The Æsculapius of the Egyptians was Imhotep; he was the god of the sciences, and was the son of Ptah and Pakht. The gods of Egypt were worshipped in triads or trinities, and many of the great temples were devoted to the worship of one or other of these trinities, that of Memphis consisted of Ptah, Pakht, and Imhotep. Thoth or Tauut was similar to Imhotep; he was the god of letters, and, as the deity of wisdom, he aids Horus against Set, the representative of physical evil. By many writers he is considered to be the Egyptian Æsculapius. He has some evident relationship to the Greek Hermes. “Thoth,” says Dr. Baas (_Hist. Med._, p. 14), “is supposed to have been the author of the oldest Egyptian medical works, whose contents were first engraved upon pillars of stone. Subsequently collected into the book _Ambre_ or _Embre_ (a title based upon the initial words of this book, viz. ‘Ha em re em per em hru,’ _i.e._ ‘Here begins the book of the preparation of drugs for all parts of the human body’), they formed a part of the so-called ‘Hermetic Books,’ from whose prescriptions no physician might deviate, unless he was willing to expose himself to punishment in case the patient died. This punishment was threatened because the substance of the medical, as well as the religious works of the Egyptians—and the science of the priests united in itself medicine, theology, and philosophy—was given, according to their view, by the gods themselves, and a disregard of their prescriptions would be nothing less than sacrilege.” The Hermetic books, says Clement of Alexandria, were forty-two in number, of which six “of the pastophor” were medical. The famous _Book of the Dead_ is supposed by Bunsen to have been one of the Hermetic books. The papyrus of Ebers, believed by that Egyptologist to date from the year 1500 B.C., is considered to have been of the number of the medical books of Hermes Trismegistus. The Papyrus Ebers is preserved in Leipsic, and, though at present only partially deciphered, abundantly shows the great advance already made at so distant a period as the fourth millennium before the Christian era in the arts of medicine and surgery. One of the authors mentioned in the papyrus is an oculist of Byblos in Phœnicia. This proves not only that there were specialists in diseases of the eye at that period, but that neighbouring nations contributed of their store of scientific knowledge to enrich that of the Egyptians.