Mr. Gilbert contributed several important papers on mathematical subjects to the 'Philosophical Transactions.' In July, 1819, he succeeded Samuel Lyons in the office of treasurer to the Royal Society, which office he retained until elected President in 1828. He was also the author of numerous papers in the 'Quarterly Journal of Science and Arts,' and presented the world with the fruits of his labours as an antiquary, by publishing, in 1838, 'The Parochial History of Cornwall,' in four volumes 8vo., founded on the manuscript histories of Mr. Hals and Mr. Tonkin. Mr. Gilbert was a diligent collector of ancient traditions, legendary tales, songs, and carols, illustrating the manners of the Cornish peasants, and printed various ballads at his house at Eastbourne. He possessed great memory and powers of quotation and anecdote; his conversation has been described as being a continued stream of learning and philosophy, adapted with excellent taste to the capacity of his auditory, and enlivened with anecdotes to which the most listless could not but listen and learn. "His manners," says Dr. Buckland, "were most unaffected, childlike, gentle, and natural. As a friend, he was kind, considerate, forbearing, patient, and generous; and when the grave was closed over him, not one man, woman, or child, who was honoured with his acquaintance, but felt that he had a friend less in the world." Mr. Gilbert retired from the chair of the Royal Society in 1830, and two years later from Parliament; he did not, however, resign himself to repose, but continued in many ways still to advocate the cause of science. In 1839 he became much weaker in health and spirits; and although he made a journey to Durham, and afterwards into Cornwall, where he presided for the last time at the Anniversary of the Royal Geological Society of Cornwall (of which he had been President since its institution in 1814), he was evidently unequal to the exertions he was making. His last visit was to Oxford, which University had some years before conferred on him the title of D.C.L. From that period he never went into public, but, bidding farewell to London, retired to his house at Eastbourne on the 7th of November, 1839, where he died on the 24th of the following December. His body was borne to the grave by his own labourers, and followed by his widow and family, which consisted of one son (the present J. D. Gilbert, F.R.S.) and two daughters.--_Weld's History of the Royal Society, with Memoirs of the Presidents._ London, 1848. CHARLES HATCHETT, F.R.S. Born January 2, 1765. Died March 10, 1847.