The earliest known writing about medicine was a 110-page Egyptian papyrus. It was supposedly written by the god Thoth in about 16 BC. The Ebers papyrus is an ancient recipe book dated to approximately 1552 BC. It contains a mixture of magic and medicine with invocations to banish disease and a catalogue of useful plants, minerals, magic amulets and spells. The most famous Egyptian physician was Imhotep, who lived in Memphis around 2500 B.C. Imhotep's materia medica consisted of procedures for treating head and torso injuries, tending of wounds, and prevention and curing of infections, as well as advanced principles of hygiene.