Like the mediaeval Christians, they looked with horror on dissection of the human body; yet there were always among them investigators who turned constantly to nature herself for hidden truths, and were ready to uphold the superiority of actual observation to mere reading.

Thus the physician Abd el-Letif, while in Egypt, made careful studies of a mound of bones containing more than twenty thousand skeletons.

While examining these bones he discovered that the lower jaw consists of a single bone, not of two, as had been taught by Galen.

He also discovered several other important mistakes in Galenic anatomy, and was so impressed with his discoveries that he contemplated writing a work on anatomy which should correct the great classical authority's mistakes.
It was the Arabs who invented the apothecary, and their pharmacopoeia, issued from the hospital at Gondisapor, and elaborated from time to time, formed the basis for Western pharmacopoeias.

Just how many drugs originated with them, and how many were borrowed from the Hindoos, Jews, Syrians, and Persians, cannot be determined.