During his residence at Oxford, Gilbert was a regular attendant at the lectures on anatomy and mineralogy, delivered by Dr. Thompson, at Christ Church. He also attended with assiduity the lectures on chemistry and botany of Drs. Beddoes and Sibthorp, with whom he contracted a friendship, which terminated only with their lives. To the former of these two gentlemen Gilbert subsequently introduced his friend Sir Humphry Davy, at that time in comparatively humble life, but whose extraordinary combination of poetical and philosophical genius had attracted Gilbert's attention, and he thus had the merit and good fortune of contributing to rescue from obscurity one of the greatest discoverers in modern chemistry. Mr. Gilbert continued to reside principally at his college until the year 1793, when, having previously taken the honorary degree of M.A., he returned to Cornwall to serve as sheriff, and to divide his time, between the cultivation of science and literature, and the duties of a magistrate in a populous and busy town. Previous to this, in the year 1791, he had been elected a Fellow of the Royal Society, his certificate describing him as being "devoted to mathematical and philosophical pursuits." It was signed by Thomas Hornsby, Savilian professor of astronomy, G. Shuckburgh, N. Maskelyne, George Staunton, and other Fellows. In 1804 Mr. Gilbert became a member of Parliament for Helstone, and at the general election in 1806, was chosen to represent Bodmin, continuing to sit for that borough until December, 1832. He was emphatically the representative of scientific interests in the House of Commons, and was continually appointed to serve on committees of inquiry touching scientific and financial questions. He acted as Chairman of the committee for rebuilding London Bridge, causing it to be widened ten feet more than originally proposed, and he greatly contributed by his exertions to carry many very important public projects, amongst which may be mentioned, the Breakwater at Plymouth, and the bill for the revision of weights and measures, of which he was appointed a commissioner. He was also a member of the Board of Longitude. On the 8th of April, 1808, he married Mary Ann Gilbert, only niece of Charles Gilbert of Eastbourne in Sussex, under whose will he came into possession of considerable estates in that county; and, in compliance with its conjunctions, obtained permission to assume the name and arms of Gilbert.