“JEAN PAUL MARAT,” says he, “was born at Boudry, near Neufchatel, in Switzerland, on April 13, 1742. His father, who spelt his name ‘MARA,’ was a physician of some ability, and on being exiled from his native island of Sardinia for abandoning the Roman Catholic religion, had taken up his residence in Switzerland; and married a Swiss Protestant. JEAN PAUL was the eldest of three sons; his next brother settled down as a watchmaker at Geneva, and his youngest brother entered the service of the Empress Catherine, and distinguished himself in the Russian army under the title of the Chevalier de Boudry. JEAN PAUL was from his childhood of an intensely sensitive and excitable disposition, and also so quick at his books that he became a good classical scholar, and acquainted with most modern languages. As his chief taste, however, seemed to be for natural science, he was intended to follow his father’s profession, and was, at the age of eighteen, sent to study medicine at the University of Bordeaux. He there obtained a thorough knowledge of his profession, but devoted himself particularly to the sciences of optics and electricity. From Bordeaux he went to Paris, where he effected a remarkable cure of a disease of the eyes, which had been abandoned as hopeless both by physicians and quacks, by means of electricity. From Paris he went to Amsterdam, and, finally, to LONDON, where he set up in practice in _Church Street, Soho_, then one of the most fashionable districts in London. He must soon have formed a good practice, for he stopped in London, with occasional visits to Dublin and Edinburgh, for ten years, and only left it to take up an appointment at the French court. While in London he wrote his first book, and in 1772 and 1773, he published the first two volumes of a philosophical and physiological _Essay on Man_. The point he discussed was the old problem of the relation between body and mind, and he treated it in a very interesting manner from the physiological point of view. He held some extraordinary theory about the existence of some fluid in the veins which acted on the mind; which, however, does not impair the interest of his inquiries into the cause of dreams, or diminish the respect felt for his wide reading and extensive knowledge both of ancient and modern philosophical and medical authors. He shows a wide knowledge of Latin and Greek literature, and while writing in good English freely quotes French, German, Italian, and Spanish writers. In one part of his book he declared that it was ridiculous for any one to make psychical researches without having some knowledge of anatomy and physiology, and openly attacked HELVÉTIUS for despising scientific knowledge in his famous _De l’Esprit_. VOLTAIRE naturally took the side of HELVÉTIUS, and did the young author the honour of noticing, and very severely criticising, his book. MARAT himself translated it into French, and published it at Amsterdam in 1775.