History of chemistry iodine first, but both scientists acknowledged Courtois as the first to isolate the element. In 1815, Humphry Davy invented the Davy lamp, which allowed miners within coal mines to work safely in the presence of flammable gases. There had been many mining explosions caused by firedamp or methane often ignited by open flames of the lamps then used by miners. Davy conceived of using an iron gauze to enclose a lamp's flame, and so prevent the methane burning inside the lamp from passing out to the general atmosphere. Although the idea of the safety lamp had already been demonstrated by
Kerosene lamp a mantle to incandescence and also providing heat to the gas generator. The first description of a simple lamp using crude mineral oil was provided by Persian alchemist al-Razi (Rhazes) in 9th century Baghdad, who referred to it as the "naffatah" in his "Kitab al-Asrar" ("Book of Secrets"). In 1846 Abraham Pineo Gesner invented a substitute for whale oil for lighting, distilled from coal. Later made from petroleum, kerosene became a popular lighting fuel. Modern and most popular versions of the kerosene lamp were later constructed by Polish inventor and pharmacist Ignacy Łukasiewicz. Kerosene lamps are widely used for lighting