Commas are used to denote extracts or quotations from other works, dialogue matter, or passages or expressions not original, by placing two of them inverted before the first word of the passage quoted, the ending being denoted by two apostrophes. A thin space is used to keep the inverted commas free from the matter. The method of running them down the sides to the end of the quotation has been found inconvenient, especially where a quotation occurs within a quotation, or a speech within a speech: the proper method of distinguishing these is by placing a single inverted comma before the extra quotation, and concluding with a single apostrophe. Where both quotations end together, put three apostrophes, observing after the first to place a thin space. Inverted commas were first used by Guillemet, a Frenchman, to supersede the use of Italic letter in emphasized words. As an acknowledgment, his countrymen call them after his name. French founders cast them double, thus [«»]. MacKellar, Smiths & Jordan, Philadelphia, furnish them in this way when desired. A single comma inverted is improperly used as an abbreviation of the word Mac, as in M’Gowen: c is preferable, as McGowen. The SEMICOLON [;] denotes a pause greater than that of a comma, and is used between dependent clauses of compound sentences. The COLON [:] is employed in a sentence between clauses less connected than those which are divided by a semicolon, but not so independent as separate, distinct sentences. The PERIOD or FULL-POINT [.] serves to indicate the end of a complete sentence. When used in abbreviations, it has no effect as a full stop in the punctuation, unless at the end of a sentence. In some works this point is discarded as a mark of abbreviation, as in Mr Dr &c. Full-points are sometimes used as leaders in tables of contents, figure-work, &c.; but dotted rules or leaders are more economical for this purpose, as they save considerable time in the composition. The sign of INTERROGATION [?] is used to denote a question. Every interrogation or question should begin with a capital letter, (unless several questions follow one another in connected succession,) according to the method observed in the Bible, where questions and responses, and the beginning of sayings, &c. are denoted by a capital letter. The sign of ADMIRATION or EXCLAMATION [!] denotes surprise, astonishment, rapture, and other sudden emotions of the mind, whether of joy or sorrow. This sign is put after the interjections Ah! Alas! Oh! &c.; but there are exceptional cases, as, Ah me! Alas the day! &c. All the points, except the comma and the period, should be preceded by a hair-space; the comma and full-point do not require any space to bear them off. The em dash [—], though not ranked as a point, is often used by careless writers as a substitute for a comma or semicolon. It may be properly employed in parenthetical sentences, and in rhapsodical writing abounding in disconnected sentences.