Slang, like everything else, changes much in the course of time; and though but fifteen years have elapsed since this Dictionary was first introduced to the public, alterations have since then been many and frequent in the subject of which it treats. The first issue of a work of this kind is, too, ever beset with difficulties, and the compiler was always aware that, though under the circumstances of its production the book was an undoubted success, it necessarily lacked many of the elements which would make that success lasting, and cause the "Slang Dictionary" to be regarded as an authority and a work of reference not merely among the uneducated, but among people of cultivated tastes and inquiring minds.