their works. Their compositions are full of thought, but their diction is rather crude. Nathan, son of the above-mentioned Rabbi Jehiel, was the author of a Talmudic lexicon ("'Aruk") that became the key to the study of the Talmud. During his residence at Salerno, Solomon ben Abraham ibn Parhon compiled a Hebrew dictionary. This encouraged Italian Jews to study Biblical exegesis. On the whole, however, Hebrew literary culture was not flourishing. The only liturgical author of merit was Joab ben Solomon, some of whose compositions are extant. Toward the second half of the 13th century, signs appeared of a better Hebrew culture and of a more profound study of the Talmud. Isaiah di Trani the Elder (1232–1279), a high Talmudic authority, wrote many celebrated responsa. David, his son, and Isaiah di Trani the Younger, his nephew, followed in his footsteps, as did their descendants until the end of the seventeenth century. Meïr ben Moses presided over an important Talmudic school in Rome, and Abraham ben Joseph over one in Pesaro. In Rome two famous physicians, Abraham and Jehiel, descendants of Nathan ben Jehiel, taught the Talmud. Paola dei Mansi, one of the women of this gifted family, also attained distinction; she had considerable knowledge of the Bible and Talmud, and she transcribed Biblical commentaries in a notably beautiful handwriting (see Jew. Encyc. i. 567, s.v. Paola Anaw). During this period, the Holy Roman Emperor Frederick II, the last of the Hohenstaufen, employed Jews to translate from the Arabic philosophical and astronomical treatises. Among the translators were Judah ben Solomon ha-Kohen of Toledo, later of Tuscany, and Jacob Anatoli of Provence. This encouragement naturally led to the study of the works of Maimonides—particularly of the "Moreh Nebukim"—the favorite writer of Hillel of Verona (1220–1295). This last-named litterateur and philosopher practised medicine at Rome and in other Italian cities, and translated several medical works into Hebrew. The liberal spirit of the writings of Maimonides had other votaries in Italy; e.g., Shabbethai ben Solomon of Rome and Zerahiah Ḥen of Barcelona, who migrated to Rome and contributed much to spread the knowledge of his works. The effect of this on the Italian Jews was apparent in their love of freedom of thought and their esteem for literature, as well as in their adherence to the literal rendering of the Biblical texts and their opposition to fanatical cabalists and mystic theories. Among other devotees