When civilization, later on, continued to thrive upon the shores of the Nile, astrology still found a fertile soil there, and it appears that here also the name Ἰατρομαθηματικοί has originated, which, subsequently, was a favorite designation of adherents to the sidereal art of healing. The astrological prognoses made by the professional astrologist, Petosiris, for the king Nechepso of Sais are well known. However, it appears, according to the latest investigations (compare the excellent work of Sudhoff, page 4, etc.), that these prognoses have nothing at all to do with that king Nechepso who reigned in the seventh century, B.C. It seems more probable that some cunning Alexandrian astrologist of the second century, B.C., fraudulently used the name of the king as a cover for his work. But however this may be, these prognoses of Petosiris have considerable value, in that they give us an insight into the manufacture of such medical prophesies. The object of these prognoses was primarily to discover the termination of a disease, whether the patient would die or recover, either soon or only after the lapse of a certain time—for instance, after seven days. This was all that Petosiris undertook to predict. All details regarding treatment, complications, and diagnosis of a case are still entirely wanting. Petosiris, in making such a prognosis, by no means relied solely upon the conjunction of certain celestial bodies, but he employed a rather intricate method, in which mystic numbers, onomancy, and astrology were important elements. To prognosticate medically according to this system a circle of numerals was required in the first place. There existed two different kinds of such circles—one simple, the other more complicated. Berthelot has furnished us with examples of both as used by Petosiris. [Illustration: FIG. 1—CIRCLE OF PETOSIRIS (After Bouché-Leclercq, p. 539)] The more simple formula (Fig. 1) consisted of two concentric circles, the smaller of which was divided into four quadrants. Between both concentric circles and within the horizontal diameters were inscribed the words: μέον ζωή; to the right of this: ἡ μικρὰ ζωή; to the left of the vertical line: ἡ μεναλη ζωή. Under the vertical line was inscribed: μέσος θάνατος; to the right of this: μικρὸς θάνατος; and to the left of the vertical line: ὁ μένας θάνατος. Only words which point to the longer or shorter duration of life, or to the death-struggle, were therefore employed. The four quadrants of the enclosed circle, as well as the vertical diameter, contained the numerals from 1 to 29 in a mystical order, representing the duration of the moon’s phases. The above (Fig. 1) shows us this astrological circle of Petosiris.