»If you will allow me the use of slang» is a phrase often heard in English conversation; but in reality a considerable number of original slang and cant expressions are used without any special permission—often without the speaker’s knowing it. There is—as in all languages, and in English much more than in any other—a constant flow from »low class» into »high class» language. A word or an expression, having been long in use exclusively among the working classes, or in the easy talk of certain trades, gradually penetrates into the colloquial speech of the cultivated—sometimes with a slight change of the sense—and suddenly appears one day in refined literary language. In actual English, there are many such expressions, originating partly from cant, partly from slang[2]. Now, what is _slang_, and what is _cant_? When the average Englishman employs the word »slang», he usually means all that he does not regard as »correct» English, all that sounds to his ears more or less vulgar. In reality, a certain confusion seems to have been long prevailing in English conception and English literature concerning »flash» and »cant» (vulgarism) on one side, and »slang» on the other[3]. By =slang=, I mean _the easy, natural, semi-technical language of special classes of society_. In English, as well as in most other languages, there are a great many terms and expressions which are chiefly used in certain trades and professions, and which are often unintelligible to outsiders. Such terms, for instance, are _pater_, _mater_ (father, mother), to be _plucked_ or _ploughed_ (to be rejected in an examination), _tuck_ (sweetstuff), _swot_ (study hard), _slack_ (the contrary of the last-named), _coach_ (private tutor), etc., all in common use among schoolboys. Many of them, such as _chum_, _chummy_, _cheek_, _jaw_ (chatter), _spoon_ (make love), _bunk_ (run away, escape), etc., have exceeded their original sphere and encroached upon common, colloquial language. Among the most important categories of slang, the following may be mentioned: _student-_, _schoolboy-_, _military-_, _commercial-_ and _sporting-slang_. The political world, Parliament, the printing-offices, the stage, nay, even the Church, give their tributes to the vocabulary of slang. The slang-terms are mostly common to all individuals of the same class, but occasionally they differ. Thus, two universities, or even two neighbouring schools, sometimes use different semi-technical terms to express the same idea. By =cant= or =vulgarism= (low-slang) I mean _the easy, natural language of the uneducated people_.