develop themselves more fully and to spread more extensively from the end of the eighth and the commencement of the ninth centuries. Towards the close of the eighth century came into existence 1. The celebrated mystical work entitled the Alphabet of Rabbi Akiba, which alternately treats each letter of the Hebrew Alphabet as representing an idea as an abbreviation for a word (‏נוטריקון‎), and as the symbol of some sentiment, according to its peculiar form, in order to attach to those letters moral, theoanthropic, angelogical and mystical notions. This work has recently been reprinted in two recensions in Jellinek’s Beth Ha-Midrash, vol. iii, p. 12–64, Leipzig, 1855. 2. The Book of Enoch which describes the glorification of Enoch and his transformation into the angel Metatron, regarding him as ‏ידו״ד הקטון‎ the Minor Deity, in contradistinction to ‏ידו״ד הגדול‎ the Great God and which was originally a constituent part of the Alphabet of R. Akiba. It is reprinted in Jellinek’s Beth Ha-Midrash, vol. ii, pp. 114–117. Leipzig, 1853. 3. Shiur Koma (‏שיעור קומה‎), or the Dimensions of the Deity, which claims to be a revelation from the angel Metatron to R. Ishmael, and describes the size of the body and the sundry members of the Deity. It is given in the Book Raziel (‏ספר רזיאל‎) of Eleazer b. Jehudah of Worms, printed at Amsterdam, 1701, and at Warsaw, 1812. 4. The Palaces (‏היכלות‎). This mystical document opens with an exaltation of those who are worthy to see the chariot throne (‏צפיית המרכבה‎), declaring that they know whatever happens and whatever is about to happen in the world; that he who offends them will be severely punished; and that they are so highly distinguished as not to be required to rise before any one except a king, a high priest, and the Sanhedrim. It then celebrates the praises of Almighty God and his chariot throne; describes the dangers connected with seeing this chariot throne (‏מרכבה‎); gives an episode from the history of the martyrs and the Roman emperor Lupinus, a description of the angels, and of the sundry formulæ wherewith they are adjured. Whereupon follows a description of the seven heavenly palaces, each of which is guarded by eight angels, and into which the student of the mysterious chariot throne may transpose himself in order to learn all mysteries, a description of the formulæ by virtue of which these angelic guards are obliged to grant admission into the celestial palaces, and of the peculiar qualifications of those who desire to enter into them. The document then concludes with detailing some hymns of praise, a conversation between God, Israel, and the angels about those mysteries, a knowledge of which makes man suddenly learned without any trouble, and with a description of this mystery, which consists in certain prayers and charms. This mystical production has also been reprinted in Jellinek’s valuable Beth Ha-Midrash, vol. iii, pp. 83–108.