Rhazes was a very hard worker and was highly esteemed by his fellow countrymen, who called him the Arabian Galen. The total number of writings which he left behind him at the time of his death was 237, most of them dealing with medical subjects. A few of them, however, were devoted to the discussion of chemical, anatomical and philosophical questions. To-day we possess only 36 of the treatises written by Rhazes, and of this number only six have been printed in Latin. His greatest work, as all critics admit, is that which is commonly known as the "Continens" (or "El Haouy"). In this work, which is divided into twenty-two books, Rhazes gives in a condensed form the views entertained by all his predecessors regarding the more important questions in medical science, and then adds thereto the conclusions which his own experience has led him to form.
He also wrote a second treatise (in ten books) which was esteemed by the physicians of that and later periods almost as highly as the Continens. It was called the "Mansoury," and its contents are distributed as follows: I., Anatomy; II., the Different Temperaments; III., Alimentary Substances and Drugs; IV., Hygiene; V., Cosmetics; VI., the Regimen to be adopted in Traveling; VII., Surgery; VIII., Poisons; IX., Maladies in General; X., Fevers.
A third treatise of considerable importance is that which is devoted by Rhazes to the description and treatment of small-pox and measles. So far as is known at the present time this is the first treatise that has been written on these diseases, and its celebrity rests, not only upon this circumstance, but also upon the facts that its author is evidently familiar with the different types of small-pox and with the characteristic features which distinguish this disease from measles. Freind, in commenting upon this treatise, says that Rhazes assigned for small-pox a cause "entirely new in physick, a sort of an innate contagion. This is a ferment in the blood, like that in must, which purifies itself sooner or later by throwing off the peccant matter at the glands of the skin; an hypothesis since applied, though upon very slight grounds, to feavers in gen-
