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
The Racecourse Colliery lamp' mines, i.e. the miners would have to make do with tallow candles set in a lump of clay. Mines were run on a day-to-day basis by the butty, this position can be compared to the modern-day contactor who would agree to sell coal to the mine owner at a fixed price. The butty would also hire and fire the men as required and at a pit like this, between six and 30 men could be employed. Every morning before the start of the shift the butty would go down with his safety lamp and check the workings for gases