And then there was Dr. Wallis, the mathematician, since 1649 Savilian Professor of Geometry. Wallis was about thirty-eight; a man of “moderate principles,” robust and energetic, with a serene temper that was “not easily ruffled,” but all the same a man who could hit out from the shoulder when he wanted to; as he did when he carried on his famous controversy with Dr. Hobbes. Wallis, as a believer in the New Philosophy, was to be among the first men to “maintain the circulation of the blood.” But the particular feat which had made Wallis’s fortune, some years before he went to Oxford, was a feat in “cryptologie.” In December 1642 he was private chaplain to a great family in London; and one evening at supper a cypher letter had arrived, which brought important political news. The Chaplain, in two hours, succeeded in deciphering it; and after that he seems to have become “cryptologist-in-chief” to the Parliamentarian Army: he is said to have had the deciphering of the King’s private correspondence taken at the battle of Naseby. He held successive City livings, was Secretary to the Westminster Assembly, and one of the founders of the Invisible Society. And in 1649—a married man, then—he went to Oxford as Savilian Professor of Geometry and one of the most vigorous of the “learned Junto.” Dr. Goddard of Wood Street was another of them. He was a Deptford man, son of a ship-builder; in 1654 a man of about thirty-seven. He had been a student at Oxford, but had left it to study medicine abroad; and on his return he had taken his medical degrees at Cambridge. Since 1646 he had been in London, a Fellow of the College of Physicians, living in Wood Street, where he entertained the Invisibles and manufactured his _arcana_—the famous “Goddard’s drops” among them—in his own private laboratory. As Cromwell’s physician, he had been with Cromwell in the Irish and Scottish campaigns and in Cromwell’s severe illness in Edinburgh; and on his return with him to London, after the battle of Worcester, he had been appointed Warden of Merton. And living just opposite to Merton College was the Oxford-bred Willis, with his strong royalist and episcopal sympathies, son-in-law of the stubborn old Dean of Christ Church and the lady who had been deposited in the quadrangle. Willis was a greater man in his own profession than the inventor of “Goddard’s drops.” A firm believer in the New Philosophy, he was to dissect many brains: a little bit of our cerebral geography is still known as the “Circle of Willis.” He is the man who discovered _diabetes mellitus_, and he may be called our first specialist in diseases of the nervous system.