It was mainly accident which determined that from the 12th to the 17th century Avicenna should be the guide of medical study in European universities, and eclipse the names of Rhazes, Ali ibn al-Abbas and Avenzoar.
His work is not essentially different from that of his predecessors Rhazes and Ali; all present the doctrine of Galen, and through Galen the doctrine of Hippocrates, modified by the system of Aristotle.
But the Canon of Avicenna is distinguished from the Al-Hawi (Continens) or Summary of Rhazes by its greater method, due perhaps to the logical studies of the former, and entitling him to his surname of Prince of the Physicians.
His son Moses, who died about the end of the 13th century, translated the rest of Maimonides, much of Averroes, the lesser Canon of Avicenna, Euclid's Elements (from the Arabic version), Ibn al-Jazzar's Viaticum, medical works of IIunain ben Isaac (Johannitius) and Razi (Rhazes), besides works of less-known Arabic authors.
The Arabic chroniclers record the names of many other writers on alchemy, among the most famous being Rhazes and Avicenna.
Vincent attributes to Rhazes the statement that copper is potentially silver, and any one who can eliminate the red colour will bring it to the state of silver, for it is copper in outward appearance, but in its inmost nature silver.
Rhazes is deservedly remembered as having first described small-pox and measles in an accurate manner.
Ragel wrote a book on naevi; Rhazes (1040) devoted several chapters to it; and Averroes (1165) made many references to it in his De sanitate, p. 82 (Leiden, 1537).