A HISTORY OF SCIENCE 



duced by the hollow bone behind the ear ; for all hollow 

 things are sonorous." He was a rationalist, and he 

 taught that the brain is the organ of mind. The 

 sources of our information about his work, however, 

 are unreliable. 



Democedes, who lived in the sixth century B.C., is 

 the first physician of whom we have any trustworthy 

 history. We learn from Herodotus that he came from 

 Croton to ^Egina, where, in recognition of his skill, he 

 was appointed medical officer of the city. From 

 ^Egina he was called to Athens at an increased salary, 

 and later was in charge of medical affairs in several 

 other Greek cities. He was finally called to Samos by 

 the tyrant Poly crates, who reigned there from about 

 536 to 522 B.C. But on the death of Poly crates, who 

 was murdered by the Persians, Democedes became a 

 slave. His fame as a physician, however, had reached 

 the ears of the Persian monarch, and shortly after his 

 capture he was permitted to show his skill upon King 

 Darius himself. The Persian monarch was suffering 

 from a sprained ankle, which his Egyptian surgeons 

 had been unable to cure. Democedes not only cured 

 the injured member but used his influence in saving 

 the lives of his Egyptian rivals, who had been con- 

 demned to death by the king. 



At another time he showed his skill by curing the 

 queen, who was suffering from a chronic abscess of long 

 standing. This so pleased the monarch that he offered 

 him as a reward anything he might desire, except his 

 liberty. But the costly gifts of Darius did not satisfy 

 him so long as he remained a slave ; and determined to 

 secure his freedom at any cost, he volunteered to lead 



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