The Egyptians had considerable knowledge of many drugs and medicines, and the physicians of Egypt had a great reputation among the ancients; for every doctor was a specialist and pursued his subject and his practice to the utmost limit of fact and theory. But the physician must treat cases according to customs already established in the past. There was but little opportunity for the advancement of his art. Yet it became very much systematized and conventionalized. The study of anatomy developed also the art of embalming, one of the most distinctive features of Egyptian civilization. This art was carried on by the regular physicians, who made use of resins, oils, bitumens, and various gums. It was customary to embalm the bodies of wealthy persons by filling them with resinous substances and wrapping them closely in linen {184} bandages. The poorer classes were cured very much as beef is cured before drying, and then wrapped in coarse garments preparatory to burial. The number of individuals who were thus disposed of after death is estimated at not less than 420,000,000 between 2000 B.C. and 700 A.D. _The Contribution to Civilization_.--The building of the great empires on the Tigris and Euphrates had a tendency to collect the products of civilization so far as they existed, and to distribute them over a large area. Thus, the industries that began in early Sumer and Akkad, coming from farther east, were passed on to Egypt and Phoenicia and were further distributed over the world. Especially is this true in the work of metals, the manufacture of glass, and the development of the alphabet, which probably originated in Babylon and was improved by the Phoenicians, and, through them as traders, had a wide dispersion. Perhaps one ought to consider that the study of the stars and the heavenly bodies, although it led no farther than astrology and the development of magic, was at least a beginning, although in a crude way, of an inquiry into nature.