The literary productions of the Gaonic age open with the _Sheeltoth_ written by Achai in the year 760. This, the first independent book composed after the close of the Talmud, was curiously enough compiled in Palestine, whither Achai had migrated from Persia. The Sheeltoth ("Inquiries") contain nearly two hundred homilies on the Pentateuch. In the year 880 another Gaon, Amram by name, prepared a _Siddur_, or Prayer-Book, which includes many remarks on the history of the liturgy and the customs connected with it. A contemporary of Amram, Zemach, the son of Paltoi, found a different channel for his literary energies. He compiled an _Aruch_, or Talmudical Lexicon. Of the most active of the Gaonim, Saadiah, more will be said in a subsequent chapter. We will now pass on to Sherira, who in 987 wrote his famous "Letter," containing a history of the Jewish Tradition, a work which stamps the author as at once learned and critical. It shows that the Gaonim were not afraid nor incapable of facing such problems as this: Was the Mishnah _orally_ transmitted to the Amoraim (or Rabbis of the Talmud), or was it _written down_ by the compiler? Sherira accepted the former alternative. The latest Gaonim were far more productive than the earlier. Samuel, the son of Chofni, who died in 1034, and the last of the Gaonim, Hai, who flourished from 998 to 1038, were the authors of many works on the Talmud, the Bible, and other branches of Jewish literature. Hai Gaon was also a poet. The language used by the Gaonim was at first Hebrew and Aramaic, and the latter remained the official speech of the Gaonate. In course of time, Arabic replaced the Aramean dialect, and became the _lingua franca_ of the Jews.