oa Al Raz's book on smallpox and measles

Al Razi was the first physician in history to describe in detail the symptoms and signs of smallpox and measles based upon clinical examination. He was the first to dis-tinguish between the two diseases by what is called now ’the differential diagnosis'in “The Book on Smallpox and Measles”. A manuscript of this book is kept now in Lieden University, Netherlands (manuscript #656) and a micro-film copy is in our institute at Aleppo. This book of four-teen chapters was twice translated into Latin in the 18^th century. The third chapter on the symptoms suggesting the exacerbation of smallpox and measles is considered the most important The aim of this study is to reveal the im-portance of this book in the history of Islamic medicine.