The World Book Encyclopedia J k volume 11

Jis the tenth letter of our alphabet, and was the last to be added. It developed from the letter I, which was the tenth letter in the alphabet used by the Semites, who once lived in Syria and Palestine. They probably adapted an Egyptian hieroglyphic (picture symbol) meaning hand to represent the letter, but the resemblance is slight. The ancient Greeks used the letter and passed it on to the Romans. In the late Middle Ages, when two or more i's were written together, scribes often added a long tail to the last one. Later, the tail was used to indicate an ini-tial I. During the 1600's, an i at the beginning of a word was written with a tail. The / developed from these forms, and became a symbol for the consonant j, as in joy. See Alphabet.