corday killed him while he bathed to soothe a skin disease. Jacques-Louis David staged his funeral, and he entered the Panthéon in 1794, only to be removed in February 1795.
Source: Jean-Paul Marat
