How did Hunan people develop the custom of chewing betel nut?

"Xiangtan County Records" records: "In the forty-four years of Qing Qianlong (AD 1779), there was a great epidemic in Xiangtan, and many people had abdominal distension. The county magistrate Bai Jing was proficient in medical skills and knew the medicinal properties. He chewed betel nut for the patient and later recovered. " With the widespread spread of betel nut disease, the habit of chewing betel nut gradually passed down.