Willow bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and in Ancient Greece the physician Hippocrates wrote about its medicinal properties in the fifth century BC. Native Americans across the Americas relied on it as a staple of their medical treatments. It provides temporary pain relief. Salicin is metabolized into salicylic acid in the human body, and is a precursor of aspirin. In 1763, its medicinal properties were observed by the Reverend Edward Stone in England. He notified the Royal Society, which published his findings. The
Hippocrates to Galen, a later physician, Polybus was Hippocrates' true successor, while Thessalus and Draco each had a son named Hippocrates (Hippocrates III and IV). Soranus said that Hippocrates learned medicine from his father and grandfather (Hippocrates I), and studied other subjects with Democritus and Gorgias. Hippocrates was probably trained at the asklepieion of Kos, and took lessons from the Thracian physician Herodicus of Selymbria. Plato mentions Hippocrates in two of his dialogues: in "Protagoras", Plato describes Hippocrates as "Hippocrates of Kos, the Asclepiad"; while in "Phaedrus", Plato suggests that "Hippocrates the Asclepiad" thought that a complete knowledge of the nature