[Footnote 15: William Gilbert, M.D. chief physician to Queen Elizabeth and King James I. He published a treatise, "_De Magnete, magnetecisque corporibus, et de magno magnete Tellure Physiologia Nova_. London, 1600, folio." This treatise on the magnet is termed by the great Bacon "a painful and experimental work." Gilbert also invented two instruments for the use of seamen in calculating the latitude, without the aid of the heavenly bodies. He died A.D. 1603.] [Footnote 16: The Hon. Robert Boyle, who so laudably distinguished his name by his experimental researches, was a son of the great Earl of Corke. He was about this time actively engaged in the formation of the Royal Society, of which he may be considered as one of the principal founders. This necessarily placed his merits under Dryden's eye, who was himself an original member of that learned body. His _great brother_ was Roger Lord Broghill, created upon the Restoration Earl of Orrery, to whom Dryden dedicated the "Rival Ladies." See Vol. II. p. 113.] [Footnote 17: William Harvey, the famous discoverer of the circulation of the blood. His _Exercitatio Anatomica de motu cordis et sanguinis_, was printed at Frankfort, 1627. He adhered to his master Charles I. during the civil wars; and when his affairs became desperate, retired to privacy in London. His last treatise, entitled, _Exercitatio de generatione Animalium_, was published in 1651, at the request of Dr George Ent, a learned physician, mentioned by Dryden in the next line. This gentleman, in a dedication to the President and College of Physicians, gives a detailed account of the difficulty which he had in prevailing on the aged and retired philosopher to give his work to the press, which he only consented to do on Dr Ent's undertaking the task of editor. Harvey died in June 1667. Ent himself was a physician of eminence, and received the honour of knighthood from Charles II. He defended Dr Harvey's theory of circulation against Parisanus, in a treatise, entitled, _Apologia pro circulatione sanguinis contra Æmilianum Parisanum_. He was an active member of the Royal Society, and died, according to Wood, 13th October, 1689.] [Footnote 18: First edit. _Chose by._]