I give this outline of preparatory study to show the reason the task has never been undertaken before. People in the present chase after respectability don’t care to turn blackguards, and exchange cards with the Whitechapel Pecker or the Sharp’s-alley Chicken, for the sake of a few vulgar, although curious words; and we may rest assured that it is quite impossible to write any account of vulgar or low language, and remain seated on damask in one’s own drawing room. But a fortunate circumstance attended the compiler of the present work, and he has neither been required to reside in Seven Dials, visit the treadmill, or wander over the country in the character of a vagabond or a cadger. In collecting old ballads, penny histories, and other printed street narratives, as materials for a _History of Cheap or Popular Literature_, he frequently had occasion to purchase in Seven Dials and the Borough a few old songs or dying speeches, from the chaunters and patterers who abound in those neighbourhoods. With some of these men (their names would not in the least interest the reader, and would only serve the purpose of making this Preface look like a vulgar page from the London Directory) an arrangement was made, that they should collect the cant and slang words used by the different wandering tribes of London and the country. Some of these chaunters are men of respectable education (although filling a vagabond’s calling), and can write good hands, and express themselves fluently, if not with orthographical correctness. To prevent deception and mistakes, the words and phrases sent in were checked off by other chaunters and tramps. Assistance was also sought and obtained, through an intelligent printer in Seven Dials, from the costermongers in London, and the pedlars and hucksters who traverse the country. In this manner the greater number of cant words were procured, very valuable help being continually derived from _Mayhew’s London Labour and London Poor_, a work which had gone over much of the same ground. The slang and vulgar expressions were gleaned from every source which appeared to offer any materials; indeed the references attached to words in the Dictionary frequently indicate the channels which afforded them. Although in the Introduction I have divided cant from slang, and treated the subjects separately, yet in the Dictionary I have only, in a few instances, pointed out which are slang, or which are cant terms. The task would have been a difficult one. Many words which were once cant are slang now. The words PRIG and COVE are instances in point. Once cant and secret terms, they are now only street vulgarisms.