In the circles of the priests the traditional invocations of the gods, the rules for the proper conduct of sacrifices and feasts, for the pure conversation which is the way to life and salvation in this world and the next, were without doubt committed to writing at a very early period. When gradually extended and continued, those writings grew into a liturgical canon and ecclesiastical codex of religious and moral law, and a comprehensive collection of all the wisdom known to the priests. We learn that the Egyptian priests possessed forty-two sacred books. Regarded as a collection of religious rules in every department of civilisation and life, as the measure of holy and upright conversation, and as rules of civil law, these books passed as the writings of the god Thoth, the scribe of heaven, the god of truth and justice. The civil law also was grounded upon the rules and axioms of religion; from these it arose, and the books of civil law without doubt formed a part of the sacred law, and of the books of the priests. Of these forty-two books ten belonged to the high priest, of which eight may have been the eight books of civil law (p. 202). In that case the two others would contain the doctrine concerning the gods, and the instruction of the priests. Ten other books belonged to the temple-scribe. Of these the first contained the rules for the sacred writing; the second the geography and cosmogony; the third and fourth the arrangement of the sun, moon, and five planets; the fifth and sixth the description of Egypt and the Nile; the seventh, eighth, ninth, and tenth, the weights and measures, the mode of registering the temple furniture and property. Again, ten books belonged to the chamberlain. These taught the ritual and the liturgy, the offering of first-fruits and sacrifices, hymns and prayers, together with the conduct of festivals and other things of the kind, and, finally, discipline and the rules for examining the animals for sacrifices. The two books of the minstrel contained the hymns and the contemplation of the life proper for a king (p. 188). The four books of the astrologer concluded the narrower circle of the sacred writings. Of these, the first contained the arrangement of the fixed stars; the second and third the coincidences of the orbits of the sun and moon; the fourth, the rising of the constellations. Besides these sacred books the pastophors (p. 196) had six books which taught the principles and practice of medicine;[280] for the art of healing, _i.e._ of preserving life, also belonged to the priests. The medicine of the Egyptians is commended as early as the Homeric poems (p. 15). Herodotus assures us that in Egypt every kind of sickness had a special physician, and Diodorus states that the art was carried out strictly according to the written principles, _i.e._ no doubt, according to these six sacred books. A hieratic papyrus on the subject of medicine has been recently