J

J J (j[=a]). J is the tenth letter of the English alphabet. It is a later variant form of the Roman letter I, used to express a consonantal sound, that is, originally, the sound of English y in yet. The forms J and I have, until a recent time, been classed together, and they have been used interchangeably. [1913 Webster]

Note: In medical prescriptions j is still used in place of i at the end of a number, as a Roman numeral; as, vj, xij. J is etymologically most closely related to i, y, g; as in jot, iota; jest, gesture; join, jugular, yoke. See {I}. J is a compound vocal consonant, nearly equivalent in sound to dzh. It is exactly the same as g in gem. See Guide to Pronunciation, [sect][sect] 179, 211, 239. [1913 Webster]