The oracle Serapis was situated near Canopus; it was visited with the highest veneration by the wealthiest and most illustrious Egyptians, and contained ample records of miraculous cures which that god had performed on sleepers.[98] Isis, it is said, effected similar cures in her lifetime, whence it became her office, in her after state of deification, to reveal in dreams the most efficacious remedies to the sick. Indeed the healing powers of this goddess were such, that, as we are told by Diodorus,[99] the remedies she prescribed never failed of their effect, and that convalescents were daily seen returning from her temple, many of whom had been abandoned as incurable by the physicians. The third oracle of the sick was consecrated to Phthas, and lay near Memphis, but it is seldom mentioned by the ancients.[100] In Italy there existed two oracles, whose responses were imparted in dreams, before the worship of Esculapius was introduced from Greece. One of them only belongs to this place, that of the physician Podalirus, in Daunia,[101] which is mentioned by Lycophron.[102] Subsequently it is well known incubation was practised after the Grecian form in the Roman temple of Aesculapius on the Insula Tiberina.[103] This description of oracles abounded throughout Greece; the most memorable of which was that on the Asiatic coast, between Trattis and Nyssa, which is more particularly described by Strabo than any other. Not far from the town of Nyssa, says he, there is a place called Charaka, where we find a grove and temple sacred to Pluto and Proserpine, and close to the grove a subterraneous cave, of a most extraordinary nature. It is related of it, that diseased persons, who have faith in the remedies predicted by those deities, are accustomed to resort to it and pass some time with experienced priests, who reside near the cave. These priests lay themselves down to sleep in the cave, and afterwards order such medicine as have been revealed to them there, to be furnished to their patients in the temple. They frequently conduct the sick themselves into the cave, where they remain for several days together, without touching a morsel of food; nor are the profane withheld from a participation in the _divinatory_ sleep, though this is not permitted otherwise than under the controul, and with the sacred sanction, of the priests. There is, however, nothing more surprising about this place than that it is esteemed _noxious and fatal to the healthy_.[104] This last remark of our geographer, proves how jealous the priestly physicians were of their medical monopoly, and how fearful lest the _saner_ part of mankind should detect and expose the pretended virtues of their medical sanctuary.