Mr. Hepworth Dixon's very able and interesting biography of the great Quaker philanthropist, William Penn, contains the best account which has yet been published of the circumstances under which he was imprisoned in the Tower of London in the year 1668. That imprisonment was an event which exercised a most important influence upon the whole of Penn's after life. It attached him to the faith of Quakerism by the strong link of a public persecution suffered on its behalf, and the leisure which it afforded him sobered and matured his mind, and led to the production of a valuable addition to the library of practical Christianity. Up to the period of this imprisonment it seemed not impossible that under judicious treatment William Penn might have been won back to the church from which he had strayed. He had, indeed, openly avowed himself a Quaker, and had published his controversial pamphlets, entitled “Truth Exalted” and “The Guide Mistaken,” but nothing had rendered his adoption of the tenets of “The Friends” too decided to be retreated from with honour. To cut off this retreat was the effect of his imprisonment as a state criminal in the Tower. It pointed him out to the world as one of the heads and leaders of a sect then generally contemned. It nailed his colours to his mast, to borrow a metaphor from the profession of his father, and bound him either to discredit himself by a public recantation under the influence of persecution, or to fight out the battle which was thus openly thrust upon him. Nor was the effect upon his co-religionists more injudicious than that upon himself. The followers of George Fox, disgraced by the wild profanities of such persons as Solomon Eccles, were popularly regarded with scorn. To single out the first man of education and station in the world who had joined their ranks, and to send him to the Tower as a state prisoner, for publishing an ill-considered and abstruse controversial pamphlet, gave importance to what had been previously in the general estimation merely contemptible; and involved the government in a dispute, in which, if it failed to produce recantation, the attempt was sure to recoil with great advantage to the public reputation of both the prisoner and his sect. Viewing this imprisonment as a turning point, both in the personal history of William Penn and in the larger history of the religious community to which he attached himself, I lately received with much thankfulness from my friend and co-fellow of the Society of Antiquaries, Robert Lemon, Esq., of the State Paper Office, some valuable additional information respecting this imprisonment, and I trust it will not be displeasing to the Society of Antiquaries to listen to such an account of these new particulars as I am able to give.