Actually Hu Gong was a greybeard and medicine peddler who lived in the Eastern Han Dynasty。 He had magical Daoist power and used charms to treat diseases. He often hung a bottle gourd (also called a “calabash” or medicine bottle gourd) to sell medicines in the market with just “one price for all medicines” that would “heal all diseases”, and because of this in later generations “hanging a calabash” became a colloquialism for the practice of Chinese Medicine.

Hanging a calabash on the doctor is like the sign of a Chinese medicine practice, and the Chinese praise practitioners of TCM because they “xuan hu ji shi”----practise medicine in order to help people.

From the History of the Later Han, and the Tales of the immortals)