Acacia has been an article of commerce since the most remote records of historical antiquity. Representations of the Acacia tree, together with heaps of gum, were pictured in the reign of Ramses III of Egypt. Acacia was exported from the Gulf of Aden, seventeen hundred years before Christ. Mention of the gum is of frequent occurrence in Egyptian inscriptions, where it is referred to as the Gum of Canaan. Theophrastus (633), in the third and fourth centuries before Christ, described it, as also did Dioscorides (194) and Pliny (514), under the name "Egyptian Gum." It has been employed in the arts from all time and in domestic medicine and commerce, as well as by the Arabian physicians and those of the renowned school of Salerno. During the Middle Ages it was obtained from Egypt and Turkey, being an article of commerce in the bazaars of Constantinople, A. D. 1340. The drug was distributed through Europe from Venice, as early as A. D. 1521. Among the most interesting and instructive recent contributions to the subject are the reports of the Wellcome Research Laboratory, Kartoum (678), 1904.