Smallpox inoculation or variolation was a great invention of medicine in ancient China. Inoculation against smallpox using material from small-pox patients was probably first practiced by the Chinese in the 10th century. A story was recorded that a Song Dynasty (960-1279) chancellor of China, Wang Dan,summoned physicians from all over the country to try to find some remedy for smallpox. From Mount Emei in Sichuan, a Taoist hermit, known as a " miracle-working doctor" brought the technique of inoculation and introduced it to him.However, the first clear and credible reference to smallpox inoculation in China comes from Douzhen Xinfa written in 1549 by Wan Quan. Inoculation, according tothe historical records, was not widely practiced in China until the reign of Emperor Longqing (1567-1572) during the Ming Dynasty. Powdered smallpox scabs were blown into the noses of the healthy, and they would then develop a mild case of the disease and from then on were immune to it. During the seventeenth century,the practice spread to the Turkish regions, and then to the European countries. The French philosopher Voltaire once praised, "I am informed that the Chinese have practised inoculation in the past hundred years; this is a great precedent and ex-ample set by the Chinese nation considered to be the most intelligent and courteous in the world. "