The numerous monuments of remote antiquity scattered over the hills and promontories of Cornwall, made also deep impressions on his mind, and he availed himself of every resource placed within his reach, by previous learning and erudition, to acquire a knowledge of the Druidical learning, and of the manners and customs of the ancient Britons previously to their becoming Christians. In 1750 he was elected a Fellow of the Royal Society, and in 1753 published in a folio volume, at Oxford, “The Antiquities of Cornwall.” A second edition in the same form came out at London in the year 1769, with considerable additions, under the following title: “Antiquities, Historical and Monumental, of the County of Cornwall, consisting of several Essays on the ancient Inhabitants, Druid Superstition, Customs, and Remains of the most remote Antiquity in Britain and the British Isles; exemplified and proved by Monuments now extant in Cornwall and the Scilly Islands: with a Vocabulary of the Cornu-British language. Revised, with several additions, by the Author.” His next publication had for its title, “Observations on the ancient and present state of the Islands of Scilly, and their importance to the Trade of Great Britain,” Oxford, 1756, 4to. This work was an extension of a paper, read before the Royal Society in 1753. In 1758 came out his “Natural History of Cornwall, with Engravings of all the specimens, both animate and mineral, deemed to be of curiosity or of importance,” printed also at Oxford, in one volume folio, the original specimens and many antiquities being deposited in the Ashmolean Museum. All these works, executed with great ability, patient diligence, and skill, raised the reputation of the author so high throughout the learned world, that in March 1766, the University of Oxford conferred on him their highest honour, the degree of Doctor by diploma, which he lived to enjoy somewhat more than six years, having departed this life on the 31st of August, 1772. Besides his literary correspondence with various learned men, he carried on one of peculiar frequency with the great poet of his age, Mr. Alexander Pope, and a large collection of Mr. Pope’s letters to him is still extant, with a variety of other papers, obviously intended for publication. Dr. Borlase furnished Mr. Pope with many Cornish fossils to decorate his celebrated grotto at Twickenham, where the donor’s name was scored in capitals of the most splendid materials; and in a letter written on the occasion, Mr. Pope says, “I am much obliged to you for your valuable collection of Cornish diamonds. I have placed them where they may best represent yourself, in a shade, but shining.”