How obsessed were people with alchemy in the Ming Dynasty?

Matteo Ricci said in the Missionary History of China in the Late Ming Dynasty that many people in China were addicted to alchemy at that time, and some even went crazy. "They believe that mercury can be turned into silver, as long as some kind of grass made in foreign countries is used." Seeing that missionaries don't steal, rob, engage in production, don't want money, don't do business, and the living expenses are endless, they speculate that missionaries have brought that kind of grass from abroad and know the secret of alchemy. Matteo Ricci mentioned: "among the parishioners in Zhaoqing, there are two people, father and son, who are engaged in the study of gold." Before they became religious, they burned all the furniture for an alchemist, but they still wouldn't give up. The two men came to see Martin and asked the priests if they really knew the secret of alchemy. In order to deceive them, he said there was no doubt. He also said that Father Luo Ming Sword had promised to teach them the secret recipe of gold, provided that he could not reveal it to anyone. The father and son really believe it and are very concerned about Martin. " Matteo Ricci also mentioned that Qu, a son of Shangshu, "dreamed of learning a set of alchemy" and began to associate with Jesuits (including Li himself). "At the beginning of the communication, Qu didn't want people to know that his purpose was to learn alchemy from westerners. At that time, there were rumors that Father Li would make silver, but because of his association with priests, he gave up his previous behavior and used his talents for more serious and noble science. "