Argot pervades the whole of French society. It may be heard everywhere, and it is now difficult to peruse a newspaper or open a new novel without meeting with a sprinkling of some of the jargon dialects of the day. These take their rise in the slums, on the boulevards, in workshops, barracks, and studios, and even in the lobbies of the Houses of Legislature. From the beggar to the diplomatist, every class possesses its own vernacular, borrowed more or less from its special avocations. The language of the dangerous classes, which so often savours of evil or bloody deeds, of human suffering, and also of the anguish and fears of the ever-tracked and ever-watchful criminal, though often disguised under a would-be humorous garb, cannot but be interesting to the philosopher. “Everybody,” says Charles Nodier, “must feel that there is more ingenuity in argot than in algebra itself, and that this quality is due to the power it possesses of making language figurative and graphic. With algebra, only calculations can be achieved; with argot, however ignoble and impure its source, a nation and society might be renovated.... Argot is generally formed with ability because it is the outcome of the urgent necessities of a class of men not lacking in brains.... The jargon of the lower classes, which is due to the inventive genius of thieves, is redundant with sparkling wit, and gives evidence of wonderfully imaginative powers.” If criminals are odious, they are not always vulgar, and a study of their mode of expression possesses certain features of interest. The ordinary slang of the higher strata of French society, as compared with that of the lower classes, being based often on mere distortion of words or misappropriation of meaning, is in many cases vulgar and silly; it casts a stain over a language which has already suffered so much at the hands of the lesser stars of the Naturalistic School. A coarse sentiment, a craving for more violent sensations, will find expression in the jargon of the day. People are no longer content with being astonished, they must be crushed or flattened (épatés), or knocked over (renversés), and so forth; and the silly “on dirait du veau,” repeated _ad nauseam_, seldom fails to raise a laugh. Our English neighbours do not seem to be better off. “So universal,” says a writer in _Household Words_, September 24, 1853, “has the use of slang terms become, that in all societies they are substituted for, and have almost usurped the place of wit. An audience will sit in a theatre and listen to a string of brilliant witticisms with perfect immobility, but let some fellow rush forward and roar out ‘It’s all serene,’ or ‘catch’em alive, oh!’ (this last is sure to take), pit, boxes, and gallery roar with laughter.” It must be said, however, on the other hand, that the slang term is often much more expressive than its corresponding synonym in the ordinary language. Moreover, it is often