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
Davy lamp was outside their province. The lamps had to be provided by the miners themselves, not the owners, as traditionally the miners had bought their own candles from the company store. Miners still preferred the better illumination from a naked light, and mine regulations insisting that only safety lamps be used were draconian in principle, but in practice neither observed nor enforced. After two accidents in two years (1838-9) in Cumberland pits, both caused by safety checks being carried out by the light of a naked flame, the Royal Commission on Children's Employment commented both on the failure to learn from