DAVY, HUMPHREY. - Born at Penzance, in Cornwall, on 17 December 1778, died at Geneva on 29 May 1829. Of a modest family, he was first an apothecary's apprentice and then an assistant and later head of the laboratory of the Pneumatic Institution in Bristol for the study of the physiological and therapeutic action of gases. He discovered the intoxicating action of laughing gas, or nitrous oxide, which was one of the first general anesthetics: this result opened for him the way to the teaching of chemistry at the Royal Institution in London, which allowed him to devote himself to scientific research with truly exceptional results. He was, along with Hisinger and Berzelius, among the first electrochemists.
He studied the electrolysis of water; by means of the electric current he isolated the alkali and alkaline-earth metals (potassium, sodium, calcium, barium and strontium), boron and chlorine, of which he recognized the nature of a chemical element: at the same time as Gay-Lussac he isolated iodine and recognized its nature as an element. He invented the safety lamp that bears his name and for which he refused to take out patents. He was a member and later president of the Royal Society of London.
Of frail health (also because of the experiments he performed on himself with gases), having become rich through a marriage and famous for his discoveries, he made two journeys to Italy, where he stayed for a long time and met Volta and Morichini.
Of a philosophical mind and a religious spirit, he found the traces of God as creator and provider in nature and in science; he opposed materialism and, although a Protestant, showed genuine sympathy for Catholicism; he published a diary: Consolazioni di viaggio o gli ultimi giorni di un filosofo (It. trans., Milan 1928), in which he set out his spiritualistic ideas; on his tomb he wished only one word to be written: "spero".