In the year 1798, the Elector appointed him his ambassador to the court of Great Britain; but on arriving in London, Rumford, much to his mortification, found that, as a British subject he could not hold that office. Shortly after this, in 1799, his friend and patron the Elector Charles Theodore died. Deeply grieved by the loss he had sustained, Rumford contemplated returning to his native country, in compliance with a formal invitation which he had received from the United States government. He was, however, led to change this design, and remain for several years in London, during which period he devoted the greatest portion of his time to the interests of the Royal Institution, of which he may be considered the founder. The objects of this institution, now one of the recognised scientific establishments of the world, and which can boast of having given employment to such men as Young, Davy, Brande, and Faraday, were "to diffuse the knowledge and facilitate the general introduction of useful mechanical inventions and improvements, and to teach by courses of philosophical lectures and experiments the application of science to the useful purposes of life." Such an institution was precisely the one which Rumford was qualified to superintend; and in its early history, the influence of his peculiar habits of thought is discernible, in the choice of subjects for investigation by the members. Rumford's name will ever be connected with the progress of science in England, from the establishment of this institution, and also from the foundation by him of a perpetual medal and prize in the gift of the Royal Society, for the reward of discoveries connected with light and heat. During the latter portion of his life, Count Rumford, retaining an income of 1200_l._ a year from the Bavarian court, resided chiefly at Auteuil, a small villa near Paris. Here he was married again to the widow of the eminent French chemist Lavoisier, his former wife having died in 1792. Rumford's death took place at Auteuil, on the 21st of August, 1814, in the sixty-second year of his age. His only daughter by his first wife inherited the title of Countess of Rumford, with the continuation of her father's Bavarian pension. She married Cuvier the naturalist, and survived until a few years ago, forming a link between the age of Lavoisier and those of the middle of the nineteenth century.--_Chambers' Miscellany_, No. 161.--_Encyclopædia Britannica_, eighth edition.--_Voyage de trois mois en Angleterre, en Ecosse, &c., par Marc-Auguste Pictet, F.R.S., &c._ Geneva, 1802. DANIEL RUTHERFORD, M.D. Born November 3, 1749. Died November 15, 1819.