PUNCTUATION, the art of "pointing" a literary composi tion so as to divide it into sentences and portions of sentences, which the "points" mark at their close, thus indicating what would in speech be pauses or changes of expression (Lat. punctum, a point). The uses of the chief "points" are thus explained in the "Rules for Compositors" at the Oxford University Press, compiled by Mr. Horace Hart : The "full stop" or "period" (.) marks the end of a sentence. The "colon" ( :) is at the transition point of the sentence. The "semicolon" ( ;) separates different statements. The "comma" (,) separates clauses, phrases and particles. (The terms "period," "colon," "comma," were borrowed from the Greek grammarians, who originally described either the whole sentence or a part of it in this way.) The "dash" (—) marks abruptness or irregularity. The "exclamation" ( !) marks surprise. The "interrogation" or "query" (?) asks a question. The apostrophe (') marks elisions or the possessive case. "Quotes," quotation-marks or "inverted
commas" (" ") define quoted words. Interpolations in a sentence are marked by various forms of bracket () or parenthesis. Usage and practice vary however. The subject may be studied in such works as H. Beadnell's Spelling and Punctuation, P. Allardyce's Stops: or how to punctuate, and T. L. de Vinne's Correct Compo sition. In the earlier forms of writing the letters ran on continu ously in lines; only by degrees were words divided up by spacing within the line; later came the distribution into sentences by points, and the introduction by Aldus Manutius (i6th century) of a regular system for these. The chief signs were derived from the dots of the Greek grammarians, but these have often changed meanings ; thus the Greek interrogation mark ( ;) be comes the semicolon. (See PALAEOGRAPHY and TYPOGRAPHY.)