His next work was of a political character. He had got mixed up with some of the popular societies in England, which were striving to obtain a thorough reform of the representation of the people in the House of Commons, and, in 1774, published a work, which he entitled THE CHAINS OF SLAVERY. In this book, which is partly historical and partly political, he begs the electors to take more care in the choice of their representatives. It is written in a very declamatory style, and strikes the note of the responsibility of representatives to their constituents, which is the key-note of all his political ideas. The book is published in quarto, and is printed on fine paper, so that it can hardly have been meant to appeal to the populace, but it, nevertheless, procured him the honorary membership of the popular societies of _Newcastle_ and other great northern cities. Subsequently he again returned to his profession, and after publishing a medical tract in 1775, of which no copy is known to exist, he published _An Inquiry into the Nature, Cause, and Cure of a singular Disease of the Eyes_, in 1776. [See _Academy_ of September 23, 1882.] In this little pamphlet there is no violent language; it describes the disease and the cases he had cured in perfectly simple language, and shows, at least, that he was no mere quack, but a scientific physician. On June 30, 1775, he had, while on a visit to _Scotland_, received the honorary degree of M.D. from the _University of St. Andrews_ for his eminence as a doctor, and had probably received similar compliments from other Universities, because, on June 24, 1777, JEAN PAUL MARAT, ‘médecin de plusieurs facultés d’Angleterre,’ was appointed, for his good character and high reputation as a doctor, physician to the body-guard of the Comte d’Artois, with a salary of a thousand livres a year and allowances. To take up this court appointment he moved to Paris, and soon acquired a large practice there, and the name of ‘physician of the incurables,’ from the number of hopeless cases he was successful in treating. He also moved in the best society about the court, and won the affections of the _Marquise de l’Aubespine_ for saving her life. For some reason or other, most probably because he had obtained a competent fortune, and desired to satisfy his ambition, he resigned his court appointment in 1783, and devoted himself to science. He had long observed the phenomena of Heat, Light, and Electricity, and in the course of the next five years published the result of his experiments, and presented them to the _Academy of Sciences_. His hard work won him the friendship of BENJAMIN FRANKLIN, but the violence with which he attacked his adversaries, and his audacity in doubting the conclusions of NEWTON, prevented him from obtaining a seat in the Academy of Sciences. When he recognised that this hostility to himself prevented due recognition of his work, he determined to win the approbation of the Academy by concealing his name;