Preface, and perhaps the Introduction, were added after his arrival at Lisbon, in the brief period before his death. The former is a semi- humorous apology for voyage-writing; the latter gives an account of the circumstances which led to this, his last expedition in search of health. At the beginning of August 1753, Fielding tells us, having taken the Duke of Portland's medicine [Footnote: A popular eighteenth-century gout-powder, but as old as Galen. The receipt for it is given in the _Gentleman's Magazine_, vol. xxiii., 579.] for near a year, "the effects of which had been the carrying off the symptoms of a lingering imperfect gout," Mr. Ranby, the King's Sergeant-Surgeon [Footnote: Mr. Ranby was also the friend of Hogarth, who etched his house at Chiswick.] (to whom complimentary reference had been made in the Man of the Hill's story in _Tom Jones_), with other able physicians, advised him "to go immediately to Bath." He accordingly engaged lodgings, and prepared to leave town forthwith. While he was making ready for his departure, and was "almost fatigued to death with several long examinations, relating to five different murders, all committed within the space of a week, by different gangs of street robbers," he received a message from the Duke of Newcastle, afterwards Premier, through that Mr. Carrington whom Walpole calls "the cleverest of all ministerial terriers," requesting his attendance in Lincoln's-Inn Fields (Newcastle House). Being lame, and greatly over-taxed, Fielding excused himself. But the Duke sent Mr. Carrington again next day, and Fielding with great difficulty obeyed the summons. After waiting some three hours in the antechamber (no unusual feature, as Lord Chesterfield informs us, of the Newcastle audiences), a gentleman was deputed to consult him as to the devising of a plan for putting an immediate end to the murders and robberies which had become so common. This, although the visit cost him "a severe cold," Fielding at once undertook. A proposal was speedily drawn out and submitted to the Privy Council. Its essential features were the employment of a known informer, and the provision of funds for that purpose.