Unfortunately, as the Koran most absolutely prohibited the dissection of dead bodies, all serious anatomical research was thereby rendered impossible. This was a very great hindrance to the progress of anatomy, of physiology, and, in consequence, of the whole of medical science. The Arabians certainly had the merit of keeping alive the study of medicine in an age of decadence and barbarism; but, apart from the important progress realized by them in chemistry and pharmacology, it may be affirmed that the Arabs contributed but scantily to the development of the healing art; they followed almost entirely in the footsteps of Galen and other ancient, and especially Greek, authors. One of the characteristics of Arabian medical art consists in the aversion to bloody operations and in the effort to avoid them. A like tendency shows itself also in the sphere of dentistry; the Arabians, even more than their Greek and Roman predecessors, were reluctant to extract teeth, and employed all possible means, in order to avoid the operation. RHAZES (or more precisely, Abu Bekr Muhammed ben Zacarja er Rhazi) was born in Persia toward the middle of the ninth century, and gave himself up to the study of medicine when about thirty years of age, having previously been a musician. He wrote many works which, unfortunately, have, for the most part, been lost. Rhazes did not have recourse to the extraction of teeth, save as a last resource when every other attempt at cure had proved useless; which method would no doubt have deserved high praise, had the author been inspired by the principles of conservative surgery, rather than by unjustifiable fears. Caries of the teeth is, according to him, identical with that of the bones. To hinder its progress and propagation to the neighboring teeth, he advises the carious cavity to be filled with a “cement” composed of mastic and alum. We have here a laudable attempt at permanent stopping of decayed teeth, although it is clear that the duration of such stopping, owing to the nature of the materials employed, could not be a long one. Furthermore, he counselled the patient to abstain from the use of acid food or drink and to rub the teeth with powder of gall-nuts and pepper. To strengthen loosened teeth, he recommended astringent mouth washes and sundry dentifrice powders. Others, partly taken from Galen, are recommended by him for prophylactic purposes and for cleansing and beautifying the teeth.