According to Humphrey David, he first participated in chemical research in 1798, when Beddoes founded a gas therapy research in Chritton and invited Humphrey David to join. Later, David was mainly responsible for developing various gases in this institute. In this research institute in Chritton, David discovered nitrous oxide, which has anesthetic effect on people. Later, nitrous oxide was widely used in surgery, mainly for pain relief and anesthesia. Humphrey David not only discovered the anesthetic effect of nitrous oxide, but also discovered elements such as sodium, potassium, barium, calcium and magnesium. Moreover, Humphrey David also invented the method of replacing metal by electrolysis, which is widely used in world chemistry. Humphrey David is not only an excellent chemist, but also a visionary. It was he who discovered michael faraday's talent.