Aaron

, a presbyter of Alexandria, the author of thirty books on physic in the Syriac tongue, which he called the Pandects. They were supposed to be written before 620, and were translated out of the Syriac into Arabic, by Maserjawalh, a Syrian Jew, and a physician in the reign of the calif Merwan, about A. D. 683; for then the Arabians began to cultivate the sciences and to study physic. In these he has clearly described the small-pox, and the measles, with their pathognomonic symptoms, and is the first author that mentions those two remarkable diseases, which probably first appeared and were taken notice of at Alexandria in Egypt, soon after the Arabians made themselves masters of that city, in A. D. 640, in the reign, of Omar Ebnol Chatab, the second successor to Mohammed. But both those original Pandects, and their translation, are now lost; and we have nothing of them remaining, but what Mohammed Rhazis collected from them, and has left us in his Continens; so that we have no certain account where those two diseases first appeared; but it is most probable that it was in Arabia Fcelix, and that they were brought from thence to Alexandria by the Arabians, when they took that city.²