Before concluding these prefatory remarks, it will be naturally expected that I should say something of the author whose work I have bestowed so much pains in translating and commenting upon. Here, however, I must regret that the information which I have to supply is exceedingly scanty and unsatisfactory. So little is known of him that it is not even ascertained in what century he flourished. Vossius is wholly undecided; Moreau and Le Clerc place him in the fourth century; Vander Linden and Conringius, in the fifth; but Freind, Albertus Fabricius, Hutcheson, Sprengel, and most of the late writers of the Ancient History of Medicine, bring him down as low as the seventh century, upon the authority of Abulfaragius; but every person who is at all acquainted with his works will agree with me that any opinion of his on chronological matters is entitled to very little consideration indeed. What confidence does a writer deserve who states, for example, that Andromachus, the physician who added the flesh of vipers to the celebrated electuary of Mithridates, lived in the time of Alexander the Great!—that Dioscorides, of Ain Zarba, flourished in the reign of Ptolemy Physcon, namely, about one hundred and twenty years before Christ, whereas it can scarcely admit of a doubt that the celebrated author of the Greek Materia Medica did not live earlier than the end of the first century of the Christian era!—and that Ruffus was contemporary with Plato, when we have the authority of Suidas that he lived in the reign of Trajan! Dr. Milward, in his epistle to Sir Hans Sloane, endeavours to settle the age of our author from the following train of inferences: In the first place, then, since Paulus quotes Alexander Trallian and Alexander Aëtius, it is quite certain that our author was posterior to both these writers. Now the age of Aëtius may be made out from the following circumstances: Aëtius mentions St. Cyril, Archbishop of Alexandria, whose death is ascertained from ecclesiastical history to have happened as late as the middle of the fifth century. Nay, he also takes notice of a medicine much recommended by Petrus Archiater, chief physician to Theodoric, who was posterior to St. Cyril. We cannot possibly suppose it likely, then, that Aëtius flourished earlier than the end of the fifth century. But what brings him still further down, is the circumstance that his predecessor, Alexander, is mentioned by Agathias, the historian, about the middle of the sixth century. (Hist. v, 6.) It would seem almost certain, therefore, taking all these things into consideration, that our Author cannot have lived at an earlier period than in the end of the sixth or the beginning of the seventh century.