The lingo, called indifferently Thieves' Latin or St Giles's Greek, was assuredly not the invention of one brain. The work of many, it supplied an imperious need. It was at once an expression of pride and a shield of defence. Those who understood it proved by its use that they belonged to a class apart; and, being unintelligible to the respectable majority, they could communicate with one another--secretly, as they hoped, and without fear of detection. Throughout the seventeenth and eighteenth centuries the flash tongue grew and was changed; it crossed the Atlantic with the early settlers, and it has left its marks upon the dialect of the American underworld. But its influence upon the common Slang has been light in America, as in England. It is as severely technical as the language of science, and is familiar chiefly to policemen, tramps, and informers. As Slang leaves the tavern and the street-corner, to invade the theatre, the office, and even the drawing-room, those who aim at a variety of speech need owe no debt to the Cant of the vagabonds, and it is not surprising that to-day the vulgar tongue, in America as in England, borrows more from "soldiers on the long march, seamen at the capstan, and ladies disposing of fish," than from the common cursetors and cony-catchers who once dominated it. The use of Slang proves at once the wealth and poverty of a language. It proves its wealth when it reflects a living, moving image. It proves its poverty when it is nothing more than the vain echo of a familiar catchword. At its best it is an ornament of speech; at its worst it is a labour-saving device. And it is for this reason that the vulgar American delights in the baser kind of Slang: it seems to ensure him an easy effect He must be picturesque at all costs. Sometimes he reaches the goal of his ambition by a purposed extravagance. What can be more foolish than the description which follows of a man equal to the most difficult occasion: "He can light his cigar, when the battle is on, with the friction of a passing cannon-ball." In yet worse taste is another piece of fustian, invented by the same author: "When a 'twister' off the hills gets ready to do business in a 20-knot sou'wester it sends no messenger boys ahead to distribute its itinerary handbills." There is no fault of style which these few lines do not display. They combine, with a singular success, commonness and pomp. The epic poets of old were wont to illustrate the life of man by the phenomena of nature. The vulgar American reverses the process--he illustrates nature from the pavement.