This surely is a refutation as definite as can be desired of a medicine which depends upon witchcraft or astrologic vagaries. However, various other passages of the Corpus Hippocraticum take an exactly contrary position. For example, we find the following statement (on “Air, Water, and Locality,” Chapter XVII., in the translation of Fuchs, Vol. I., page 390): “Attention must be paid to the rise of the stars, especially to that of Sirius,[4] as well as to the rise of Arcturus, and, further, to the setting of the Pleiades, for most diseases reach a crisis during such periods, some of them abating in these days, others ceasing entirely, or developing into other symptoms and different conditions.” These words indicate a distinct intention of bringing prognosis and course of diseases into the closest relations with the motions of the celestial bodies. In the second chapter of the same book similar expressions occur: “He who knows how the change of seasons and the rising and setting of stars take place will also be able to foresee how the year is going to be. Therefore, any one who investigates these subjects and predicts coming events will be thoroughly informed as to each detail of the future; he will enjoy the best of health, and take as much as possible the right road in art. However, if any one should be of the opinion that these questions belong solely in the realm of astronomy, he will soon change his opinion as he learns that astronomy is not of slight, but of a very essential, importance in medical art.” Stars and diseases are also brought into mutual relations in the letter to King Ptolemy (Emerins, page 293). [4] This star, in particular, played a rôle in the astrologic prognosis of the Egyptians; in fact, in various systems it was made the starting-point of medical predictions; for instance, in the method of Hermes Trismegistus. The above quotations refer exclusively to the course of diseases in relation to the stars, but we find in other passages also distinct references are made to therapeutic methods; for instance, in “Aphorisms,” § 4, paragraph 5, we read: “Purging is very difficult during or before the dog-days.”