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
Safety lamp ensure that the wick was lowered and the lamp extinguished by any attempt to open it. The lamp was "much more expensive than the forms of lamp now in general use, but Mr, Yates states that the saving of oil effected by its use will in one year pay the additional cost". The Evan–Thomas lamp is similar to a shielded Clanny, but there is a brass cylinder outside the gauze above the glass. It resists draughts well but the flame is dull. The Morgan is a cross between the Mueseler and the Marsaut. It is a shielded lamp with a