Humphry Davy experiments with lamps for use…

Humphry Davy experiments with lamps for use in coal mines after his return to England in 1815.

There have been many mining explosions caused by firedamp or methane, often ignited by open flames of the lamps then used by miners.

In particular, the Felling mine disaster in 1812 near Newcastle had caused great loss of life, and action is needed to improve underground lighting and especially the lamps used by miners.

Davy conceives 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 William Reid Clanny in May and imminently by the unknown (but later very famous) engineer George Stephenson, Davy's use of wire gauze to prevent the spread of flame will be used by many other inventors in their later designs.

George Stephenson's lamp will become very popular in the northeast coalfields, and use the same principle of preventing the flame reaching the general atmosphere, but by different means.

Unfortunately, although the new design of gauze lamp initially does seem to offer protection, it gives much less light, and quickly deteriorates in the wet conditions of most pits.

Rusting of the gauze quickly makes the lamp unsafe, and the number of deaths from firedamp explosions will rise yet further.

In 1815 also, Davy suggests that acids are substances that contain replaceable hydrogen—hydrogen that can be partly or totally replaced by metals.

When acids react with metals they form salts.

Bases are substances that react with acids to form salts and water.

These definitions will work well for most of the nineteenth century.